Why Capacitor Selection and Cooling Matter

[[Spectre]]

This particular power supply just came out service due to bad caps as can be seen by the two leaking and the three bulging caps which have all failed on the DC side. The unit tests dead on all rails. These are/were Fuhjyyu capacitors from a lightly used PC that had been in service for about 2 years. So when we comment on capacitor selection or cooling solutions in reviews we aren't just picking at nits these are issues that can and will crop up in time periods longer than we are able to have units for review purposes.

 

[Ihaveworms]

What brand was that?

 

[Bbq]

Going by a couple features (fan grille shape, cable sleaving, heat shrinking, design, etc) I would say it's an older Antec Smartpower.

How close am I?

 

[[Spectre]]

Going by a couple features (fan grille shape, cable sleaving, heat shrinking, design, etc) I would say it's an older Antec Smartpower.

How close am I?

Close but it was a Truepower.

 

[veedubfreak]

Looks like all the old Dell motherboards i had to deal with a few years. I loved that whole capacitor fiasco. We had roughly a 75% failure rate for a year on the machines we ordered. Luckily Dell was kind enough to pay us 50 bucks per machine to repair them under warranty

 

[Dangman]

Did that PSU take out the system as well? Or did it keep its death to itself?

Damn. Now I really do need get my bro to replace his PSU. He has a Smartpower...

 

[BillParrish]

I bet that supply has a fair amount of ripple.

You mainly cannot do a lot about the overloading other than buy a bigger supply, and the ripple x ESR causing internal heating/boiling of the electrolyte again is a design issue you cannot correct (but another reason to look for supplies with low ripple. )

One thing I have done that has almost eliminated power supply failure in my machines in the field is to go with cases that have 120mm exhaust fans in the rear. Getting the heat out the back ASAP and NOT using the power supply as a major exhaust route for the internal case heat is a major plus. Another failure of the ATX case design that has outlived its usefullness as far as high performance is concerned but no good alternatives exist (yea I know about BTX, I said good alternatives )

I wonder if they make solid caps of the size and capacatance needed. Hmm buy [insert name here] with a new all solid cap design for longer service life !!

 

[[Spectre]]

I bet that supply has a fair amount of ripple.

Not anymore it doesn't

I wonder if they make solid caps of the size and capacatance needed. Hmm buy [insert name here] with a new all solid cap design for longer service life !!

Some are available there are still some sizes like for the primaries that are not. In any case they add quite a lot to the cost of the unit.

 

[larrymoencurly]

Close but it was a Truepower.

Is it because SmartPowers don't have that big square yellow polyfuse on the separate small circuit board? What's that thing for?

 

[[Spectre]]

Is it because SmartPowers don't have that big square yellow polyfuse on the separate small circuit board? What's that thing for?

That, the PCB, and there are some componenets that are different. I'll have to open it again to see what exactly that polyfuse is for on the PCB and let you know. When I saw it is more of gee thats neat...followed quickly by damn the caps blew on another one time to toss this unit so I didn't pay very close attention.

 

[Farva]

Ya, after discussing this with OK_Wolf on a Antec 550W TPII, he told me to crack open the PSU to see if there were any bulging caps. Sure enough, two caps were leaking and 4-5 others were bulging. I'm glad I found that out before it took out my 2.2TB server.

 

[Rabid Badger]

I found something interesting yesterday; capacitors that are actually worse than Fuhjyyu. I opened up a failed Deer 250W I found buried in my new office out of pure morbid curiosity and found this:

Sorry about the camera phone pic, but you get the idea. On the lower right of center we see two perfectly intact Fuhjyyu caps, while on the upper left of center there are two ruptured caps. The brand on these was Yihcon. Leave it to Deer....

 

[MichiganTeddyBear]

)

I wonder if they make solid caps of the size and capacatance needed. Hmm buy [insert name here] with a new all solid cap design for longer service life !!

While many solid caps of the proper rating do exist, as mentioned previously, they can get pricey.

Now for the drawback.. even solid caps will dry out and exhibit ESR out of tolerance. I have repaired many a monitor (sony, high end digitally controlled CRT's) that had solid caps that had dried out.. now get this, they were in a cool part of the monitor, the circuit board that houses the digital guts of it. nice and cool there, not near any hot components, and with plenty of air circulation. Still they dried out.

Solid caps are not the solution to all the cap problems, but a step in the right direction. As long as we have caps, we will have caps drying out and failing.