Annoying heavy load-failure in Tecnoware Free Silent 500W

[Behemot]

Re: Annoying heavy load-failure in Tecnoware Free Silent 500W

Won't hurt. The pads should be firm though, not any pasty stuff, in such case they are bad as they won't properly insulate.

[omega]

Re: Annoying heavy load-failure in Tecnoware Free Silent 500W

I have noticed that in that PSU the diodes (as well as the choppers) have been in contact to the heatsink through sort of pink gummy layer, without using any thermal paste. In the replacement of the diode, should I put some white paste between the back side of the diode and the gummy film?

[Behemot]

Re: Annoying heavy load-failure in Tecnoware Free Silent 500W

Could still buy those in there and caps from me

[momaka]

Re: Annoying heavy load-failure in Tecnoware Free Silent 500W

I bet no matter what editing you do, it'll still be at least 2 times as expensive as my stock, incl. shipping…

Yeah, it's possible. But I think he's doing it because of the MBR40L60CTG rectifiers.

[Behemot]

Re: Annoying heavy load-failure in Tecnoware Free Silent 500W

I edited my order draft to RS, by replacing caps which did not fit those series. I guess that the low impedance/ESR (are they synonymous?) which is not reported, has somewhat to do with ripple current (reported): the more, the better!

I bet no matter what editing you do, it'll still be at least 2 times as expensive as my stock, incl. shipping…

[momaka]

Re: Annoying heavy load-failure in Tecnoware Free Silent 500W

I guess that the low impedance/ESR (are they synonymous?)

More or less, yes.
If I remember correctly, ESR and impedance are equal usually at 100 KHz frequency, or something like that. Beyond that, they are very similar, but not quite the same.

You are wrong here: it is a SF2004PT 20 A fast-recovery (not Schottky however).

Ah yes, you did mention that in post #15. I just forgot

You are right. That resistor connects -12 to +5 rails. I will remove it, but I do hope the PSU so heavy modified will not eventually explode because of its possible critic points

It should be okay. That load resistor is there to provide some load on the -12V rail so that it doesn't go too high. But most of the time, it won't - even with the other PSU rails loaded. I guess just measure the voltage once you are done fixing the PSU. If it goes above -13.2V, then you might need a load resistor - in that case, something like 510-680 Ohms might be more reasonable. 1-2 Watt resistor will do. But if the -12V rail stays within -10.8 to -13.2 Volts, then no need for a resistor.

No, I haven't touched the originally designed PSU, so far.

What do you suggest me to fix possible component vibrations? Hot glue or whatever?

No, that's not necessary.

I was just wondering why there is an empty spot for a fan header. But I think I figured it out, now. Probably the manufacturer had originally designed the PSU to have an external fan controller and get power from -12V and 5V rails.

A happy New Year to you and the forum!

Thanks!
Happy new year to you and the people around you as well

[omega]

Re: Annoying heavy load-failure in Tecnoware Free Silent 500W

Dear Momaka,
thanks for your very informative reply!

If RS does list the series, look for these:
Manufacturer.................Series
Nichicon ................................ PW, PM, PS, PJ, PV, HE, HD, HW
United Chemicon (UCC) ............ KY, KYA, KYB, KZE, LXV, LXY, LXZ, KZH, KZM
Panasonic .............................. FC, FK, HFQ (old stock only), FR, FM
Samxon ................................. RS
Rubycon ................................ YXJ, YXG, ZL, ZLJ, ZLK

I edited my order draft to RS, by replacing caps which did not fit those series. I guess that the low impedance/ESR (are they synonymous?) which is not reported, has somewhat to do with ripple current (reported): the more, the better!

Just the 12 V rail, which I think even the FAL500DF2 PSUs probably use a 16 A fast-recovery rectifier.

You are wrong here: it is a SF2004PT 20 A fast-recovery (not Schottky however). Anyway, the right Schottky (I chose MBR40L60CTG) only costs 1 € each, it is not worth of replacing with a used one.

The 110 Ohm resistor (color code: brown, brown, brown, gold?) appears to be connected between -12 V rail and 5 V rail. But can you verify this? If this is true, then it will be dissipating close to 2.6 Watts, which is way too much. I will wait for you to confirm, but if true, I suggest you remove that resistor.

You are right. That resistor connects -12 to +5 rails. I will remove it, but I do hope the PSU so heavy modified will not eventually explode because of its possible critic points

There also appears to a unpopulated fan header spot on the PCB between small coil and 5 VSB purple wire. Was there anything in that spot at all originally?

No, I haven't touched the originally designed PSU, so far.

What do you suggest me to fix possible component vibrations? Hot glue or whatever?

A happy New Year to you and the forum!

[momaka]

Re: Annoying heavy load-failure in Tecnoware Free Silent 500W

In choosing Nichicon caps on RS, I discovered that there no apparent indication of ESR value. On the other hand, lifetime at 105 °C is indicated. I do hope 1000-2000 hours is not too little.

Do you know what series they were? Nichicon usually uses a 2-letter name, like for example VR, VZ, HM, HN, etc.

If RS does list the series, look for these:
Manufacturer.................Series
Nichicon ................................ PW, PM, PS, PJ, PV, HE, HD, HW
United Chemicon (UCC) ............ KY, KYA, KYB, KZE, LXV, LXY, LXZ, KZH, KZM
Panasonic .............................. FC, FK, HFQ (old stock only), FR, FM
Samxon ................................. RS
Rubycon ................................ YXJ, YXG, ZL, ZLJ, ZLK

That's not feasible, because old diodes are much bigger and different pitch

It is possible, - you can bend the leads... BUT, there's not much point in upgrading the 3.3 V and 5 V rail rectifiers. Just the 12 V rail, which I think even the FAL500DF2 PSUs probably use a 16 A fast-recovery rectifier.

I attached the pics you requested, including that of the fan and the specifications in the case of the PSU for your reference. In the first pic you can also see the black wires of sort of sensor which lies inside the right coil.

Ah, okay. So the fan has a thermal "controller" (well, sort of - this is just a really cheap and "dirty" way to it). The "sensor" in the coil is probably a NTC thermistor - as the surface of the coil gets hot, it heats the NTC thermistor as well. As the NTC thermistor heats up, its resistance drops and makes the fan spin faster.
^ That's in theory, though. In reality, as the fan draws current through the thermistor, the thermistor heats up, which makes it let more current through which makes it heat even faster until the fan is spinning near full speed. So it probably isn't doing to much to regulate the fan speed, but I think we can leave it alone for the time being.

In facts, between the two coils (see pic) there are two uncommon 1W resistors, that's 110 [?] and 51 [?] ohm, respectively (the latter is invisible in the pic).

Yup, that's two of the load resistors.

The 51 Ohm resistor (color code: green, brown, black, gold) appears to be for the 5 V rail. That means, it is dissipating around 0.5 Watts, which is not too bad.

The 110 Ohm resistor (color code: brown, brown, brown, gold?) appears to be connected between -12 V rail and 5 V rail. But can you verify this? If this is true, then it will be dissipating close to 2.6 Watts, which is way too much. I will wait for you to confirm, but if true, I suggest you remove that resistor.

There also appears to a unpopulated fan header spot on the PCB between small coil and 5 VSB purple wire. Was there anything in that spot at all originally?

Yes I get a box full. But as you saw, unfortunately I have cut all wires and disposed all the cases and restoring them now maybe would be not worth of.

Well, keep them for now. Maybe even open a new thread for those PSUs and try to see what the problem is?

If in the future you get more crappy PSUs (but with 80 mm fans), you can put these old PSUs in their cases and solder the wires from the crappy PSUs on these PSUs. Then you are back in business

[mockingbird]

Re: Annoying heavy load-failure in Tecnoware Free Silent 500W

Be careful with those ASUS items.

I have experience with the board he's using - the P5B - as I use it myself...

omega - you should certainly replace the at least the VRM high capacitors which are most certainly KZG on this particular board, as well as the Toshin Kyogo capacitors scattered throughout the board.

It's a very capable motherboard, even today.

[omega]

Re: Annoying heavy load-failure in Tecnoware Free Silent 500W

In choosing Nichicon caps on RS, I discovered that there no apparent indication of ESR value. On the other hand, lifetime at 105 °C is indicated. I do hope 1000-2000 hours is not too little.

You can at least take the silicon from them and upgrade the others ones with it…

That's not feasible, because old diodes are much bigger and different pitch

[Behemot]

Re: Annoying heavy load-failure in Tecnoware Free Silent 500W

You can at least take the silicon from them and upgrade the others ones with it…

[omega]

Re: Annoying heavy load-failure in Tecnoware Free Silent 500W

I attached the pics you requested, including that of the fan and the specifications in the case of the PSU for your reference. In the first pic you can also see the black wires of sort of sensor which lies inside the right coil.

However, a picture of the underside (solder side) and another of the secondary side caps from up top could help too. I think there may be large "dummy" load resistors on the secondary of your PSU, and those like to run very hot sometimes (but it depends on what the PSU manufacturer chose). If they do run hot, it may be a good idea to remove them. I do that with my Deer/L&C PSUs all the time, because the hot dummy load resistors in those cook the caps.

In facts, between the two coils (see pic) there are two uncommon 1W resistors, that's 110 [?] and 51 [?] ohm, respectively (the latter is invisible in the pic). There is a slot in in the PCB in correspondence of the two resistors (to dissipate heat?), so I guess these are load ones, right?

See edited picture I attached:

That's fine, thanks. I am beginning to understand better the meanings of the different rails.

Finally, make sure the PSU fan is NOT wired directly to 12V, because cheap PSUs often use cheap fans that like to die quickly when wired to 12V directly (which happens in at least 90% of cheap PSUs). There are a few different ways to lower the voltage on the fans, but I will wait until you post a picture of the bottom side and the secondary side from up top to see what is there.

Sorry I don't understand what you mean. One 12 cm 12 V brushless fan (see pic) is plugged in the socket in the right bottom of the cap pic.

Be careful with those ASUS items.

You are right! Over these years I experienced lots of Chemicon KZG 6.3 V 820 uF cap failures, most of which have been in the southbridge. By replacing them with Panasonic good ones, I saved all mobos except two. Failures also in the graphic card (same damn cap) have been fixed. Incidentally, replacing those caps has been the divide between my passive (i.e. user) and active (i.e. amateur fixer) use of the machines.
But I did not replace all caps, just wait some get bulged and replace them.

Do you still have all of those broken FAL500DF2 PSUs? - at least the boards (I am assuming you do, since you did take a picture of it). If yes, it may be worthwhile to try and repair some of these and place them in the cases of the of the FAL501FS12 units. I am looking at the pictures, and they look a lot more promising.

Yes I get a box full. But as you saw, unfortunately I have cut all wires and disposed all the cases and restoring them now maybe would be not worth of.

[Behemot]

Re: Annoying heavy load-failure in Tecnoware Free Silent 500W

In my experience, a single schottky diode will usually have about the same or lower voltage drop (Vf) than two fast recovery rectifiers in parallel

That's exactly my point. If you add half a volt, it may be OK under heavier +12 V load, but in idle the unit may get crazy because it will be too much for the feedback…

[momaka]

Re: Annoying heavy load-failure in Tecnoware Free Silent 500W

I would suggest, if there are parallel positions, to use two of those F16C20CT rectifiers instead of single schottky. Because single schottky could bring the voltage too much higher which will make problems with regulation…

In my experience, a single schottky diode will usually have about the same or lower voltage drop (Vf) than two fast recovery rectifiers in parallel, so I think it would be a lot better to use the schottky. It does depend a lot on what schottky you get, though. Some have large forward voltage drop - almost as much as the FRs. The three schottky rectifiers I suggested are decent, especially the MBR40L60CT, which will have about 0.5V Vf at 10 A per diode leg - IMO, that's quite an improvement over the F16C20CT. Even the STPS20S100CT will have about 0.6V Vf at 10 A. Compare that to two F16C20CT in parallel, which will still have about 0.85V Vf each at 5 A per diode leg.

Anyway, the modification you are proposing me is the replacement of the TO220 12V rail double diode (sorry no parallel positions), and the caps with those of bigger capacity. Right?

Yes, exactly!

Here the HR pics of the PSU you requested me.

Excellent pictures! I think that will do for now. However, a picture of the underside (solder side) and another of the secondary side caps from up top could help too. I think there may be large "dummy" load resistors on the secondary of your PSU, and those like to run very hot sometimes (but it depends on what the PSU manufacturer chose). If they do run hot, it may be a good idea to remove them. I do that with my Deer/L&C PSUs all the time, because the hot dummy load resistors in those cook the caps.

But I still don't understand what cap should replace what.

See edited picture I attached:
https://www.badcaps.net/forum/attach...9&d=1451272098

* The caps with purple dots are for 5 VSB. Use two (2x) 1000 uF 6.3/10V caps with 8 mm diameter.
* The caps with orange dots are for 3.3 V rail. Use two (2x) 2200-3300 uF 6.3/10V caps with 10 mm diameter.
* The caps with red dots are for 5 V rail. Use two (2x) 2200-3300 uF 6.3/10V caps with 10 mm diameter.
* The caps with yellow dots are for 12 V rail. Use two (2x) 1500-3300 uF 16V caps with 10 mm diameter.
* The cap with blue dot (hidden behind 12V rail caps) is for -12 V rail. Use one (1x) 470-1000 uF 16V cap here.
* The caps with green dots are for BJT (chopper transistors) drive circuit. Use same voltage and capacitance as originals. Just make sure they are of high quality, like the caps above.

I don't see a "critical" 5 VSB cap on the primary side, so that is good. However, the caps around the PWM controller (SDC 2921) may be important too (I labeled them with Cyan dots). I see only four of them, so why not replace them anyways - especially the one with the double cyan dots.

With those caps and the new 12V rectifier, I think the PSU should be fairly decent for a C2Q system. Hopefully the "Rumlcon" caps on the primary are not too bad, because with that name, I can only assume they are Rubycon look-alikes.

Finally, make sure the PSU fan is NOT wired directly to 12V, because cheap PSUs often use cheap fans that like to die quickly when wired to 12V directly (which happens in at least 90% of cheap PSUs). There are a few different ways to lower the voltage on the fans, but I will wait until you post a picture of the bottom side and the secondary side from up top to see what is there.

Mobos have been anyway Asus P5B "Vanilla", and the machines have been equipped with four 2GB DDR3 banks, one physical SATA HDD 7200 rpm for each core, one DVD burner and one 3.5'' disk drive. Since they had to do MPI numerical computation only, graphic cards (in the PCIEX16 slot) were unimportant and cheap (ASUS EN-6200-LE).

Be careful with those ASUS items.

Both the motherboards and the video cards may have Chemicon KZG caps (brown caps with a "Y" vent on top). The KZG series from Chemicon is know to fail quite A LOT, especially with high heat. I suggest you inspect all motherboards and video cards.

Better yet, if you want piece of mind, it might be worthwhile to replace those KZG caps too, while you are at it. Now, I know I keep adding things for you to do - sorry for that. But I just really want to make sure you are aware of what you are dealing with, in case more issues appear in the future, be it from the motherboards or the graphics cards. Speaking of the graphics cards, the EN-6200-LE appear to be a passively-cooled. If you do ever get a PC with a "no video output" problem, the graphics card could well be the issue. Reason being is that the GeForce 6x00 series tend to break much faster when heated above 60C, and with a passive radiator, those EN-6200-LE cards may be reaching that temperature.

For your reference, here are the four side pics of the old Tecnoware FAL500DF2. Moreover, what you cannot see in the pics: 2x SC2625 as choppers and 2x S30D40C + 1x SF2004PT as double diodes.
In 2010 I dismissed many of them, in retrospective I think it was unwise not to repair instead of replacing them with new wares. But everyone has to learn based on his/her own errors.

Yup, those older FAL500DF2 units were indeed much better built. Looks like CWT with those green transformers, but I could be wrong.

Do you still have all of those broken FAL500DF2 PSUs? - at least the boards (I am assuming you do, since you did take a picture of it). If yes, it may be worthwhile to try and repair some of these and place them in the cases of the of the FAL501FS12 units. I am looking at the pictures, and they look a lot more promising.

[omega]

Re: Annoying heavy load-failure in Tecnoware Free Silent 500W

For your reference, here are the four side pics of the old Tecnoware FAL500DF2. Moreover, what you cannot see in the pics: 2x SC2625 as choppers and 2x S30D40C + 1x SF2004PT as double diodes.
In 2010 I dismissed many of them, in retrospective I think it was unwise not to repair instead of replacing them with new wares. But everyone has to learn based on his/her own errors.

[omega]

Re: Annoying heavy load-failure in Tecnoware Free Silent 500W

Here the HR pics of the PSU you requested me.
Some years ago, I have assembled a computer rack with 15 among Dual Core Duo/Quad machines (44 cores). Mobos have been anyway Asus P5B "Vanilla", and the machines have been equipped with four 2GB DDR3 banks, one physical SATA HDD 7200 rpm for each core, one DVD burner and one 3.5'' disk drive. Since they had to do MPI numerical computation only, graphic cards (in the PCIEX16 slot) were unimportant and cheap (ASUS EN-6200-LE).
Then I choose robust, double fan Tecnoware FAL500DF2 500W PSUs (I will show it in a next post to try to convince you it was a good example of entry level PSU), but with time, those PSU had been failed and had to replace them, blind trusting in the brand and not noticing that in the meanwhile production has been transferred to China and the quality, including weight, had been reduced (FAL501FS12). For isntance, cap-sized inductors in the secondary circuit have disappeared from the PSU. But when I realised it, it was too late to come back.
Anyway, the modification you are proposing me is the replacement of the TO220 12V rail double diode (sorry no parallel positions), and the caps with those of bigger capacity. Right? But I still don't understand what cap should replace what.
I still wait for you in order to arrange a definitive improvement project to buy the components.

[Th3_uN1Qu3]

Re: Annoying heavy load-failure in Tecnoware Free Silent 500W

That is an old, 3.3/5v heavy design running a new, 12v-heavy computer. If anything, the 12v rail will be very low. Replacing the fast recovery diode with a schottky will be no problem, and is actually recommended.

[Behemot]

Re: Annoying heavy load-failure in Tecnoware Free Silent 500W

Yeah if you need some caps I can provide you, just got some new, all dirty cheap…much more than from those big ass resellers.

If you'll need some beefier silicon or bigger second-hand 200V caps, Pi coils, I should have lots of those from disposed PSUs…I would suggest, if there are parallel positions, to use two of those F16C20CT rectifiers instead of single schottky. Because single schottky could bring the voltage too much higher which will make problems with regulation…with two rectifiers, if both are really same, you should be able to get about 250 W fine with still better efficiency tha before…

[momaka]

Re: Annoying heavy load-failure in Tecnoware Free Silent 500W

You are welcome

hot side: one C5027 and two KSH13009

A little better than I expected - at least the two KSH13009, that is. They are slightly better than the standard 13007's used in cheap power supplies. With those, your PSU may be able to handle up to 300-350 Watts if the rest of it is designed right, which should be enough for a Core 2 Quad CPU. I also see the big 200V capacitors on the hot side are 560 uF, which is good.

Now do the computers you are working on have a dedicated graphics card in the PCI-E slot?

secondary side: one F16C20CT and two SBL2040CT.
Therefore if I am right, there are one 16A and two 20A Schottky diodes, that's slight better than you have foreseen.

Indeed.
The two SBL2040CT schottky diodes are okay - they are for the 3.3V and 5V rails, which are not used much in modern PC. So you don't need to worry about these.

The F16C20CT is what needs to be upgraded, because this is what is used for the 12V rail. Ideally, you should buy a schottky-type rectifier rated for at least 60V and 20 Amps or more. Something like STPS20S100CT, MBR40L60CT, or MBR2060CT would work great (there are many more choices, though). Again, look for schottky -type rectifiers only. The F16C20CT is a fast recovery -type rectifier and has a much higher voltage drop, which means higher losses in the PSU, more heat, and lower output voltages (not desirable).

As regards caps, they all are China quality (ChengX), but I had to count only 4x 1500 uF/10 V, 2x 1500 uF/16 V, 1x 470 uF/16 V, 2x 47 uF/50 V, 2x 1 uF/50 V (11 caps) in the secondary side (so no 2200 uF cap).

Well, the capacities are not as bad as I expected either. But still, you should consider getting the 2200 uF and 1500 uF capacitors I mentioned in my last post.

I still got troubles in finding in my town japanese quality caps, but i will try requesting them in North Italy once we will be arranging a complete list of them.

You would probably need to get your capacitors online from a reputable seller.
I think RS Components, Farnell/Element 14, and Newark are some of the online joints that serve Europe. You may also contact member Behemot here - he sells caps too, and he is based in Czech Republic. If you do contact him, ask if he still has the 10 mm Samxon RS 16v 3300 uF, as those would be ideal for the 12V rail of your PSUs. If not, I think he has some Chemicon 16V 2200 uF caps in 10 mm diameter as well.

Ready to give you other pieces of info at your request!

Please do.
It will really help to find what else might need to be modified or upgraded in this power supply to make it run safer/better.

[omega]

Re: Annoying heavy load-failure in Tecnoware Free Silent 500W

Dear momaka,
thanks so much for your support and sorry for the delay in answering you.
Your last message has been very impressive to me!
I have been taking some pics of the PSU and will be posting in a short time.
The semiconductors on the radiators are following:
hot side: one C5027 and two KSH13009
secondary side: one F16C20CT and two SBL2040CT.
Therefore if I am right, there are one 16A and two 20A Schottky diodes, that's slight better than you have foreseen.
The PWM chip is a China one (SDC 2921).
As regards caps, they all are China quality (ChengX), but I had to count only 4x 1500 uF/10 V, 2x 1500 uF/16 V, 1x 470 uF/16 V, 2x 47 uF/50 V, 2x 1 uF/50 V (11 caps) in the secondary side (so no 2200 uF cap).
I still got troubles in finding in my town japanese quality caps, but i will try requesting them in North Italy once we will be arranging a complete list of them.
Ready to give you other pieces of info at your request!
Best regards