820-3115-B Green light, no fan spin.

[gcain]

The board has a fluctuating PP3v3_SUS and PP5v_SUS.

The EN lines are unstable too. If I heat the PCH I get a fan spin, but am not sure if I am actually affecting something else....

Anyone with experience know if it's a PCH issue or if there is a component near by I am helping when heating the PCH?

Thanks.

 

[dukefawks]

It's power cycling. Was this liquid? Look carefully around clock chip area.

 

[gcain]

The board looks very (too) clean and I suspect there may have been liquid damage.

Do you mean to look around Y5010?
It looks very clean and tidy there.

 

[dukefawks]

No, did you even look at the diagram? U2600 is clock chip. Measure voltage peaks on Y2605 pins, need to know the highest value.

 

[gcain]

Clock "Chip" hmm, I was looking for a crystal.

Y2605::3 : 1.3v Highest. But usually around 200 - 300mV
Y2605::1 : is a round 8mV.

 

[dukefawks]

That seems ok. No signs of corrosion in U2600 area?
Is CPU Vcore pulsing too? Check R7402/3 for corrosion.
Any history on this machine? Usually they don't "just" stop working.

 

[gcain]

R7402/3 look ok.

Can't see any corrosion near u2600, but if I heat it up it boots every time. :/

Customer told me it just stopped working, but I can see liquid damage / sediment around the Q9707 area.

 

[ALB-Repairs]

PP3v42_RTC stable at every probe/Via?

To me it sounds like there could be a duff trace that reconnects when it heats up.

 

[dukefawks]

Boots as in it chimes and works?

 

[gcain]

I only have a screen plugged in; so boots as in backlight and grey screen.
It doesn't get much further, I think, because the board cools down too much.

 

[gcain]

I'll check when I get to the office.

 

[dukefawks]

Replace U2600 and the Xtal+the 2 caps.

 

[gcain]

Just to clarify, which two caps?

 

[dukefawks]

The ones on the Xtal lines.

 

[gcain]

lol C5010 and C5011?

 

[dukefawks]

Look at diagram at U2600 and don't tell me you can't figure it out.

 

[MDY]

Duke, when board is power cycling And 3V And 5V are pulsing, this is usually problem with chip clock?

 

[dukefawks]

Don't hijack thread. Cycling power can be caused by anything.