820-3115 1/4 fan spin

[mooserov]

Going through the rails, everything above pp5v_s5_LDO is stable, PP5v_s5_LDO jumps a bit when the fan pulses, from 4.89vto 5v. Every voltage below that pulses. Everything appears to be trying to come on. Is there a standard way of attacking 1/4 fan spin?

 

[dukefawks]

If the fan pulses then all rails will be pulsing too. Was this liquid? Is CPU Vcore pulsing too?

 

[mooserov]

Yes liquid, CPU Vcore is pulsing too.

 

[dukefawks]

If there was liquid in the U2600 area this would be a very good 1st suspect.

 

[mooserov]

area had a little water damage, went ahead and cleaned up from a donor just in case. Still has the 1/4 fan spin.

 

[dukefawks]

U2600 was replaced now? R7402/03 ok?

 

[mooserov]

yes, replaces. R7402/03 are ok.

 

[mooserov]

u6100 pin 8 looks like garbage, this has to be reprogrammed, correct?

 

[dukefawks]

Yes, see if you can read the original first. ME region should be rescued if possible, you cannot just use a BIOS from another board.

 

[mooserov]

any recommendations on a reader?

 

[dukefawks]

TL866 is the usual choice.

 

[mooserov]

thanks Duke, on a slow boat from china to me now.