820-3462 no power

[Kyle93]

Has no liquid damage. Only previous work looks like a bios change before it arrived here. Will worry about that after board fixed.

No green light.


PP3V42_G3H .42v

PPBUS_G3H 0.400v

SMC_RESET_L 3.42V

Checked around u7000 and noticed pin 27 only 0.48V.

Changed Q7080 a few times but no change. R7022 and R7021 have good values

What to check next?

 

[2informaticos]

"PP3V42_G3H .42v
-------------------------------
SMC_RESET_L 3.42V"
Impossible!!!
Please post accurate information...

Post Q6910 voltages and exact ohm resistance of R6912 (measured onboard).
Check if D6910 is not bad (open/short).

 

[Kyle93]

Yes PP3V42_g3h is 3.42V typo on last post.

Q6910 PPDCIN_G3H_ISOL 18.60V PPDCIN_G3H 18.60V DCIN_ISOL_GATE_R 6.78v

R6912 66.7 ohm

D6910 no short

 

[2informaticos]

Post U7000 basic voltages.

 

[Kyle93]

One of U7000 output voltages wasn't correct, Replaced U7000 and have light now and PPBUS_G3H is 12.28V.

Have a 0.03 short on pin 2 of R5281 so SMC is shorted.

Any ideas where a donar board can be purchased without costing $50-$60.00 US per board like on aliexpress?

 

[2informaticos]

Try to contact with Paul Lee, live:liblin88 on Skype.
Is the same gallaxyelectronics2015 eBay seller.
You can look on his eBay store, but has many boards unlisted for sure.
He makes good price for bulk, outside of eBay.

 

[Kyle93]

Have you talked to paul lately? I have been trying to get ahold of him on skype since the 5th with still no response.

 

[2informaticos]

I didn't contact him since long time.
Actual problems on China make things hard there...