Asus Transformer T100HA short on MB

[suiramix]

Hi there,
Got this (dead) Asus Transformer T100HA, like new condition, no history...open up and disconnected the battery and press the power button for 10 sec. reattached the battery (measured it at 3.4V) ...no joy! Without the battery connected, plugged the USB charger ...no power up , dead ! Noticed a hot spot on the motherboard (second MOSFET labelled "A" is burning). So far, using diode mode on multimeter, checked for short capacitor and found C1 and C2 "shorted"...removed them but same issue . The capacitor are OK ...also inductor L show is shorted ...so the defect is still there...running out of ideas ... anybody has the schematics ? Thanks...

[mon2]

Re: Asus Transformer T100HA short on MB

Have the limited attachments for you to study. These are diode readings.

[suiramix]

Re: Asus Transformer T100HA short on MB

Thanks Mon2 ! I will try to measure those voltages...

[mon2]

Re: Asus Transformer T100HA short on MB

Just found the boardview file for this logic board.

Part that is heating up is identified as a CHARGER IC from QUALCOMM. See attached.

The boardview viewer will show the same details.

The following Aliexpress store appears to have this part but as always, do your homework:

https://www.aliexpress.com/item/4000...archweb201603_

Do note that this is the BGA package - NOT QFN. Here are some other vendors that claim to offer this component:

https://www.digipart.com/part/SMB1357

PS: Try MobileSentrix.ca - have used them a number of times for repair parts and they do carry some weird stuff. Otherwise, source from Asia.

[suiramix]

Re: Asus Transformer T100HA short on MB

Thanks again for your help mon2 !...I did identify that Qualcomm SMB1357 charger IC. I have taken a photo with an IR camera and beside this charger chip (not that hot) the diode (PD8102) and MOSFET PQ9201 are really burning...see attached.