A 1708 820-00840

[ipetro]

NO IMAGE !
20V/0.780A
DEAD CPU ?

 

[2informaticos]

Change title accordingly!
I'm not sure what schematic to look at...

 

[ipetro]

A 1708 820-00840​

 

[2informaticos]

Any history available?
Do you get CPU core voltage?

 

[ipetro]

in the U8400 area there was some oxidation, apparently water got in at some point!
PPVCCGT_S0G_PH1,2,3=0,693v
PPVCCSA_S0G=0.837v
PPVCCCPU_S0G=0.001v
PPVCCGT_S0G=0.667v
PP1V2_S3=1.2v
PPVCCIO_S0G=0.597v
PP1V_S3=0.995v
PP1V_S0G=0.995v

 

[2informaticos]

Looks like bad CPU.
You get iGPU core voltage, instead of CPU core...

 

[ipetro]

are you kidding me

 

[2informaticos]

iGPU core voltage shouldn't be there.

 

[ipetro]

what generates CPU voltage?

 

[2informaticos]

PCH, CPU and BIOS are involved in CPU core generation; as for iGPU too.
You should get aprox 0.6V at CPU core (after 5-10s) and NO voltage at iGPU core.

 

[ipetro]

ACT_THERM_TRIP_L=1.5v
SMC_PROCHOT_L=0.002v
Are these indicators normal?

 

[2informaticos]

I don't think to be relevant in this case.

Just in case, try known good BIOS.

 

[ipetro]

after replacing the BIOS I got power
PPVCCCPU_S0G_PH1=0.955v
PPVCCCPU_S0G_PH2=0944v
but still no image

 

[2informaticos]

Do you still have iGPU core voltage?
Should NOT...

 

[ipetro]

yes

 

[2informaticos]

Then bad CPU...