820-3536 not turning. MLB clicking noise L7130 area

[BCN_Techs]

Hi,

Got this logic board. Green-> Orange lights PPBUS present but every 5-6 seconds logic board is making a clicking noise in L7130 area and PPBUS is going down to 3-4V than again 17V.

PP3V42_G3H - OK
PPVRTC_G3H - OK
PP5V_S5 - OK
PP3V3_S5 -OK

ALL_SYS_PWRGD is 3.3 right when the board is clicking, after 0V. Almost all reails have variations while it is clicking. SOme of that more than other.


It was water damaged ISL 629 area that had been cleaned and repaired all traces and components.


Thanks.

 

[2informaticos]

"PPBUS is going down to 3-4V than again 17V"
17V on PPBUS_G3H, are you sure???

Remove F7140 and get correct voltage at L7130 first.
If you really have 17V at L7130, then change Q7130, maybe U7100 too.
Be sure, R/C7125 are both good...

 

[BCN_Techs]

Solved. Was trace between R7152/7151 and R7150

Thanks

 

[JohnB8812]

I would replace the ISL as well as it probably got killed...

 

[BCN_Techs]

You are right it was killed, but didnt replaced because already fixed that area. Seems only traces were missed.

 

[JohnB8812]

Yes but I'm saying to avoid a warranty return I'd replace it as well. Chip could've gotten a little messed up not be totally dead.

 

[BCN_Techs]

ah ok. will do that thanks