DOM MB Diagnosis page

Board ID:

V5.0L 000725

Source:

George

Symptoms:                            

Failure during HASS.  No longer boots up.

Analyst(s):

G. Przybylski

Analysis Procedure(s):

Measured   1.8V  delivers about 1.1V.  Suspect switcher U8.
Suspect faulty U8 or U8 soldering.  See pix; doesn't look too bad.
12/1/04 Helen Chen replaced U8.  Subsequently,
No boot failures during over 500 reboot cycles while sweeping the temperature between -55°C and +65°C every 90 minutes
Low temperature profile from -40°C to -75°C results:
At and below -65°C, Local coincidence loopback failures
At and below -70°C, ATWD B Ch 1 8PE Ped fail, and ATWD B Ch 1 8PE fail

Root cause:

Possibly U8, the power switcher chip

Mitigation:

Replace suspect U8

Disposition:

Mainstream, if it passes STF tests..

Any Other Information:

Traveler Preliminary
 Traveler  September 27
Pix of U8 pads