Diagnosing PSU


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If you're studying the PCB and are THAT close, why is the power on to even cause the pop? Haha, I always screw the supply back together before applying power, so you're obviously not safe either!

Most people approaching electronics for the first time are concious of possible electrical hazards but are unlikely to be aware of exploding caps so it was worth pointing out. I simply pointed out why it's a danger and the body part to protect. It's not a likely scenario by any means but again worth knowing about.

A friend that intoduced me to electronics long long ago actually reverse polarized an electolytic on purpose to show me the danger. Over the internet, my comment was the best I could do to return that Karma...

 

 

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Its not trolling to remind that the recommended option is to replace.  Best of luck in your endeavor on an EIGHT YEAR OLD PSU

The replace-rather-than-repair widespread mentality is all thanks to executives in the industry, as replacement means more profit. They couldn't care less about the environment, or cost to consumers. There's nothing wrong with attempting repair yourself, why do you think iFixit has become so popular? The age of the PSU is not even a factor. As long as he does the repair safely, and consults a qualified professional in person (as well as someone like me here) if he's not sure, or to have it safety checked following his repairs, he's fine.

He blew the chopper transistor anyway, he must have dropped a screw, so it probably doesn't matter. Always remember to use an old motherboard and old drives as dummy loads to test repair on a PSU as you monitor voltages using a multimeter (at the ATX connector, NOT inside the PSU while power is on!), DON'T use your daily driver equipment! And even more importantly, make sure to replace components with exact replacements, or dedicated equivalent replacements, sourcing them from decent manufacturers. Use Japanese capacitors instead of Chinese ones, and ALWAYS replace fuses (especially fusible resistors) with EXACT types, they are safety critical. Failure to do so will result in the PSU no longer meeting TUV Rheinland safety certification, making it dangerous and illegal.

I'm out of the thread now, I've made my point, and will communicate with Dill via PM, as we're both mature unlike some in this thread.

Edited by Tidosho
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usually it is cost prohibitive to repair vs replace...after all it is faster (time is money after all) to go and purchase a new one and be up and running quickly vs troubleshooting (this requires having the right equipment to be able to do so, which is also an added cost if you don't already have) and repairing (having the skills to unsolder and resolder components).  

Factor in the cost of a multimeter, possible oscilloscope, psu tester (so you don't have to use a mobo), solder gun, solder, components required to repair...it very well could add up to more than the cost of the one component that needs to be repaired/replaced....not to mention the time to learn how to use all of the equipment you just purchased.   For someone wanting to learn, sure it is a great project...for the average person or tech, not so much.

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usually it is cost prohibitive to repair vs replace...after all it is faster (time is money after all) to go and purchase a new one and be up and running quickly vs troubleshooting (this requires having the right equipment to be able to do so, which is also an added cost if you don't already have) and repairing (having the skills to unsolder and resolder components).  

Factor in the cost of a multimeter, possible oscilloscope, psu tester (so you don't have to use a mobo), solder gun, solder, components required to repair...it very well could add up to more than the cost of the one component that needs to be repaired/replaced....not to mention the time to learn how to use all of the equipment you just purchased.   For someone wanting to learn, sure it is a great project...for the average person or tech, not so much.

The problem is that I have already made the decision to repair this PSU before even starting this thread. I understand some people like to post threads without doing their research first, but I am not like that. 

Look at my post count, 99% of that was in hardware hangout, if thats not enough proof of my knowledge so far, then you will have to accept that I know what I am doing and am aware of the safety precautions when dealing with electronics. 

Furthermore, I have access to anything I need as I am working on my Computer Engineering undergrad at a University. I have also successfully soldered 0603 SMD resistors by hand before so I think I will manage soldering these caps on.

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I am not arguing that you can or can't do it.  Just simply stating why people would chose to replace vs repair is all. 

You want to repair, I am certainly not going to stop you and I am on your side if you do.  It is a great project to play with.

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There are too many parts that can be broken, if it's not visible directly which part is broken you have little chance in repairing it.
Sometimes it clearly visible which capacitor needs to be replaced but sometimes it's impossible to see and sometimes it's not just a capacitor... :( 

If you're still thinking about repairing it, try googling the PSU, in most cases the capacitors are to blame and people posted about it before with repair guides :)

Also keep in mind that testing is kind of hard with a PSU, you can't just use a multimeter safely to check voltages, those voltages can do serious harm to your body :rofl:

 

Went and googled your psu, the capacitors are known to be low quality xD

So here's a good video that's shows how you can find bad capacitors: https://www.youtube.com/watch?v=CLDJ1xc9Qc4 (2:16)

Edited by Seahorsepip
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Sometimes it clearly visible which capacitor needs to be replaced but sometimes it's impossible to see and sometimes it's not just a capacitor... :( 

If you're still thinking about repairing it, try googling the PSU, in most cases the capacitors are to blame and people posted about it before with repair guides :)

Also keep in mind that testing is kind of hard with a PSU, you can't just use a multimeter safely to check voltages, those voltages can do serious harm to your body :rofl:

 

We've already discussed all that and found it WAS capacitors causing it, but he then went and powered it up with a screw or something dropped inside and killed the main chopper transistor....

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We've already discussed all that and found it WAS capacitors causing it, but he then went and powered it up with a screw or something dropped inside and killed the main chopper transistor....

 

:rofl:  Atleast I was right about asuming that it probably was a capacitor :D

Had to replace a capacitor in a powerline adapter before, the capacitors inside those stop working in no time :p

Is there any chance that the PSU can be repaired now? I don't think that replacing transistors is gonna be easy and a simple fix...

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:rofl:  Atleast I was right about asuming that it probably was a capacitor :D

Had to replace a capacitor in a powerline adapter before, the capacitors inside those stop working in no time :p

Is there any chance that the PSU can be repaired now? I don't think that replacing transistors is gonna be easy and a simple fix...

If he dropped a metal object into the running P/S the damage becomes hard to predict since you can get a cascade effect where one failing item stresses another part of the circuit etc. Or just a single transister blew and it's still fixable. That power supply is new enough that there will also be some IC chips for the control logic, sometimes with integrated power transistors which can be much more difficult to determine as good or not.

But as a Zen thing, I could imagine an old man with a staff walking down rows of students with powered units and dropping screws in each one as a exercise in the art of repair. So the fun is still waiting...

 

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Thanks for the replies guys, and thanks for the link there seahorse.

I will be attempting the repair regardless if it fixes the PSU or not. I appreciate those who have put in helpful words.

p.s. SC302, Although my reply was to you, I was responding to more than 1 post that was made :)

 

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