# Oops broken power supply



## Savjac (Apr 17, 2008)

I know one of these items is broken, but they all look good, I am thinking a hammer is in order now.
There used to be a time I think when broken stuff was really apparent, so I need to break it worse then I will feel ok with the new power supply and its costs.


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## orion (Sep 18, 2009)

I usually look at the back side with magnifying lens to look for cold solder joints. Other than that its hard to troubleshoot a board without any sort of schematics ( for me anyways) Google is your friend though if you enter the model or part number you may find others with similiar issues that may have had some resolution.


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## Savjac (Apr 17, 2008)

Thanks Orion, 

I looked with the glass and found nothing really so I did call the manufacturer and they told me what it was. We had a power outage, or should I say almost instant out then pop back on and when that happened it apparently broke the power supply. A new one was ordered and installed and today it works like new.


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## RBTO (Jan 27, 2010)

A lot of equipment servicing has moved from component level troubleshooting to board level, at considerable cost to the owner if that equipment needs repair. Chances are, the problem is a solid state device, like the power transistors in the bottom-left heat sink, which can be replaced for a few dollars at most. Have you priced the cost for board replacement?

A good example was a voltage regulator board in a 5KW generator that I own. It went bad and in checking with the company which manufactured the generator, a new board was in excess of $150. I took the time to reverse engineer the board, and determined it was a single $0.25 component (a thermistor) and got the generator up and running again. I feel bad that so much equipment goes to the scrap heap when really simple things cause their demise. It's the society we live in. The upside is that we have these marvelous toys which couldn't exist without the complex circuits, but even then, it's a shame that resources aren't available to do component level repair.

If you have any electronic skills at all, it might pay you to check some basic components (transistors and diodes), especially if the replacement board is expensive. If not, get the replacement, and go at the old board to see if you can repair it and keep it for a spare.


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## lcaillo (May 2, 2006)

You can check the diodes and transistors with the diode check on most multimeters. The chips are hard to check for much but shorts. What is it from and what does it do, not do?


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## Savjac (Apr 17, 2008)

It is a power supply for my speakers, well one speaker. 

I colored out the manufacturer on the board, I don't want anyone to think it was their mistake, it seems to be the power surge and yes it was plugged into a protector, evidently not a good one though. 

I really did not know how to do checks or anything beyond a couple of touches between my multi meter and solder joints and with no idea what values should be, I gave up. Ordered a new power supply and kept the old one to play with. The unit was about $110 delivered to my house and imo was worth it. 
Some of those parts are molecular in size it seems. 




lcaillo said:


> You can check the diodes and transistors with the diode check on most multimeters. The chips are hard to check for much but shorts. What is it from and what does it do, not do?


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## Tonto (Jun 30, 2007)

Most people here don't advise a surge protector/conditoner with battery back up. I bought as APC S15 from Vann's when they offered that special 3 years ago ($375 or there abouts, shipped). I live on a canopy road & we have lots of surges & outages. The city just upgraded our grid to underground utilities due to the frequency of problems. Even with that, my unit is frequently having to add current to the load. I think it was a good buy, at least I rest easier every time I hear it kick on & that little blue light comes on. I have a battery back up UPS on my PC as well.


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## RBTO (Jan 27, 2010)

I can appreciate your reluctance to troubleshoot your old PS. Most of the diodes can be tested in-circuit, but you'd probably end up needing to remove the transistors to check them, and if it's a factory marked integrated circuit, forget it - even professionals would be lost without a schematic.

Relating to what Tonto mentioned, a UPS is a good idea, particularly if you're in an area with frequent power interruptions, but keep in mind that some UPSs don't include transient protection, and you want to size the UPS appropriately according to your load or you can end up with problems. Keep in mind too, that if the power goes down, the UPS will only support your load for a given time, and you should plan on disconnecting the load prior to that time. For devices which include hard drives (computers, satellite DVRs, etc.) a UPS (and transient protection) is highly recommended.


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## lcaillo (May 2, 2006)

Tonto said:


> Most people here don't advise a surge protector/conditoner with battery back up. I bought as APC S15 from Vann's when they offered that special 3 years ago ($375 or there abouts, shipped). I live on a canopy road & we have lots of surges & outages. The city just upgraded our grid to underground utilities due to the frequency of problems. Even with that, my unit is frequently having to add current to the load. I think it was a good buy, at least I rest easier every time I hear it kick on & that little blue light comes on. I have a battery back up UPS on my PC as well.


There is no reason not to use a surge suppressor with a battery backup. No need if it has adequate surge protection built in.


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