820-3023 3 beeps no PPVCORE_S0_AXG_R

[rzeszu]

Hi
I have this board for repair.
I checked power rails and:
only PPVCORE_S0_AXG_R this is 0V
ALL_SYS_PWRGD present
Still dead, fan spinning, and made 3 beep only.
I stuck with that.

Kindly Regards Mariusz

 

[dukefawks]

AXG not present is normal.
1.5V present at L7330? If yes then this is going to suck. Inspect for liquid near RAM and CPU.

 

[rzeszu]

Ok, 1.5V present
I see some components are cleaned after liquid.
I forgot about one thing.
I replace u7400 and its starts but stop working after 5 minutes.
I thought that if CPUIMVP_AXG_PGOOD from U7400 is 0, and i change u7400
You wrote that AXG is not present is normal, please tell me when i should get it?

 

[dukefawks]

AXG is not important. Is the machine working now but shutting down after 5 minutes?

 

[rzeszu]

Now is dead.
Only beeps.

 

[rzeszu]

I have good working board for test for now. I put it to test other parts in this computer and now have same problem - 3 beeps WTF?
Is it possible that fault caused by display?

 

[dukefawks]

I very much doubt it. Disconnect it and see if it chimes.

 

[rzeszu]

No, now I have 2 boards with same problem
I connect only IO board and speaker.

 

[dukefawks]

Bad RAM, corrosion under RAM/CPU or cracked traces.

 

[rzeszu]

Ok i could understand it with first board which has some corrosion but what with KGB which is use for tests and now have same problem?

 

[dukefawks]

I don't know what you did.... 3 Beeps is something with the RAM. ESD damage, slipped screw driver, corrosion, bad luck. I just know that 3 beep boards when L7330 has 1.5V are a nightmare.

 

[rzeszu]

Ok i will reball all chips just for fun or sport or ...
And close this repair
Thanks for help.
Regards Mariusz