the gutless, bloated, and fried power supply hall of shame

[momaka]

Re: the gutless, bloated, and fried power supply hall of shame

Deer DR-8500BTX (MAX 500W)

not able to output any watts in specs here

With one output cap per rail and that small output inductor, it's not surprising. Junk!

And it's a shame, because the primary side probably could do 200-250 Watts. With good parts on the secondary and proper filtering, even a 200-250 Watt PSU can be plenty for many office systems and entry-level gaming PCs.

I mean, they really went out of their way for this one and did all kinds of extra work to still produce a shitty PSU.

- Added a seperate PCB for input filtering
- 4 "fat" diodes for input rectifier bridge
- real output rectifiers, no "2-diodes-on-a-plate" jobby
- The caps were good enough to last for a couple of years it seems
- A label completely dedicated to this one PSU version

I mean, they even painted the case and glued the fuse down. That's some serious build quality you don't expect from a Deer unit.

That's the sad part. It's like they tried and *almost* could make a decent usable unit, but then stopped short of that and ended up with the current POS instead. It makes ZERO sense.

These crapbox PSUs still exist in 2020?

They always will.
As long as there are suckers to buy them (and believe me, there are - especially in this day and age where buying questionable cheap Chinese products from eBay and Amazon is considered a norm), we will keep seeing them.

but if those "Y caps" are generic 1KV or 2KV DC parts instead of agency-approved safety caps, .

Don't think it's a question of "if". Pretty sure they are ceramic caps, looking at how skinny they look. Proper Y2-class caps are usually quite a bit "fatter".

Force DR-8460BTX (MAX 450W) v2.2

The fan stopped but the psu continued working till it almost burnt itself to death.

WOW!

I wonder what this PSU was powering for so long, though. You'd think with that crappy filtering and bad caps, the constant PC crashes/instability would have made the owner realize something is wrong with the PSU and replaced it.

Instead, it was ran until it turned into Deer kebab.

I recently bought 2 shallow ATX power supplies, hoping that they were better than the YoungYear unit i'm currently using. Unfortunately that wasn't the case...

The PCB layout however did have some potential for becoming a decent compact unit. After pulling some components from some other (broken) power supplies, i did the following upgrades:

...

+5VSB: 1x 470uF 16V ChengX, not looked any further -> same
-12V: 1x 470uF 16V ChengX, NO PI Coil -> 1x 2200uF 16V Teapo SC, added PI Coil

Hmmm.
If it was my unit, I would have put that 2200 uF cap on the 5VSB rail. 5VSB caps see far more stress than any other rail, since it is always On and filters a flyback design (higher ripple current output.)
The -12V rail no one cares about. Just has to be there and not too out of spec to trip UV/OV protections. Same goes for the -5V rail.

After making all these changes, it didn't start anymore. It turned out that the controller was entering a protection. The bigger output inductor did not have a winding for the -5V rail. Now, that isn't a problem since modern hardware does not use this voltage rail anymore. But the controller was entering it's UVP protection for the negative rails. Connecting the supervising pin for these negative rails directly to ground fixed it.

Another option you can do if you want to keep the -5V rail (for legacy purposes) is to install a 7905 voltage regulator and use the -12V rail to generate -5V with the 7905 regulator. Plus, it's easy - just mount the 7905 on the secondary heatsink and run wires from -12V, -5V, and GRND to the appropriate pins.

I've done a quick 15 minute stress test run with the following hardware:

- Intel Pentium D overclocked to 4GHz with 1.45Vcore (used this as the variable load)
- Gigabyte X48T-DQ6
- 4x2GB RAM
- NVidia Geforce GT640
- 2x IDE HDD

Using a current clamp i got the following load numbers:
12V (12.09): 18.5A / 222W
5V (4.99): 5A / 25W
3.3V (3.25): 8A / 26.5W
Total power: 273.5W (~275W)

...

Temperature wise, the power supply could probably use a bigger secondary heatsink, the fan ramps up nicely:

60c Primary heatsink
60c Transformer
75c Secondary heatsink
80c Output inductor
PFC coil: Toasty

I can call it a win this time.

Those are not bad results at all. Pulling 220 Watts from the 12V rail is actually impressive given how compact this unit is. Not surprised at all with the temperatures. Now put it in a Core 2 Duo box that uses no more than 100 Watts, and this PSU will probably have a very long life and run much cooler.

[bauto601]

Re: the gutless, bloated, and fried power supply hall of shame

I recently bought 2 shallow ATX power supplies, hoping that they were better than the YoungYear unit i'm currently using. Unfortunately that wasn't the case...

The PCB layout however did have some potential for becoming a decent compact unit. After pulling some components from some other (broken) power supplies, i did the following upgrades:

NO PFC -> Passive PFC
2x Y capacitor -> same
NO X capacitor -> added X capacitor
1x common mode choke -> 1x better wound common mode choke
2x 2.5A diode -> KBL406 rectifier bridge
2x 4A diode -> see above
2x 470uF 200V Ltec primary caps -> same
2x 13007 primary transistors -> 2x D304X primary transistors (still TO220)
1x SVD2N60F mosfet -> same (but primary heatsink has been swapped)

ERL33 transformer -> ERL35 transformer (swapped the primary snubber circuit together with it)
Small output inductor -> bigger output inductor
SC6105 switching controller -> who would swap a controller? Not me
NO fan control -> added fan control

12V: MOSPEC F16C20C 16A TO220 Fast Recovery rectifier -> DSSK 40-008B 40A 80V TO-247 Schottky rectifier
5V: MOSPEC S30D45CS 30A TO247 Schottky rectifier -> same, 5V is already beefy enough
3.3V: Advanced Power AP40N03GP 40A mosfet (tapped from 5V) -> same, also beefy enough

12V: 1x 1000uF 16V ChengX, PI Coil -> 1x 2200uF 16V Teapo SC, 1x 470uF 16V ChengX, PI Coil
5V: 2x 1000uF 10V ChengX, PI Coil -> 2x 3300uF 6.3V Panasonic FS, PI Coil
3.3V: 1x 1000uF 10V ChengX, PI Coil -> 1x 3300uF 6.3V Panasonic FS, PI Coil

+5VSB: 1x 470uF 16V ChengX, not looked any further -> same
-12V: 1x 470uF 16V ChengX, NO PI Coil -> 1x 2200uF 16V Teapo SC, added PI Coil
-5V: 1x 470uF 16V ChengX, NO PI Coil -> still there, just not used anymore

After making all these changes, it didn't start anymore. It turned out that the controller was entering a protection. The bigger output inductor did not have a winding for the -5V rail. Now, that isn't a problem since modern hardware does not use this voltage rail anymore. But the controller was entering it's UVP protection for the negative rails. Connecting the supervising pin for these negative rails directly to ground fixed it. The voltage selector switch on the rear is also removed in order to make room for the PFC coil

I've done a quick 15 minute stress test run with the following hardware:

- Intel Pentium D overclocked to 4GHz with 1.45Vcore (used this as the variable load)
- Gigabyte X48T-DQ6
- 4x2GB RAM
- NVidia Geforce GT640
- 2x IDE HDD

Using a current clamp i got the following load numbers:
12V (12.09): 18.5A / 222W
5V (4.99): 5A / 25W
3.3V (3.25): 8A / 26.5W
Total power: 273.5W (~275W)

Using my PR10 power meter, i got the following numbers from the socket:
Power: 340W
Voltage: 221V
Current: 2.0A
Power Factor: 0.76
Efficiency: 275/340 = 0.81 = 81% (pretty decent, that's probably 220VAC doing it's magic)

Temperature wise, the power supply could probably use a bigger secondary heatsink, the fan ramps up nicely:

60c Primary heatsink
60c Transformer
75c Secondary heatsink
80c Output inductor
PFC coil: Toasty

I can call it a win this time.

[goodpsusearch]

Re: the gutless, bloated, and fried power supply hall of shame

Force DR-8460BTX (MAX 450W) v2.2

The fan stopped but the psu continued working till it almost burnt itself to death.

[PeteS in CA]

Re: the gutless, bloated, and fried power supply hall of shame

Deer DR-8500BTX (MAX 500W)

not able to output any watts in specs here

Might do 200-250W, but if those "Y caps" are generic 1KV or 2KV DC parts instead of agency-approved safety caps, .

[Hemingray]

Re: the gutless, bloated, and fried power supply hall of shame

Deer DR-8500BTX (MAX 500W)

not able to output any watts in specs here

These crapbox PSUs still exist in 2020?

[Dan81]

Re: the gutless, bloated, and fried power supply hall of shame

At least the case is still useable tho.

If it has standard mounting spaces (some older variants of that case had the mounting holes spaced a bit different so that it wouldn't screw an different board), you could fit any good PSU that has low-height heatsinks and primary caps. IIRC I managed to fit a beefy KME PCB in a dead Allied casing (that had a 12cm fan). Had to remove the PFC completely though.

[bauto601]

Re: the gutless, bloated, and fried power supply hall of shame

Deer DR-8500BTX (MAX 500W)

not able to output any watts in specs here

I mostly just lurk around on these forums, but this unit cought my attention. That must've been a very luxurious and expensive model for Deer. I mean, they really went out of their way for this one and did all kinds of extra work to still produce a shitty PSU.

- Added a seperate PCB for input filtering
- 4 "fat" diodes for input rectifier bridge
- real output rectifiers, no "2-diodes-on-a-plate" jobby
- The caps were good enough to last for a couple of years it seems
- A label completely dedicated to this one PSU version

I mean, they even painted the case and glued the fuse down. That's some serious build quality you don't expect from a Deer unit.

[goodpsusearch]

Re: the gutless, bloated, and fried power supply hall of shame

Deer DR-8500BTX (MAX 500W)

not able to output any watts in specs here

[Dannyx]

Re: the gutless, bloated, and fried power supply hall of shame

You'd be slightly disappointed to find out there's really not much, if anything, your run of the mill thief could value from these containers - just random measuring equipment and some plumbing. I can't imagine there's too many of those on Ebay, which would instantly track you down if you posted an add for one....whatever it is, since you wouldn't even know what it does (even WE don't, since those are not covered by this maintenance contract - just the security systems)

Getting INTO the container, even with no security at all, would take a bit of time, since it's surrounded by a fairly tall fence with barbed wire at the top, so you'd have to carry ladders, wire cutters and other heavy equipment

Each container also has a backup diesel generator, a large UPS after that AND individual batteries for those supplies (along the bottom of that closet in the picture), so power cuts were also thought of when designing these....pretty bulletproof in that respect.

[ChaosLegionnaire]

Re: the gutless, bloated, and fried power supply hall of shame

You, Sir, know how to keep yourself in business, then.

Well yeah...we use whatever random brand the local electronics store carries at that time Now that's not really "professional" by any standard, but then again, what IS ? It has to be done quickly and cheaply if possible, so sourcing "good" caps would take longer and be more expensive, resulting in someone higher up complaining about why I went with the more expensive choice...

well it looks more like dannyx's bosses know how to keep themselves in business!

however, do note that such half-baked, half-assed repairs dont make the system or place any more secure. if it were me and i was a thief trying to pull an ocean's eleven heist on the place, i'd just camp out there waiting for the caps to fail again. the instant they fail and the power goes out, its time to strike! cant stop me as its a remote area, i'd be long gone by the time... wheee! its soo good! to be bad!

[Dannyx]

Re: the gutless, bloated, and fried power supply hall of shame

This is what it looks like when they're in service inside the panel (top-left) - don't think you can place your coffee mug in that orientation A fan would definitely be a good idea, but we're not really allowed to modify things too much in there, since I suggested that myself when taking up this project for the first time, but I was told it's best not to do it...besides, it keeps things running smoothly if you catch my drift

Not all of these panels are this packed: depending on where the container is located, the security systems may be more or less complex, hence more or less stuff inside the panel. This particular one is located in a "high risk" area, out in the middle of nowhere, with nobody around for miles to guard it, so it's got the most cameras, locks and sensors on it, hence the 3 supplies (+ the smaller "naked" ones in the middle of the panel). Others may have 2 or even 1 supply if it's placed in a more populated area or is guarded.

[zx8401]

Re: the gutless, bloated, and fried power supply hall of shame

Dannyx

That one looks nicely cooked :-D
Im supprised that someone didnt push the aluminium casing up against the bare metal of the shipping container, dump some of the heat maybe.
Or add a 12v pc fan to move the air across them.
But on the good side, it would keep your cup of coffee warm while working :-D.

[Dannyx]

Re: the gutless, bloated, and fried power supply hall of shame

Wait, so you used Elite and CapXon caps to fix this PSU?!
You, Sir, know how to keep yourself in business, then.
Because if the original Nichicon caps failed, then these crappy brands will fail in even shorter amount of time.

Well yeah...we use whatever random brand the local electronics store carries at that time Now that's not really "professional" by any standard, but then again, what IS ? It has to be done quickly and cheaply if possible, so sourcing "good" caps would take longer and be more expensive, resulting in someone higher up complaining about why I went with the more expensive choice...

[kevin!]

Re: the gutless, bloated, and fried power supply hall of shame

Must admit it blew my mind ever so slightly how someone on the other side of the internet, with just some random photos I provided, had a keen enough eye to pull off that sort of detective work when I who have the board in hand missed it From a factual standpoint, these containers were deployed in 2014, so you were very close, again, given the rather limited data provided - good catch

No, the pics were taken after I had already replaced it, so that is the new one (with the black top). The old one has a silver top, but I can't remember what the brand was and I already tossed it in the trash sadly...

I almost guessed it hahaha.

Exactly!
This is why I won't say those piece of crap PSUs are even capable of more than 50 Watts total. The fact that I had a Deer PSU with similar built quality (namely, 1 output cap per rail) and not able to handle a 30W TDP Pentium 3 CPU with a 5W TDP GPU (S3 Savage 4, of all things!) and a single HDD just tells me how BAD that PSU was at filtering ripple (the system would always crash under full CPU + GPU load - an issue that would always go away when I used a better quality PSU.)


Yep, MeanWell power supplies certainly DON'T belong in the gutless category here at all. But they can get fried, like any other power supply, if/when they get abused too much - which your seems to have been.

Otherwise, I consider MeanWell power supplies to be top notch - on the same level as Delta, if not better. Maybe even close to the "Astec Gods".


And now I know who exactly HASN'T been reading my PSU posts!

Yes, failed primary caps can go open-circuit, as I found like you did with much the same surprise. Namely, it's the PSU in this thread:
https://www.badcaps.net/forum/showth...hlight=Enermax

Post of interest, in particular:
https://www.badcaps.net/forum/showpo...9&postcount=10

So now, I always pull and check the primary capacitors on APFC PSUs. I'm also adding 1- 3.3uF PP metal film cap in parallel with the primary capacitor(s) as extra filtering for high ripple and to hopefully prevent pri-side silicone from blowing up, should the primary electro take a dump and go open-circuit.


Or just add proper ventilation to that PSU.

Anything that runs so hot to kill Japanese capacitors is just not well-designed. In this case, it's not the PSU, but the enclosure that it's in.


Wait, so you used Elite and CapXon caps to fix this PSU?!

You, Sir, know how to keep yourself in business, then.
Because if the original Nichicon caps failed, then these crappy brands will fail in even shorter amount of time.

Deer the worst in PSU XD.
I also don't think that 3GO is capable of maintaining stability, just by seeing that there are only very small 3 capacitors ((one capacitor per rail, except 5VSB) 5V, 3.3V, 12V) makes me want to .

MeanWell is an excellent manufacturer, I have 5 PSU of 5v, and they have an incredible build quality.

[momaka]

Re: the gutless, bloated, and fried power supply hall of shame

You may be able to deliver 150w, but surely take a terrible ripple on the voltage lines.

Exactly!
This is why I won't say those piece of crap PSUs are even capable of more than 50 Watts total. The fact that I had a Deer PSU with similar built quality (namely, 1 output cap per rail) and not able to handle a 30W TDP Pentium 3 CPU with a 5W TDP GPU (S3 Savage 4, of all things!) and a single HDD just tells me how BAD that PSU was at filtering ripple (the system would always crash under full CPU + GPU load - an issue that would always go away when I used a better quality PSU.)

This one isn't so much about a "bad" or laughable power supply by design like others, as it is about how it actually failed, since I found it rather interesting and it might actually be a first occurrence to me: this is a "MeanWell" supply

Yep, MeanWell power supplies certainly DON'T belong in the gutless category here at all. But they can get fried, like any other power supply, if/when they get abused too much - which your seems to have been.

Otherwise, I consider MeanWell power supplies to be top notch - on the same level as Delta, if not better. Maybe even close to the "Astec Gods".

I learned throughout the years from various sources that it's good practice to replace the main cap(s) whenever you've got failed transistors AND the supply tends to run hot, so without even measuring it or thinking it over too much, I replaced the main cap (150uF/400v) even though it showed no obvious signs of failure (others I did before would most often be bulged indeed). I tossed the old cap in a tray on my desk and forgot about it for a few days, since I was busy with other stuff. Today as I was sitting around doing nothing, I lay my eyes on that tray and see the cap. Pulled out my brand NEW (! ) meter and measured it mostly for fun.....nothing....no reading at all. Remember how I said the meter is new...yeah, well for a good 5 minutes I tinkered with it thinking perhaps I'm an idiot who lacks a few neurons to properly operate something as simple as a meter, until I gave up and did two things to confirm: grabbed a cap meter from a colleague and also a good known cap. Turns out I wasn't doing anything wrong: the faulty cap was indeed DEAD ! Way past dead in fact: no reading at all on either meter, not even a smidgen, so it's a good idea I replaced it. Must admit I haven't seen this happening before: a cap not giving any reading AT ALL on two different meters ? Interesting stuff...goes to show you should ALWAYS check the main caps on highly stressed supplies like these...

And now I know who exactly HASN'T been reading my PSU posts!

Yes, failed primary caps can go open-circuit, as I found like you did with much the same surprise. Namely, it's the PSU in this thread:
https://www.badcaps.net/forum/showth...hlight=Enermax

Post of interest, in particular:
https://www.badcaps.net/forum/showpo...9&postcount=10

So now, I always pull and check the primary capacitors on APFC PSUs. I'm also adding 1- 3.3uF PP metal film cap in parallel with the primary capacitor(s) as extra filtering for high ripple and to hopefully prevent pri-side silicone from blowing up, should the primary electro take a dump and go open-circuit.

I noticed that the output caps are Nichicon HE, which is a very good series, generally. However they use a water-based electrolyte, which do less well than non-aqueous solvent-based electrolytes with heat. If the output caps are frequent-fryers I'd suggest trying Nichicon's PA series, if it's available to you. The impedance is almost identical to the HE series but it's not a water-based electrolyte.

Or just add proper ventilation to that PSU.

Anything that runs so hot to kill Japanese capacitors is just not well-designed. In this case, it's not the PSU, but the enclosure that it's in.

No, the pics were taken after I had already replaced it, so that is the new one (with the black top). The old one has a silver top, but I can't remember what the brand was and I already tossed it in the trash sadly...

Wait, so you used Elite and CapXon caps to fix this PSU?!

You, Sir, know how to keep yourself in business, then.
Because if the original Nichicon caps failed, then these crappy brands will fail in even shorter amount of time.

[Dannyx]

Re: the gutless, bloated, and fried power supply hall of shame

Seeing the date of the PCB, if it has been installed at least since 2012 or 2013 it will have at least 60,000h, I think it is normal for the capacitor to evaporate the electrolytic content and more if it is in a very hot environment.

Must admit it blew my mind ever so slightly how someone on the other side of the internet, with just some random photos I provided, had a keen enough eye to pull off that sort of detective work when I who have the board in hand missed it From a factual standpoint, these containers were deployed in 2014, so you were very close, again, given the rather limited data provided - good catch

The capacitor that failed was the elite brand that is in the photo?

No, the pics were taken after I had already replaced it, so that is the new one (with the black top). The old one has a silver top, but I can't remember what the brand was and I already tossed it in the trash sadly...

[PeteS in CA]

Re: the gutless, bloated, and fried power supply hall of shame

Here's another long story of mine
...
We were told that only a few cameras were still operational there (they're remotely accessible from a head office) and that the gate for the outer fence and also the door of the container itself wouldn't open by means of the RFID access cards these chaps use to get in/out, so we went down to investigate and got in using the regular key. There's 3 of these supplies side-by-side inside a control panel, making it a pretty hot environment in there. These things get.....hot...VERY hot - you can barely hold your hand on the metal casing, so they fail fairly often. I've fixed like 4 of them in 1 month. The most common issue is faulty caps of course, which in the case of these particular supplies most often resulted in the supply failing to turn on intermittently, ...

I noticed that the output caps are Nichicon HE, which is a very good series, generally. However they use a water-based electrolyte, which do less well than non-aqueous solvent-based electrolytes with heat. If the output caps are frequent-fryers I'd suggest trying Nichicon's PA series, if it's available to you. The impedance is almost identical to the HE series but it's not a water-based electrolyte.

[kevin!]

Re: the gutless, bloated, and fried power supply hall of shame

Here's another long story of mine

This one isn't so much about a "bad" or laughable power supply by design like others, as it is about how it actually failed, since I found it rather interesting and it might actually be a first occurrence to me: this is a "MeanWell" supply that powers several CCTV cameras and electromagnetic locks (the combination is pretty unusual) at a small shipping container somewhere in the middle of a field/nowhere which houses various equipment for gathering data about residual waters in the area, but that's beside the point.

We were told that only a few cameras were still operational there (they're remotely accessible from a head office) and that the gate for the outer fence and also the door of the container itself wouldn't open by means of the RFID access cards these chaps use to get in/out, so we went down to investigate and got in using the regular key. There's 3 of these supplies side-by-side inside a control panel, making it a pretty hot environment in there. These things get.....hot...VERY hot - you can barely hold your hand on the metal casing, so they fail fairly often. I've fixed like 4 of them in 1 month. The most common issue is faulty caps of course, which in the case of these particular supplies most often resulted in the supply failing to turn on intermittently, accompanied by the random clicking of the output relay for the SLA backup battery, since I forgot to mention these are "backup" PSUs which have a terminal for connecting a SLA in parallel to the output which basically kicks in when the SMPS shuts off, so there's a relay inline with the battery that prevents it from being connected to the output immediately, unless the SMPS has powered on at least once to pull the contacts of the relay together. At the far side of the output screw block you can just about make out a white header: if you shunt its pins, that sends the battery's own voltage to the coil of the relay so you can turn on the output on battery even without mains present.

The power LED was indeed off on this one, so it was totally dead. I shunted that header with a screwdriver just to ensure the devices reported as non functional still power on fine once they get their power, which they did. I took the PSU out of the panel, replaced it with an identical functional one we always carry around as a backup to keep things running nice and smoothly and brought it back to the store. Popped the cover off and immediately noticed a blown and darkened fuse, so I knew an important semiconductor must've popped: the bridge rectifier, the PFC transistor, the diode or the main transistor, there's 1 of each.

Sure enough, the PFC transistor was shorted (2SK3903, already removed in the pics). Other components around it like diodes and resistors seem to be fine. Now that itself is not very interesting - transistors do fail out of the blue like that when their time is up, but this one had an underlying cause: I learned throughout the years from various sources that it's good practice to replace the main cap(s) whenever you've got failed transistors AND the supply tends to run hot, so without even measuring it or thinking it over too much, I replaced the main cap (150uF/400v) even though it showed no obvious signs of failure (others I did before would most often be bulged indeed). I tossed the old cap in a tray on my desk and forgot about it for a few days, since I was busy with other stuff. Today as I was sitting around doing nothing, I lay my eyes on that tray and see the cap. Pulled out my brand NEW (! ) meter and measured it mostly for fun.....nothing....no reading at all. Remember how I said the meter is new...yeah, well for a good 5 minutes I tinkered with it thinking perhaps I'm an idiot who lacks a few neurons to properly operate something as simple as a meter, until I gave up and did two things to confirm: grabbed a cap meter from a colleague and also a good known cap. Turns out I wasn't doing anything wrong: the faulty cap was indeed DEAD ! Way past dead in fact: no reading at all on either meter, not even a smidgen, so it's a good idea I replaced it. Must admit I haven't seen this happening before: a cap not giving any reading AT ALL on two different meters ? Interesting stuff...goes to show you should ALWAYS check the main caps on highly stressed supplies like these...

Seeing the date of the PCB, if it has been installed at least since 2012 or 2013 it will have at least 60,000h, I think it is normal for the capacitor to evaporate the electrolytic content and more if it is in a very hot environment.
Exactly on my acer g225hq screen that I have, the same thing happened, and that is where I am writing this message, (PD: I took it out of a supermarket that replaced the screen because it broke down, and it will have more than 40,000h of use), the monitor did not start, all capacitors were visually seen in good condition, and I thought that the electrolytic may have dried up, and logically replace all the capacitors that were right next to the transistors heat sinks, when removing one of them, I went to measure it, and it marked a very low capacitance (the capacitor had an original capacity of 2200 microfarads and in the tester it marked 500 microfarads).
I replaced all the capacitors and the monitor came back to life, and 7 months later it continues to provide service .
In short, you never have to rely on the visual state, sometimes the electrolytic evaporates and there are no signs of wear.
And it can happen that there is no reading, if the condenser dries, there is no contact on the plates with the cathode and anode internally, since there is no contact it is not possible to check its capacity.
one of its legs that connects to the plates may also have broken.
The capacitor that failed was the elite brand that is in the photo?
the capacitors on my screen were also elite ...
From what I see they do not tolerate heat and tend to dry.

[Dannyx]

Re: the gutless, bloated, and fried power supply hall of shame

Here's another long story of mine

This one isn't so much about a "bad" or laughable power supply by design like others, as it is about how it actually failed, since I found it rather interesting and it might actually be a first occurrence to me: this is a "MeanWell" supply that powers several CCTV cameras and electromagnetic locks (the combination is pretty unusual) at a small shipping container somewhere in the middle of a field/nowhere which houses various equipment for gathering data about residual waters in the area, but that's beside the point.

We were told that only a few cameras were still operational there (they're remotely accessible from a head office) and that the gate for the outer fence and also the door of the container itself wouldn't open by means of the RFID access cards these chaps use to get in/out, so we went down to investigate and got in using the regular key. There's 3 of these supplies side-by-side inside a control panel, making it a pretty hot environment in there. These things get.....hot...VERY hot - you can barely hold your hand on the metal casing, so they fail fairly often. I've fixed like 4 of them in 1 month. The most common issue is faulty caps of course, which in the case of these particular supplies most often resulted in the supply failing to turn on intermittently, accompanied by the random clicking of the output relay for the SLA backup battery, since I forgot to mention these are "backup" PSUs which have a terminal for connecting a SLA in parallel to the output which basically kicks in when the SMPS shuts off, so there's a relay inline with the battery that prevents it from being connected to the output immediately, unless the SMPS has powered on at least once to pull the contacts of the relay together. At the far side of the output screw block you can just about make out a white header: if you shunt its pins, that sends the battery's own voltage to the coil of the relay so you can turn on the output on battery even without mains present.

The power LED was indeed off on this one, so it was totally dead. I shunted that header with a screwdriver just to ensure the devices reported as non functional still power on fine once they get their power, which they did. I took the PSU out of the panel, replaced it with an identical functional one we always carry around as a backup to keep things running nice and smoothly and brought it back to the store. Popped the cover off and immediately noticed a blown and darkened fuse, so I knew an important semiconductor must've popped: the bridge rectifier, the PFC transistor, the diode or the main transistor, there's 1 of each.

Sure enough, the PFC transistor was shorted (2SK3903, already removed in the pics). Other components around it like diodes and resistors seem to be fine. Now that itself is not very interesting - transistors do fail out of the blue like that when their time is up, but this one had an underlying cause: I learned throughout the years from various sources that it's good practice to replace the main cap(s) whenever you've got failed transistors AND the supply tends to run hot, so without even measuring it or thinking it over too much, I replaced the main cap (150uF/400v) even though it showed no obvious signs of failure (others I did before would most often be bulged indeed). I tossed the old cap in a tray on my desk and forgot about it for a few days, since I was busy with other stuff. Today as I was sitting around doing nothing, I lay my eyes on that tray and see the cap. Pulled out my brand NEW (! ) meter and measured it mostly for fun.....nothing....no reading at all. Remember how I said the meter is new...yeah, well for a good 5 minutes I tinkered with it thinking perhaps I'm an idiot who lacks a few neurons to properly operate something as simple as a meter, until I gave up and did two things to confirm: grabbed a cap meter from a colleague and also a good known cap. Turns out I wasn't doing anything wrong: the faulty cap was indeed DEAD ! Way past dead in fact: no reading at all on either meter, not even a smidgen, so it's a good idea I replaced it. Must admit I haven't seen this happening before: a cap not giving any reading AT ALL on two different meters ? Interesting stuff...goes to show you should ALWAYS check the main caps on highly stressed supplies like these...

[kevin!]

Re: the gutless, bloated, and fried power supply hall of shame

If that thing is identical to the L-LINK you linked, it's basically a 150W power supply. I doubt the main transformer core is good for 200W, and those input electrolytics might have decent filtering and hold-up for 200W.

It is the same PCB model, although I noticed that in the core of the transformer that carries the 3GO puts ERL35 (although I doubt it is true, it is too small to be an ERL35, I think it is rather 28 same as the L-LINK ), and has a small PFC winding and an X2 capacitor (in the area where RX1 is written in the L-LINK PSU), but the rest is the same, even the model is the same (zf-2012b) except the REV which is VER2.0 the L-LINK and the 3GO VER2.1.
And I realized that it has tin balls stuck in some components.
Then I will put more detailed photos inside the PSU.
You may be able to deliver 150w, but surely take a terrible ripple on the voltage lines.