PC P&C Silencer 420W

[4m0k]

Re: PC P&C Silencer 420W

Any progress on this one? I have Corsair VX450 with almost the same symptoms (no burnt coil in mine). Shorted: q302 (18n50), d304 (stth8s06d), d303 (1n5406).
I am going to replace all of the above and also two liitle caps: c308 (22uf 50v) and c104 (47uf 25v), though I'm still looking for the spares.

[Colt45ws]

Re: PC P&C Silencer 420W

I took a picture of the the whole bottom board and of the coil. The coil actually looks more burnt towards the top of the glue, rather than where the glue was black which is the clean spot.

[Trinite]

Re: PC P&C Silencer 420W

Are you sure those aren't the rectifiers? They look like FETs because they contain two diodes and thus require three input leads.

[Colt45ws]

Re: PC P&C Silencer 420W

I was not sure on the FET part right after I posted and saw BDxxx by each of them on the board. They are going to coils; so that would explain that?

[Toasty]

Re: PC P&C Silencer 420W

They read shorted or they're wired together? Sure they're FETs? Again, surrounding circuitry. They're usually pumping coils.

[Colt45ws]

Re: PC P&C Silencer 420W

Hmm, on the output side, all the FETs have the two outside pins shorted. Normal?

[Toasty]

Re: PC P&C Silencer 420W

Not necessarily. Coils and caps will screw with a diode check or ohmmeter. When you get those kind of reading, you have to get it out of the circuit to be sure. Unsoldering one leg is a quick way, but SMD's don't lend themselves to that easily. Leaded ones do.

[Colt45ws]

Re: PC P&C Silencer 420W

Reads 22Ω either way. Diode check shows .015v (?) I checked some of the other SMD diodes on the board for comparison and most are around .5v with one other at .02v. It would seem to me the ones that are low are shorted, right?
The transistors are not shorted.
The coil has so much of the glue and Im not sure how to remove it without damaging the coating.

[Toasty]

Re: PC P&C Silencer 420W

From what I can see that resistor's marked 220. That's 22Ω and you'll read that no matter which way you probe. Diode check setting, correct? If it read lower one way, then I'd say the diode was shorted.

Are the transistors reading okay?

If you don't find anything, then I would order the repair parts and the new caps. Get it back together and do the series lamp to see what happens.

Attached all the photos here as I discussed in the other thread and also so I don't have to keep jumping back to Page 1.

Toast

PS: What happened with the coil? Did you get it inspected?

[Colt45ws]

Re: PC P&C Silencer 420W

Im getting 22ohm across them either way with the probes. But they are in parallel with a resistor, so I should 'see' the resistor one way and virtually no resistance the other, right?

[Toasty]

Re: PC P&C Silencer 420W

Yes. Look to be D305/306.

[Colt45ws]

Re: PC P&C Silencer 420W

Thats what I thought, and is why I have three of them. That was 3-4 years ago, though. Now I look here and on JG so I have mixed brands now.


Those glass diodes are the little red things?

[Trinite]

Re: PC P&C Silencer 420W

I thought PCP&C was supposed to be the holy grail of PSUs? This thing looks very plain. Like a run-of-the-mill Delta with crapcaps.

Depends on what unit you get. PC P&C has some absolutely superb units as well as some that are fairly mediocre. I have a 610W Silencer that is rock solid. But some of their cheaper units (at least the older ones) I'd avoid. It really depends on who they contract their units out to.

[370forlife]

Re: PC P&C Silencer 420W

Run of the mill seasonic with subpar OST's. About sums it up for PC P&C. They do, or well did, have better units with better caps, but at the price point no. Too many other companies selling the same performing, or even just the same units with 120mm fans and modular cabling for cheaper prices.

Their new units are okish performing High Powers.

[weirdlookinguy]

Re: PC P&C Silencer 420W

I thought PCP&C was supposed to be the holy grail of PSUs? This thing looks very plain. Like a run-of-the-mill Delta with crapcaps.

[Toasty]

Re: PC P&C Silencer 420W

Keep looking at all the caps then, even output side. Something did that.

[Colt45ws]

Re: PC P&C Silencer 420W

No, physically all the components look to be 100%.

[Toasty]

Re: PC P&C Silencer 420W

About $7.50 + shipping from Digikey.

I would check the SMD components nearby. Q303/304 and the 4 diodes (2 glass, 2 flat pack D301/302) as they are providing the drive signal to both FETs gates. A leaky transistor or diode could be altering the drive waveform causing one or both FETs to stay on too long. One is off when the other is on and vice versa. If they both or one is on when the other comes on, it will overload (eventually) and pop.

Are the FETs physically damaged? Cracked or cratered? If not, you still need to find the noisemaker...

If everything checks good, then follow the SMD transistors drive back to the middle of the board and that daughterboard. There's another 2 SMD transistors there. The daughterboard probably has the PWM/PFC chip(s) on it.

Toast

[Colt45ws]

Re: PC P&C Silencer 420W

The FETs are 18N50, D304 is STTH8S06D, and D303 is 1N5406
Any idea as to what caused the initial failure?

[Toasty]

Re: PC P&C Silencer 420W

Best to replace both FETs. What are the numbers of the bad parts?