Post your worthless and/or pointless repairs

[momaka]

I'm sure we've all done at least one of these before: a repair that took more effort, time, and money in parts than the device itself was worth. But you did it anyways, just for fun or because you wanted to prove that it can be done.

Also, this can be a neat repair or a ghetto one too (I know the ghetto mod thread covers that territory, but I always feel that thread it is more for showing off ghetto mods rather than complete repairs.)

Feel free to post anything here and not just computer parts or electronics. Maybe you found a chair on the street, took it home, and fixed it just as spare patio furniture?

So what's the point of this thread?
- I figured it might be good for those repairs that may still be worth posting but not really worth enough to have their own thread (like the PS3 fan repair thread I just made).

On that note, I have a feeling I will be the sole player here… but I guess that is better than me spamming badcaps.net with a dozen of new threads.

[momaka]

I guess I will lead the way here with another not-so-worthwhile-but-still-fun repair. Probably crossing way over into ghetto territory… but who cares.

Story:
I came home one day late last Fall and pushed the power button on my main computer (the venerable Dell OptiPlex 170L) to turn it ON. Then I went downstairs to get my water bottle refilled. When I come back, I see the computer hung at boot with the classic message “No Boot Device Found. Press any Key to Reboot the Machine”.

First thing that comes to my mind, great! The must HDD must have bit the dust. While I do have multiple backups of my files on multiple PCs, they are not always completely up to date as I do them whenever I have time. Thus, this would have been an inconvenience.

But then I noticed the LED light on the CD-RW/DVD-ROM combo drive was stuck ON. I turned OFF the PC and turned it back ON again. The CD-RW/DVD-ROM LED came on instantly. Pressing the eject button on it did nothing. Meanwhile, the HDD made its normal spin-up and seek sound. After a few moments, I got the same boot error again.

So I tore the computer open (after 30 minutes of removing stuff and digging it out from my “computer skyscraper” structure ) and disconnected the optical drive. Then I connected the PC to my test monitor and keyboard and fired away. Sure enough, the PC booted right into Windows.

With the OptiPlex 170L being my main computer, I still do use the optical drive once in a while, so I needed it working. While I do have a stash of optical drives, most of them are either CD-ROM or CD-RW only and the lone DVD-RW drive I had has a white bezel on it. So rather than replace the optical drive, I just closed the drive bay with a piece of cardboard to keep the airflow going through the front-bottom of the case and have the PC back operational.

As I’ve done optical drive repairs on Xbox 360s and PS3s before (as well as a few PC optical drives too), I decided to crack this one open and see if I could figure the issue out. I was hoping maybe there would be some bad caps.

And so here is the CD-RW/DVD-ROM drive: a Hitachi-LG Data Storage (HLDS) model GCC-4482b.


Label:
http://www.badcaps.net/forum/attachm...1&d=1500859375

Upon opening it, nothing seemed obviously wrong. I reseated all connectors and tested by powering up the drive with an ATX power supply, but it was still doing the same thing with the LED. So clearly there must have been a faulty component on the PCB. Speaking of which, here are the top and bottom pictures of the PCB:
http://www.badcaps.net/forum/attachm...1&d=1500859375
http://www.badcaps.net/forum/attachm...1&d=1500859375

After seeing all of the SMD caps, I wasn’t too excited about removing them to test. The first idea that came to my mind is solder some caps in parallel to see if that eliminated the problem. To do that, I started checking how the caps are connected (i.e. which voltage rails).

While at it, I noticed a few more things: the bottom of the PCB had all kinds of test points marked on it. On the right side, I saw two test points: O3.3V and O2.5V. Measuring the voltage revealed that O2.5V was not present (just a few mV), but O3.3V was okay.

This led me to look for the regulator responsible for generating the O2.5V rail. With not that many components on the board, it only took a few moments to trace that both O2.5V and O3.3V rails were connected to IC901 (labeled 09B X01 5 1, for which I couldn’t find a datasheed). Here it is from up close
http://www.badcaps.net/forum/attachm...1&d=1500859375

Resistance/continuity measurements revealed that this IC was indeed the source of both the O3.3V and O2.5V rails. I found the caps responsible for filtering its outputs, too: C690 and C994, respectively. I soldered some caps in parallel with these, as well as the input cap for IC901 (I can’t remember which cap that was, but I think C391) in hopes that the caps were the problem. Then I connected everything back up and applied power… but same thing again: LED stuck ON and 2.5V rail reading close to zero volts.

The next logical step was to check resistance of IC901’s 2.5V output to ground. However, it was not shorted or low-resistance to ground. As such, I decided to go a bit “experimental” here and see what would happen if I inserted 2.5V from an external source without disconnecting IC901. I didn’t have an adjustable PSU bench (yeah I know, such a shame for someone that likes to troubleshoot electronics ), so what I did instead is take a diode and wire it from the 3.3V rail on my test ATX PSU to the 2.5V rail on the drive. With a diode drop of 0.6-0.7 Volts, I figured I would get about 2.6 to 2.7V. It looked like the 2.5V rail was used for the RAM cache chip, so 2.6-2.7V didn’t seem too dangerous. I also put my multimeter in series with that to measure the current, in case there is something wrong (in which case, I could immediately power down my test PSU… though I don’t suggest anyone to do rely on this method, as you can still do quite a bit of damage if something is shorted).

So I wired everything and gave the ATX PSU a quick power on. Almost surprisingly, nothing smoked. However, I did get a bit frightened as I wasn’t expecting any noise. The noise came from the tray motor as it pulled the tray closed and the drive did a disc seek. But that’s good news – it’s probably alive!

The 2.5V rail drew about 200 mA, if I remember correctly. And with my plain diode, it was actually dropping a little over 0.8V, meaning I was feeding the 2.5V rail with about 2.45V. Seemed good enough for me, so I popped the tray open and inserted an audio CD, then closed it. The CD spun and I could hear the drive start to read. – Yup, the drive was definitely alive!

With that said, I started to think how to generate the 2.5V rail inside the drive. Surely I could take a diode again and have it drop voltage from the 3.3V rail from IC901. But that didn’t look appealing to me, as I thought it might overload the 3.3V output on the regulator (and knowing that the regulator already wasn’t outputting 2.5V, that just screamed bad idea). I also knew I had a bunch of 3.3V, 1.7V, and adjustable 1117 regulators from the numerous Xbox 360 motherboards I had scrapped over the years. The adjustable regulator seemed like a better idea, as I needed around 200 mA of current and I could use the 5V rail to supply that.

Some quick power dissipation calculations revealed that with a 5V input and a 2.5V output, the regulator would be dropping 2.5V. At 200 mA, the power dissipation would be 2.5V x 0.2A = 0.5 Watts – definitely something the regulator could dissipate if mounted on a small copper pad on the PCB.

As such, I took a SOT-223 1117 adjustable regulator from my parts box and started thinking where I can place it on the board so that it could have its own small copper pad to dissipate heat while also being close to the 2.5V test point. Next day, I came up with an idea. I drew on the PCB where I needed to make cuts and decided to proceed.
http://www.badcaps.net/forum/attachm...1&d=1500859375
http://www.badcaps.net/forum/attachm...1&d=1500859375

Probably not the cleanest job I’ve ever done, but at this point I just wanted to have the drive fixed.

I scraped most of the mask off the pads I had just cut away and soldered everything into place. This is the result:


As you can see, it is just a standard 1117 adjustable regulator design with two tiny SMD resistors of equal value used as the dividers to set the output voltage. I don’t remember what value I used for these, but I think it was 1.2 KOhms or something like that. Basically, I just started pulling resistors from a scrapped Xbox 360 motherboard, and these two were the first that had an equal resistance value that seemed reasonable for the circuit.

Preliminary testing revealed that everything worked. But then I realized, the input of that regulator is probably too far away from any caps. So I did a small revision and added a 4.7 uF ceramic cap right by the input of the regulator.


Unfortunately, I couldn’t add an electrolytic cap on the input anywhere nearby as I didn’t see any space. However, I was able to conveniently place an electrolytic cap at the regulator’s output – yes, that’s the blue cap sticking out of the board like that. I know I should be ashamed here – not because of the way I mounted that cap, but because that is a crappy Jun Fu HK cap It did test okay on ESR and capacitance, though. Speaking of which, I forgot what capacitance and voltage ratings it had (most likely 100 uF, 16V).

I probably should have done this repair a little better. Not only could I have used a better cap, but I imagine some of you cringed when you saw the thin magnet/copper wires loosely running over the PCB (but patted down with hot glue ), connecting to the 5V rail and O2.5V output. (On the other hand, think of them as wires with built-in fuse protection! )

In any case, even with the crappy cap and whatnot, this CD-RW/DVD combo drive has worked out alright. I did the repair back in January and have had the optical drive installed back in my PC since then. Still works, so I can’t complain.

[diif]

Nice work and write up momaka, i do like your style.
Have you thought about one of these perhaps for bench work. ? https://www.aliexpress.com/item/Smar...724522563.html

[dmill89]

I got this stripped (no SSD, RAM, Charger, dead batt) Latitude E4200 for $20, and proceeded to throw about $100 worth of parts at it (64Gb SSD - $30, SSD Cable - $5, batt. - $20, RAM - $20, Charger - $10) to get it working, you can pick up a working one for $50-$75 on e-bay these days (in silver or black), but I really wanted a blue one (somewhat rare color for these):












And of course just about every power supply I've ever re-capped/rebuilt cost more in materials and time (if you calculate the value of that) than it was worth.

[dmill89]

... And for a slightly more "ghetto" one. This APC Back-UPS ES350 with a dead battery, I didn't have the 12V 3.5Ah battery it took but I did have a couple 6V 4.5 Ah batteries, so I hacked up the case to make room and wired them together in series. On paper the batteries cost as much as the whole UPS making the repair "worthless", but I had them laying around (from a rechargeable lantern that died) so it made sense in this case:

[eccerr0r]

Not nearly as detailed but I also had a simple obsolete 4/4/24 (IIRC) CDRW drive that was jammed (cannot read DVDs at all). Turned out the plastic on the tray was cracked due to some abuse while it was opened. I found a way to stick in a screw to jury rig the cracked plastic to work as it once was (there was a plastic guide pin... now it's a metal screw guide pin)... the tray doesn't come out/go in as fast as it used to, but it's now working as it used to, and burns CDRWs once again...

Really these CDRW drives should become IR burning lasers...

---

another pending probably pointless repair:

I have a portable flimsy-as-plastic RCA wallyworld DVD player that doesn't read media anymore. I think I rootcaused it to the reader focus mechanism somewhere but now whether to fix it I don't know...

[Per Hansson]

This is a work in progress.
I have many WRT54GS and WRT54GL routers installed at customers.
Sometimes they take a lightning strike but don't outright die.
That's when I take them over and try to resurrect them.
I had three of them in my scrap pile now.
One is 100% dead, it's from this thread: http://www.badcaps.net/forum/showpos...86&postcount=6
As you can see the WiFi chip has a hole where the magic smoke has escaped, as does the amplifier!
Oh, and the main processor is fried too, I guess this one is a bit beyond economic repair

The second was a WRT54GL, as seen in this thread it was "repaired" by a simple nvram erase.
It was just stuck at it's CFE but to do it I needed a serial console of course...

Third is the "work in progress" WRT54GS router.
I had discarded it earlier because it kernel panics when loading Linux.
And the switch chip becomes hot enough to fry bacon on, not kidding:


Well, I did some research and with the help of the nice guys on #lede-dev they suggested it's the WiFi that causes the kernel panic.
So I built a version of LEDE with the sole difference of the Broadcom B43 driver not being loaded.

With this change it loads LEDE right up and works great without WiFi!
(Of course with a big heatsink on the BCM5325EKQM switch chip).
So now I have ordered a new switch chip on Aliexpress, let's see if it arrives this year

[eccerr0r]

Would repairing Deer PSUs be considered pointless? I did that once too...and later it failed again with a different problem. I junked it then.

[stj]

yes.

infact the only really pointless repairs are the ones that fail.

[eccerr0r]

Think that first repair of that deer was tracked down to a shorted ceramic capacitor. Then a year later of it working fine, the switching transistors fried. I gave up then.

[Doc38343]

Just take a gander at pretty much any of my threads... the one that comes to mind strongest is the Magnavox Trash bin TV...... yeah .... why? why? oh why?

http://www.badcaps.net/forum/showthread.php?t=63244

[eccerr0r]

Dang I don't even own a TV like that... where can I get TVs that the only problem is that the screen's upside down...

[Doc38343]

Originally Posted by eccerr0r

Dang I don't even own a TV like that... where can I get TVs that the only problem is that the screen's upside down...

It also looks horrible, the picture is clear but the colors are out of wack bad.
After some research (and wasting $19 on a main) I now believe the guys who worked on it before me also bought a incorrect main board. I went by the numbers on the board so i also bought the wrong board. I figured this out thru the thread responses and putting the TV SERIAL number into shop jimmy search i found the board is a different number. (there are a LOT of these out there even other brands)
Then I just happened to visit my local pawn shop to see what they had and there was one same TV $40..... Meaning it was $20 higher than it should have been.. LOL (no I did not buy it)

The education I got thru the process = PRICELESS
Actual Repair = Worthless!!

[momaka]

Originally Posted by diif

Nice work and write up momaka, i do like your style.
Have you thought about one of these perhaps for bench work. ? https://www.aliexpress.com/item/Smar...724522563.html

Thanks!

Yes, I've thought about buying one (though not that one in particular, as I didn't even know it existed). But the thing is, I have an oldschool HP 6291A linear power supply from the mid-70's era. It's been on my to-do list for a few years now, but I would definitely like to fix that and use it if I can. It's supposed to be capable of 5 Amps cont., 6 Amps peak output at 40V (or if line voltage is above 115 V AC, then up to 50V output). I picked it up from a dumpster in salvage condition (missing a huge main filter cap, half the case, and a few switches and connectors). It is very heavy and quite big... so if possible to fix it, that would be great, as right now it is just a heavy door stop (more like a door barricade ). I'll probably create a thread for it some day. I like oldschool gear.

Originally Posted by dmill89

I got this stripped (no SSD, RAM, Charger, dead batt) Latitude E4200 for $20, and proceeded to throw about $100 worth of parts at it (64Gb SSD - $30, SSD Cable - $5, batt. - $20, RAM - $20, Charger - $10) to get it working, you can pick up a working one for $50-$75 on e-bay these days (in silver or black), but I really wanted a blue one (somewhat rare color for these):

Well, maybe you paid more for that laptop... but IMO, those older Dells Latitudes are always worth the investment, because they are unstoppable workhorses afterwards.

Originally Posted by dmill89

And of course just about every power supply I've ever re-capped/rebuilt cost more in materials and time (if you calculate the value of that) than it was worth.

Yeah, but you are not factoring peace of mind that you have a known good power supply that won't fail on you.
The non-PFC of PPFC Delta, HiPro, and LiteON PSUs are the best. Once recapped, they will easily go for 10 years. And more if you dust them once in a while and make sure the fan is well-oiled. I would have put Bestec in this category too, but the tan/brown conductive glue in some of these units is really hard to remove. The newer Bestec PSUs use the white silicone, though, so they are good candidates.

Originally Posted by eccerr0r

Really these CDRW drives should become IR burning lasers...

Nah, I still prefer CDs over DVDs if I can fit my data on one.

DVDs have higher data density and are much more sensitive to scratches. CDs on the other hand, can take a lot of beating before they become unreadable/coasters. Burn them at 2-8x speeds, and they are even more reliable.

Originally Posted by Per Hansson

So now I have ordered a new switch chip on Aliexpress, let's see if it arrives this year

Just wait at the seashore for the glass bottle with message and parts inside it to arrive.

Awesome repair/WIP, Per!
When I see that kind of damage (main controller, CPU, etc.), I typically give up. That said, I do have a LinkSys WRT54G v2.0 with either dead controller, RAM, and/or ethernet switch chip (the one I mentioned in your thread above). Can't say for sure, as nothing seems to overheat excessively, but I do have a low resistance reading on the 3.3V and 1.8V lines. I probably won't use it... so if you want it for parts, let me know. It's different in design and layout from the routers you posted, though.

Originally Posted by eccerr0r

Would repairing Deer PSUs be considered pointless? I did that once too...and later it failed again with a different problem. I junked it then.

Not if you learn something useful out of it. I often value knowledge more than time and money alone.

Originally Posted by stj

infact the only really pointless repairs are the ones that fail.

I suppose there is a lot of truth to that.

Originally Posted by eccerr0r

Dang I don't even own a TV like that... where can I get TVs that the only problem is that the screen's upside down...

I know, right?
Just flip the TV upside down and problem is fixed

[eccerr0r]

Originally Posted by momaka

But the thing is, I have an oldschool HP 6291A linear power supply from the mid-70's era. It's been on my to-do list for a few years now, but I would definitely like to fix that and use it if I can. It's supposed to be capable of 5 Amps cont., 6 Amps peak output at 40V (or if line voltage is above 115 V AC, then up to 50V output). I picked it up from a dumpster in salvage condition (missing a huge main filter cap, half the case, and a few switches and connectors). It is very heavy and quite big... so if possible to fix it, that would be great, as right now it is just a heavy door stop (more like a door barricade ). I'll probably create a thread for it some day. I like oldschool gear.

I also salvaged a Harrison Labs 6226A Linear PSU, except this one is missing transistors (someone bone picked it as it suffered mechanical damage). I'm not sure if I'm going to end up fixing it back up, I did fix the mechanical damage but without the transistors it's kind of pointless. It has no ICs in it, I think it uses all germanium transistors (or at least I think it does).

I was wondering if I should just throw out the guts and replace them with an IC solution, higher chance of getting this solution to "fix" it than finding schematics and the germanium transistors.

Nah, I still prefer CDs over DVDs if I can fit my data on one.

DVDs have higher data density and are much more sensitive to scratches. CDs on the other hand, can take a lot of beating before they become unreadable/coasters. Burn them at 2-8x speeds, and they are even more reliable.

I actually was thinking that using the more plentiful DVDRW drives to burn CDR/CDRWs are equally as good, really no point in using an old CDRW drive anymore. I think at most I'd use this drive as a boot medium for test computers as my DVDRW drives are all in USB enclosures and tearing them out for an IDE-only machine is annoying.

Speaking of which I have one dead DVDRW drive ... ugh... now that may end up becoming a red burning laser...

[dmill89]

Originally Posted by momaka

Just wait at the seashore for the glass bottle with message and parts inside it to arrive.

I know that feeling. I ordered a Vostok Amphibia (Dive Watch designed for the Russian military, pic below for anyone not familiar with these) from Russia and it took over 2 months to show up, and no tracking so I had not idea where it was until it finally showed up in my mailbox.

[momaka]

Okay, here is another one: a night-light / table lamp with touch-start control (i.e. you touch the metal body of the lamp to turn it ON and OFF). The repair was very simple: just had to replace a TRIAC in the lamp’s control circuit. When the TRIAC goes bad in these lamps (typically short-circuit between T1 and T2), they stay full-ON all the time and cannot be shut off unless unplugged.

Here’s the lamp I had:
http://www.badcaps.net/forum/attachm...1&d=1501046004

The control box:
http://www.badcaps.net/forum/attachm...1&d=1501046004

And here is what’s inside that box:
http://www.badcaps.net/forum/attachm...1&d=1501046004
http://www.badcaps.net/forum/attachm...1&d=1501046004

As you can see, it is not very impressive. The controller is located on the small daughterboard – not sure what it is, as it’s just a cheap COB. The TRIAC does not have any heatsink and the general layout is pretty poor, with the TRIAC’s tab touching the wires (which is NOT GOOD, because if the tab gets hot enough, it can melt through those wires). Luckily, this regulator is a series device, with only the Live going through it (Neutral goes straight to the bulb). The red and yellow wires are for the touch sensor (sorry, forgot to take picture). The white and black wires are Live input and Live output (to light bulb).

It is almost not worth the repair, as these lamps aren’t that expensive. However, this one belongs to a friend of my parents and she just asked me one day what the problem could be (she tried replacing the bulb only). She said her grand daughter liked to play with it by stepping it through the dimmable presets when she was young (this lamp has three dimmable presets and one preset for full-ON). I almost immediately knew what the problem was, so I took it with me. As expected, it just needed a new TRIAC. The original was a BT136-600D, and shorted between terminals T1, T2, and Gate. With only a 100-Ohm resistor separating the TRIAC’s Gate from the rest of the control board, I thought the COB would be dead. But a new TRIAC was less than $2, so I figured why not give it a try. Did that… and it worked!

One less item taking space in a landfill.

[momaka]

Originally Posted by eccerr0r

I also salvaged a Harrison Labs 6226A Linear PSU... (someone bone picked it as it suffered mechanical damage).

Same with mine in regards to mechanical damage - the frame on mine was all twisted and messed up. That's what caused the board to crack and break traces in several spots. I fixed both the board and the frame. Took a lot of beating to get that aluminum straightened. So I am not going to quit on it just yet.

Originally Posted by eccerr0r

I was wondering if I should just throw out the guts and replace them with an IC solution, higher chance of getting this solution to "fix" it than finding schematics and the germanium transistors.

Same here.
Was thinking just buy/build a cheap variable voltage supply based on a 317 regulator with a pass-through transistor. With the huge heatsink that the HP supply has, I could cool/dissipate quite a bit of power.

Originally Posted by eccerr0r

really no point in using an old CDRW drive anymore. I think at most I'd use this drive as a boot medium for test computers as my DVDRW drives are all in USB enclosures and tearing them out for an IDE-only machine is annoying.

IDK. I find the old CD-RW drives more reliable than newer CD/DVD-RW drives (though not always, of course).

I can't stand the slim, modern-day USB DVD drives - so fricken unreliable. Managed to burn a few coasters at work even with IMGBRN at medium recording speeds.

What I can't stand even more is desktop PC "towers" with those slim DVD drives (the same ones that are used in laptops and those USB DVD drives).

[Per Hansson]

Originally Posted by momaka

Just wait at the seashore for the glass bottle with message and parts inside it to arrive.

Awesome repair/WIP, Per!
When I see that kind of damage (main controller, CPU, etc.), I typically give up. That said, I do have a LinkSys WRT54G v2.0 with either dead controller, RAM, and/or ethernet switch chip (the one I mentioned in your thread above). Can't say for sure, as nothing seems to overheat excessively, but I do have a low resistance reading on the 3.3V and 1.8V lines. I probably won't use it... so if you want it for parts, let me know. It's different in design and layout from the routers you posted, though.

The first one where everything is fried I will not try to repair.
But the second one is worth it just for the fun
These have been abused like hell, living outside in tupperware boxes during snowstorms, it deserves my attention
I would not give up on your WRT54G so quickly, that's why I posted the update I did.
Connect a serial console to it (3.3v) and see if it says anything.
As you saw in this update one looked very dead but was very easy to fix:
http://www.badcaps.net/forum/showthr...451#post758451

[eccerr0r]

Originally Posted by momaka

Was thinking just buy/build a cheap variable voltage supply based on a 317 regulator with a pass-through transistor. With the huge heatsink that the HP supply has, I could cool/dissipate quite a bit of power.

I really want to make sure it operates about the same as before, trying to use a 317 I'd need to somehow make sure it can get down to 0V.

I can't stand the slim, modern-day USB DVD drives - so fricken unreliable. Managed to burn a few coasters at work even with IMGBRN at medium recording speeds.

What I can't stand even more is desktop PC "towers" with those slim DVD drives (the same ones that are used in laptops and those USB DVD drives).

Hmm, I haven't had much problems with the thin drives, but yes it's ridiculous that the newer "tower" PCs are using the slim drives - probably to reduce the number of SKUs ... grr. I have a feeling the 5.25 HH drives are no longer being built anymore?