PS3 motherboard - COK-OO2

[Sadistic Taste]

Hi,

I'm was wondering if anyone on here could help me repair this PS3 motherboard, originally when I powered it on, it shut down right away, no lights.

I managed to figure out, that there was a short on the 12v line (IC6202 IP2003AP had shorted). I have replaced the IC, but the console is now showing the classic YLOD. I have reflowed the GPU and CPU, replaced the GPU, and still the same.

I'm wondering what might have caused the rectifier to blow in the first place, as this may lead me to find whats causing the YLOD. I only know basic electronics, so not really sure what to check next.

I couldn't upload the schematic, as it exceeded the upload limit.

Any help would be greatly appreciated.

[stj]

Re: PS3 motherboard - COK-OO2

maybe the proadalizer caps

[Sadistic Taste]

Re: PS3 motherboard - COK-OO2

Forgive my ignorance, but do you mean the NEC tokens? As one of them is slightly melted. I have removed a few from a scrap board, but have no idea how to test them, I only have DMM.

[stj]

Re: PS3 motherboard - COK-OO2

if they arent shorted then they are probably o.k.
read the capacitance if you have it on your meter.

[Sadistic Taste]

Re: PS3 motherboard - COK-OO2

Unfortunately, my meter can't read capacitance. I'll just have buy one.

[Sadistic Taste]

Re: PS3 motherboard - COK-OO2

I went ahead and replaced those caps, the ones I removed weren't shorted, replaced anyway, and still YLOD.

[stj]

Re: PS3 motherboard - COK-OO2

if the fan is running ful speed then it may be cpu overheating from bad paste under the metal cap(that you should have removed and re-done)

[Sadistic Taste]

Re: PS3 motherboard - COK-OO2

Fan seems to be normal, I re soldered the IP2003AP, just in case I didn't attached it right, and it went back to having a short on the 12v line, IP2003AP getting really hot.

I removed the IP2003AP, and replaced it with another one. There is a short again, but this time the resistance is 2 ohms, instead of 0.6 and it's drawing 3.3v.

[stj]

Re: PS3 motherboard - COK-OO2

interesting device.

if you have it removed, check the output pad for a ground-short.
and check the inductor etc.

[Sadistic Taste]

Re: PS3 motherboard - COK-OO2

Do you mean the pad on the motherboard? I checked that pad to ground earlier, and it was showing around 2 ohms I think.

It's still attached ATM, though it won't take long to remove it. I'll get back to you shortly!

[Sadistic Taste]

Re: PS3 motherboard - COK-OO2

I removed the chip, and measured from the output pad to ground, which reads 2 ohms. Also measured across the inductor, which is showing 0.2 ohms.

[stj]

Re: PS3 motherboard - COK-OO2

so you have a downstream short.
could be a ceramic cap - if your lucky.

[Sadistic Taste]

Re: PS3 motherboard - COK-OO2

OK, so how do I go about finding the cap that's bad?

[stj]

Re: PS3 motherboard - COK-OO2

good question - usually by lifting each suspect till the short changes!

[Sadistic Taste]

Re: PS3 motherboard - COK-OO2

OK, so I removed the RSX again and the rectifier. Still short, removed the 2 top NEC tokins, found one had a short, even though I already changed them, short gone.

Reballed RSX, soldered back the rectifier, check short, still gone. Replaced the NEC tokins, check short, still gone.

Attach RSX, short returns..

Removed 2 top NEC tokins, still short. Removed the 2 bottom NEC tokins, short gone. The tokins are ok, no shorts etc. So I checked the pads with my meter, and I noticed from the center ground pad to the outer pad closest to the RSX, shows 2 ohms.

So.. Bad RSX?

[TechGeek]

Re: PS3 motherboard - COK-OO2

It sounds like the RSX is bad and is causing something else downstream to short.