Corsair GS800 Power Supply Problem

[ShortCircuited]

Re: Corsair GS800 Power Supply Problem

very good find! keep my fingers crossed that it works after you reassembled it.

You read my mind....will install and see and of course let you know what happens.

[ShortCircuited]

Re: Corsair GS800 Power Supply Problem

Odd...Hooked to a 125watt desktop. Computer powers on instantly does not load windows and does not respond to the power button. PS acts as if it is in constant power on state. Voltages are all normal. Odd.

[ShortCircuited]

Re: Corsair GS800 Power Supply Problem

PG is only .0873v

[ShortCircuited]

Re: Corsair GS800 Power Supply Problem

Probed the IC (WT7502) that provides PG signal. Does the problem look like an IC issue or a problem elsewhere? These values are from power on state-the only state I can get from the power supply (constant on) and green to ground no connection:

[R_J]

Re: Corsair GS800 Power Supply Problem

The power supply should not come on when there is nothing connected to it, if it does then something is telling one of the optocouplers to turn on the main primary supply I don't know which one it is but I suspect it is the one (U3?) just below the J22 letters. The other opto next to it is likely for feedback for the main supply, and the other optocoupler by itself, is feedback for the standby circuit.
If the power supply is in standby there should be no +12v,+5v,+3.3v going to the WT7502
The PSONB seems high, I would think it should be around +5v or less (the datasheet says max 7v)

[CapLeaker]

Re: Corsair GS800 Power Supply Problem

I think a valid PGI is more than 1.5V. I guess you have to trace that pin back.

[R_J]

Re: Corsair GS800 Power Supply Problem

Check that the power supply is in standby when not connected to any pc. If the main power supply comes on before the ic sees a PS/ON signal the ic might not detect the voltage properly and give a false error

[Per Hansson]

Re: Corsair GS800 Power Supply Problem

Great fix so far!
But please attach photos to your posts.
I have attached the previous ones.
It is a great shame when a thread like this comes up empty without photos because the image-host has closed doors!

[ShortCircuited]

Re: Corsair GS800 Power Supply Problem

My motherboard went out on my main PC the same day I got to this point.* RMA mode on that. Yeah Photobucket ruined a lot of these repair threads. Thanks for fixing the photos.

WT8502: https://cdn.badcaps-static.com/pdfs/...b7fe85fcd7.pdf


Tracing PGI circuit back-not far-I think I found another issue here...:


15.6v seems high going into the the resistor and cap that are in parallel, which then drops drastically at the cap (c75) and resistor (R67)? Measures 8100ohms across the the cap and resistor. If normal my PGI signal would be 15.6v. Believe spec sheets indicates max voltage of 7v. Bad cap or resistor? Pin under PGI is gnd on Wt7502.


*Next day was a Booster Coil in a Samsung monitor.

[CapLeaker]

Re: Corsair GS800 Power Supply Problem

the smd resistor marking is 9101? So it should measure 9.1 kOhms. A bad cap would read a short or some low Ohms and that is not the case.

[ShortCircuited]

Re: Corsair GS800 Power Supply Problem

The resistance is 9093ohm appears as I would expect-yes 9101, so why a 15v drop across the two? Leads back to the transformer (secondary side of course) that we originally discovered had a broken solder joint. When trying to check capacitance the meter just can't lock..keeps going back to OL then like .8uf and kinda bouncing back and forth. If the cap, how to speculate the value-size and 15v+ minimum?

[CapLeaker]

Re: Corsair GS800 Power Supply Problem

Put your finger on that resistor. Is it getting hot?

[ShortCircuited]

Re: Corsair GS800 Power Supply Problem

Put your finger on that resistor. Is it getting hot?

Didn't feel warm...checked the resistor and the cap.

[R_J]

Re: Corsair GS800 Power Supply Problem

Where is the 16 volts coming from?

[ShortCircuited]

Re: Corsair GS800 Power Supply Problem

Where is the 16 volts coming from?

Main transformer that we fixed earlier in this thread...through a diode a resistor/cap (parallel).....long trace another resistor/cap (ones in image-parallel) then into the PGI pin.


One side of the transformer is 12.3 and the other is 15.6-both of which are on the secondary side of the main transformer.

Neg probe is the ground/blk wires on secondary side.

Red line (roughly):

[R_J]

Re: Corsair GS800 Power Supply Problem

So what voltage do you have on pin #1 ? While you are checking, what are the voltages on all 7 pins? I believe pgi voltage is quite low but needs to be above 1.2v.

[ShortCircuited]

Re: Corsair GS800 Power Supply Problem

So what voltage do you have on pin #1 ?

Pin 1 of Wt7502 is PGI and it is 1.6



What is more problematic is that if the cap just before pin 1 is bad then Pin 1 would receive 15.6 volts if corrected and the max voltage is 7 according to the spec sheet for PGI for WT7502.

Correction to post 51: 14v drop not 15v drop.

[R_J]

Re: Corsair GS800 Power Supply Problem

pgi of 1.6v should be ok, it is above 1.2v (I did'nt see the <.> in the post# 49 picture)

[ShortCircuited]

Re: Corsair GS800 Power Supply Problem

.08v good for PGO?

Connected to PC and it would not boot to windows...black screen despite voltages 3.3v, 5 and 12 all present.

[R_J]

Re: Corsair GS800 Power Supply Problem

NO, The ic does'nt just rely on the pgI input pin to give a pgO, high