Technical Support Missing PP1v2_S3 on 820-000165

[Patrick Ribbsaeter]

Missing PP1v2_S3 on 820-000165... any suggestions Master?

 

[Hosein Asadolahi]

Missing PP1v2_S3 on 820-000165... any suggestions Master?

check u7400 and its circle such as vldoin , v5in , s3 , s5 ...
if that ok check page 19 of schematic .

 

[Patrick Ribbsaeter]

Background info:
The motherboard was water damaged and had corrosion around U7400 which I cleaned up.

Troubleshoot done:

1. Missing PP1v2_S3 ON VLDOIN...
2. U7400 Pin 12(PP5V_S5) = 5.1v
3. U7400 Pin 16(VDDQ/VTTREF ENABLE) = 3.3v
4. U7400 Pin 17(VTT ENABLE) = 3V
5. SMPS = STUCK at 0.111 AMP - Indication it could be PM_SLP_S4 ?

Question:

1. is it U7400 that creates that power rail/voltage?
2. What to check on Page 19... Its only pull-up resistors there for PP1V2_S3.. but that voltage is missing, so what why check that page?

 

[Patrick Ribbsaeter]

UPDATE:

1. I changed the U7400, found a bad trace under the IC.
2. With SMPS I get 0.360 Amp and then drops to 0.036amp after 10 seconds and stays there.
3. With a normal DC charger 85w I get 0.360 Amp and very high FAN spin.
4. No image