Corsair GS800 Power Supply Problem

[R_J]

Re: Corsair GS800 Power Supply Problem

They must control that baord, because the pfc and the main supply need to be turned off in standby.

After looking at the CM6800 datasheet, I wonder if they controll the VCC line to the CM6800?
Did you take any pictures of the riser board with the ic? It would be nice to know which pins of the ic connect to which pins on the riser board.

[ShortCircuited]

Re: Corsair GS800 Power Supply Problem

OK I desoldered that 5th pin (runs to U3/PC1 top-right pin) on the riser card on primary side and it did power off. I feel like that is progress. So that riser card/CM6800 is sending power on signal in err. It did not boost primary side (160ish volts) and secondary side did not power on.....I did not check stand-by voltage though. Id dint want to leave it on and mess it up.


Now with that off can I safely test the secondary power on signal to U3 pin 1?

I will look through photos and see.

[R_J]

Re: Corsair GS800 Power Supply Problem

Ok, so that 5th pin could be the vcc supply? On Q2 it seems the base connects to the U3 opto, does Q2's emitter pin connect to hot ground?

[ShortCircuited]

Re: Corsair GS800 Power Supply Problem

Ok, so that 5th pin could be the vcc supply? On Q2 it seems the base connects to the U3 opto, does Q2's emitter pin connect to hot ground?

It looks like Pin 13 on the CM6800, which is Vcc that runs to pin 5 on the riser card and off to U3(top-right) primary side of course. Only thing on the riser board between IC 6800 and pin 5 is a 0 ohm SMD.

Q2.... you mean Q12....about an inch above U3 (on/off OC) primary side? Q2 is just above the fan header I annotated before. I will look into specs on Q12 and see what is going on with it.

[R_J]

Re: Corsair GS800 Power Supply Problem

It must be Q12, again its hard to make out the numbers sometimes, So it's collector connects to pin5 (pin 3 is not connected, correct? so I am counting from the same direction)
So does Q12 emitter connect to the VCC supply? if it does, check that it is not shorted, if it is shorted it would never turn off the vcc to the cm6800.
Got a number on Q12?

[ShortCircuited]

Re: Corsair GS800 Power Supply Problem

It must be Q12, again its hard to make out the numbers sometimes, So it's collector connects to pin5 (pin 3 is not connected, correct? so I am counting from the same direction)
So does Q12 emitter connect to the VCC supply? if it does, check that it is not shorted, if it is shorted it would never turn off the vcc to the cm6800.
Got a number on Q12?

Yes, pin 3 on riser board is NC and the 5th pin is the one next to (left) the one that is circled on the silkscreen. Top-Pin to Q12 (emitter?) (ZDW 19) connects to Vcc on cm6800.

Top/middle pin of Q12 and the bottom-right pin is 2 ohm. Short? The bottom-left pin does not seem to be connected to the other two pins on Q12 in the off state-simple continuity check. I do not have a valid spec sheet on Q12/ZDW 19 so I cannot speak specifics on it.

[R_J]

Re: Corsair GS800 Power Supply Problem

The ZD is a PBSs5350t, here is the pinout. I suspect the transistor is shorted emitter to collector, that would explain why the ps won't turn off.
W = made in China
19 = date code

[ShortCircuited]

Re: Corsair GS800 Power Supply Problem

The ZD is a PBSs5350t, here is the pinout. I suspect the transistor is shorted emitter to collector, that would explain why the ps won't turn off.
W = made in China
19 = date code

Will these or these work as replacements?

I knew I remembered the "ZDW": https://www.badcaps.net/forum/showthread.php?t=83465

[R_J]

Re: Corsair GS800 Power Supply Problem

Will these or these work as replacements?

I knew I remembered the ZDW: https://www.badcaps.net/forum/showthread.php?t=83465

They won't work, "these" are N channel mosfets, you need a PNP transistor

[ShortCircuited]

Re: Corsair GS800 Power Supply Problem

Do you need to order them or do you have "these" if you need to order them, order the originals

I have "these" and "these" Dang...cant wait a month from china....Will dig through my bin and see...maybe I will find something on a scrap PCB. Will update the thread as soon as I find something.

old roomba board is loaded with W2T W2Xs and A7Ws....?

Will re solder pin 5 to riser card and remove that transistor and see if it stays off. Safe test?

[R_J]

Re: Corsair GS800 Power Supply Problem

I have "these" and "these".

"these" won't work. you need "this"...PBSS5350t PNP transistor

[ShortCircuited]

Re: Corsair GS800 Power Supply Problem

"these" won't work. you need "this"...PBSs5350t PNP transistor

Thanks...will source this'es.

Would these work? I can get these within a reasonable time frame and if that fixed this PS I could acquire an original for a final solution. Can't seem to find the 5350ts in USA.

Specs:Collector-Base Voltage: 40V
Collector-Emitter Voltage: 40V
Emitter-Base Voltage: 5V
Collector Current: 200mA
Mfr: ON Semiconductor
Package: SOT-23
DC Current gain: 30-300

[R_J]

Re: Corsair GS800 Power Supply Problem

Thanks...will source this'es.

Would these work? I can get these within a reasonable time frame and if that fixed this PS I could acquire an original for a final solution. Can't seem to find the 5350ts in USA.

Specs:Collector-Base Voltage: 40V
Collector-Emitter Voltage: 40V
Emitter-Base Voltage: 5V
Collector Current: 200mA
Mfr: ON Semiconductor
Package: SOT-23
DC Current gain: 30-300

Not going to work, only 200ma, you need 2amp
Digikey has the originals

[ShortCircuited]

Re: Corsair GS800 Power Supply Problem

Found another ZD SOT 23

Testing the replacement out-of-circuit:
1. collector-emitter: no drop both directions (diode test)
2. collector-base: .6v and 0 drop (diode test)
3 base-emitter: .6v to 0 drop

Seemingly functional? If so, I will install. The original is definitely shorted from collector to emitter.

[ShortCircuited]

Re: Corsair GS800 Power Supply Problem

Catching up (almost a year)...Power supply was constant power-on state. We found Q12 (primary side PNP transistor shorted collector to emitter out-of-circuit and possible (actual) cause for constant on state. Replaced w/ PBSs5350t as R_J stated to me repeatedly-THANK YOU! No longer constant on when replaced. PSU now only gives +5vsb. Main cap is 160vdc.

[ShortCircuited]

Re: Corsair GS800 Power Supply Problem

When I plug in this power supply tester I have 15ohm on +5v rail. If I simply jump green-ground at 24-pin for power on signal this short is not present. Verified PS tester works on another known good PS.

Pulled the only +5v signal from this daughter board to the main PCB which runs from this daughter board and the 15 ohm short remains. Will dig around on the daughter board.

[ShortCircuited]

Re: Corsair GS800 Power Supply Problem

Applied 12v to daughter board and it drew 300mah (PS set to 800mah). U1/uP3861P did get warm. Any ideas on testing this 20-pin to confirm? Thanks for any help. PS tester makes a very interesting high frequency noise/squeal not made when connected to other power supplies.

Anyone know where would I find these uP3861P? OrderNo. uP3861PSAF SOP-20L

[R_J]

Re: Corsair GS800 Power Supply Problem

Without the ic driving UG & LG the vcc current should be around 5~10ma @12v. Check that the mosfets are not shorted. As for a source, likely China

[ShortCircuited]

Re: Corsair GS800 Power Supply Problem

In-circuit PH1 (8) is grounded (15 ohm) to daughter board ground.

Pin PH1 (8) to PGND (10) is 15 ohm in-circuit

Pin PH1 (8) to GND (4) 15 ohm in-circuit.

I'm no EE...just an unhealthy obsession with fixing "stuff." This appear problematic? Maybe LG1 or UG1 shorted as you suggested?

Pic shows PHL circuit. Sure seems the short is in this region.

Looks like alibaba is only source. Emailed mouser and digikey for availability.

Q 6, 7 and 8 are identical. Probing Q7 and Q8 in-circuit from D to S is 15 ohm. surrounding CCs are not showing short in-circuit.

Pulled D2 short remains. Diode good.

[ShortCircuited]

Re: Corsair GS800 Power Supply Problem

Pulled Q6, Q7 and Q8 15 ohm short remains. D/S diodes checked out OK out-of-circuit.
Pulled U1 short remains. UGH

red dot to green dot is 128ohm in image below. This is the same for the 3.3v, and 12v rail to ground, but 15ohm to the +5v rail and open circuit when power supply tester is removed.

red dot to yellow dot is 15ohm in image below.