820-3476-a turn on no display

Dewanbd

Member
Unit had water damaged close to R5498 and C5549.
R5494 : 17.75v. Fan spinning normal, CPU is not getting worm.
Missing EDP_PANEL_PWR_OR_PSR_EN on pin 1 R8319
Have PP3V3_S0 on pin 8 of U8330 .
PP5VS4 is present.
PPVCC_S0_CPU: 1.69V
Known good display connected.
Dont know what to next, any help please.
 

2informaticos

Administrator
Staff member
Pins 28-30 of J8300 must get 5V, at least in the first few seconds.
This voltage is not maintained if pins 1 & 4 of U8330 don't go high.
Checl these pins and be sure L8300 is OK.
 

Dewanbd

Member
Pins 28-30 of J8300= 0v (in the first few seconds, when board starts ,Disconnect J8300)

1 & 4 of U8330= 0v ,(in the first few seconds, when board starts ,Disconnect J8300)
Checked twice.
 

Dewanbd

Member
After changing Bios , CPU getting hot and found USB activity on I/o card side but no USB activity on other side no display as well.
 

Dewanbd

Member
After smc reset i see the Diplay and chime too. Could you please tell me how to do clean ME bios. Thanks for your assistance.
 

Dewanbd

Member
Hi, from where i should buy Medusa 2? I am using CH341A but this one sometimes cant recognize some bios chip. any suggestion please.??
 
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