DOM MB V5 Diagnosis page

Board ID:

V5 00417

Source:

George Chao

Symptoms:                            

ADC Channel 3 reads unusually high. (5V power)

Analyst(s):

G. Przybylski

Analysis Procedure(s):

Confirmed high power consumption on 5V by measuring voltage drop across R68.
With non-contact thermal probe, look for hot spot on board. Isolate U31.  Probe output voltages when outputs set to extremes.
Channel 0 output incorrect when set to %x0. Expect 0, read 0.9V.
Lift U31 pin 20, and run STF... All serial ADC tests OK.

Root cause:

Suspect U31

Mitigation:

Request U31 replacement.

Disposition:

If this board passes STF after U31 replacement, then mainstream.

Any Other Information:

Traveler