HP EliteBook 820 G4 - liquid damage - help

[maverick8]

Hi

I just got a HP EliteBook 820 G4 HSN-I01C 6050A2854201-MB-A01 i5-7200U with liquid damage. At the first check, the motherboard was short with no led light! After checking the motherboard I found a fired chip indicated in Area#1. After cleaning it, the short from the motherboard disappeared and the led light was presented, but not power on!

After second checking with 19,5V presented on the board I found a chip very hot indicated in Area#2 as needing to be replaced.

Can someone help me with a schematic for this HP? Or maybe some one help to find out what kind of chips I have to order for Area#1 (I have no info about it) and Area#2 (on this chip is noted as 1U=B1M but I can not find any info about it)

Please find attached all 3 pictures!

Thanks

[mon2]

Re: HP EliteBook 820 G4 - liquid damage - help

Ouch. With care and lots of flux - low air pressure but high enough heat, remove the balance of the burnt out part. Use gentle pushes of the tweezers to be sure the solder is in liquid mode before removing the dead body of the part. It is useless at this stage of the repair and you need to confirm the traces are still ok. Be patient and proceed.

[maverick8]

Re: HP EliteBook 820 G4 - liquid damage - help

Hi,

Thanks for all the info!

I can confirm all the traces now are good and can be used for the new chips.

I have difficulties in finding the chips indicated in the attached pictures ("1U=B1M" and "AREH 271"). Both chips are gone and I need to order them.

Can someone help me to find or identificate the chips?

Ouch. With care and lots of flux - low air pressure but high enough heat, remove the balance of the burnt out part. Use gentle pushes of the tweezers to be sure the solder is in liquid mode before removing the dead body of the part. It is useless at this stage of the repair and you need to confirm the traces are still ok. Be patient and proceed.

[mon2]

Re: HP EliteBook 820 G4 - liquid damage - help

See here:

https://www.badcaps.net/forum/showthread.php?t=90619

The 2nd IC is from Richtek.

RT9715HGB 1U= SOT-23-5

First ic is from MPS.

From the above webpage,

ARE* NB685AGQ QFN-16 (3mm x 3mm)

Each will be available on AliExpress.