820-00928 | A1707 | One fan full blast

[rvanpruissen]

This one came in with only 0V on one of the USB ports in one orientation. Changed the corresponding CD3215, first problem solved, it now has 20V and boots.

Next problem, it now has a left fan that's on 100% all the time. Temps look ok (no reason for high fan temp wise).

Ideas?

 

[brunomotter]

Run HWMONITOR to see what sensor is reporting high temperature/current

 

[rvanpruissen]

All of those look fine to me, but I'll have another look. Any reason to use HWMONITOR over https://github.com/exelban/stats ?

 

[2informaticos]

Check starting in diagnostic mode if any error pops up.
Tried known good fan?

 

[rvanpruissen]

Diagnostics result: PPF003, there may be an issue with the fan. Don't have a known good fan for a 1707, but tried one from a 1706/8, that caused the same behaviour but also the other fan to spin up, so no conclusive answer there.

Sensor values:

 

[2informaticos]

Compare voltage and diode mode readings between Q6000/50 areas.

 

[rvanpruissen]

One of the PWM lines measured above 1v to ground. Replaced corresponding transistor and it was around the correct 0.85v again. Fixed. Thanks!