820 3437, Green - orange light , not turning on!

Noguinfor

New member
Hey ,

Working on 820 3437, initial the board start, fans spins only after 30-50 sec but don't have any chime! first impression the board is very clean but with a real inspection i noticed U7501 have a bit off humidity! pins 23-24 because off the corrosion don't do the contact component-Board! i take the U7501 reconstruct the trace and ressolder the component U7501. After this the board don't start anymore !! already replace U7501 for new on and same history, no fan!!

i already double inspect and don't found more humidity !!!

ppbus, PP3V42_G3H , PPVRTC_G3H, PP5V_S5, PP5V_S4RS3 - ALL OK

MC_ADAPTER_EN, PM_BATLOW_L, SMC_PM_G2_EN, SMC_RESET_L. - ALL OK

only don't have PP5V_S0 !!

any idea???
 

2informaticos

Administrator
Staff member
U7501 controls only PP5V_S4RS3, not PP5V_S0.
PP5V_S0 is generated by U8080, controlled by PM_SLP_S3, via U8180.

Do you miss more voltages?
 

2informaticos

Administrator
Staff member
Other coils pulsing?
Is always better to use o-scope, to check pulses...
Normal DC multimeter will not catch the peak value.
 

2informaticos

Administrator
Staff member
"all pin's are pulsing"
Do you mean pin8 pulsing too?
There is PP3V42_G3H, should be stable...

Check now all the SPI termination resistors.
Also check traces around U6100, try new BIOS...

Inspect carefully the area where you worked first time, around U7501.
Maybe some resistor/trace affected close to it.
 

Noguinfor

New member
You hit full, Bios problem! i replace a bios for another donor board and the machine comes to life!! but, now i need a BIOS! i will update a original bios here!
 

Noguinfor

New member
unfortunately it did not work. fans only stop 1 time, and spining always! i will program another bios with TL666! i'm using a ezp2010 it may be that!
 

2informaticos

Administrator
Staff member
BIOS chip from donor board gives ME issues...
I'll try later to build another for you.
Post the latest dump you tried; the one stuck in logo...
 
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