820-00165 no fan spin

[Gmorb]

All resistors and traces on spi termination to pch and u6100 are fine.

 

[2informaticos]

Did you try BIOS file from the forum?
Clean ME dump is already posted for this kind of board for sure...

 

[Gmorb]

Reprogrammed the bios with a clean me and still nothing.

 

[Gmorb]

Just got a rigol Ds1102e have no idea how to use it or what to look for but maybe you can give me some type of guidance on what to look for to hopefully get this going?

 

[2informaticos]

YouTube should have many videos about using o-scopes.
Apart of names, there is not too much difference between cheap digital o-scopes.
Usually, auto mode should be good enough.

https://www.eevblog.com/ has good reviews and explanations about million of electronic tools...
I think they have some tricks to extend frequency range too (by software).

 

[Gmorb]

figured out the oscope a bit and going back to the question

"PM_SLP_S5/4_L no reaction at R5115/16?
Use an o-scope to catch any rapid pulse there..."

i do get rapid pulse on PM_SLP_S5/S4_L
Not sure if that helps any tho..

 

[2informaticos]

OK, check now for pulse at L7520.
If PM_SLP_S3_L pulses too, yo should get pulses at all the other coils; less the CPU ones maybe...

 

[Gmorb]

i get pulses on l7520 and PM_SLP_S3_L and checked other coils before i got pulses on all of them except the backlight coil

 

[2informaticos]

Post voltages for U6100 pins.
O-scope should show some activity at pins 2, 5, 6.

 

[Gmorb]

pin 2,5 and 6 do show activity o-scope says 36v seems odd but multimeter shows 3.3v on those pins rest of the pins are 3.3v according to multimeter except pin 4 of course

 

[2informaticos]

When PCH access SPI chip, pins 5 & 6 go low.
Even pin2 should drop to 1-2V I think.

Seems that you do not read correctly your o-scope.
Be aware of gain probe. It should have gain control on the probe and software too.

 

[Gmorb]

ok well i had the max voltage too high o-scope showing 3.60v on those pins now. when i trigger smc_onoff_l i get a pulse but voltage stays the same. i do see a slight fluctuation of 3.60v to 3.80v on u6100.

does this mean the pch is not reading the bios then?

 

[2informaticos]

Do you get 24MHz at R1915?