Samsung tab 4 7.0 won’t turn on after screen replacement

@jayeff thanks for your reseponse. I unplugged the battery first as always, then the digitizer.

I normally don’t take the logic board out on my Samsung tab repairs bc I see it as an unnecessary step. Do you think this may have been an issue?

Thanks

Hi @wizard870 ,

Hopefully the heat used on the digitizer panel did not get through to the logic board and affect it somehow.

Can you prove somehow that the replacement screen is OK or have you another one to try?

I didn’t think about the heat. The replacement is okay. Do you think it could be the battery flex, seeing how it’s booting on then off? (Without any logo)

Hi @wizard870 ,

It mightn't be the battery flex as something may be causing it to shutdown before it gets to showing anything.

Suggest that you disconnect the battery flex and then disconnect all the flex cables that you previously disconnected and clean their contacts with IPA 90%+ (Isopropyl Alcohol). Also clean the systemboard flex cable connectors (that you removed the flex cables from) with IPA 90%+ then ensure that they are all reconnected securely.

Just surmising that you may have inadvertently touched the bare connectors on a flex cable with your fingers and this may have made for a poor connection when the cable was re-inserted. After cleaning them with IPA (use a QTip moistened with IPA to wipe the bare cable contacts and systemboard contacts clean. Wait for it to dry also ensure that there are no fibres coming off the QTip) Then if possible either use gloves or do not handle the bare ends when reinserting the cable into the connector.

Can you get into recovery mode at all?

No I am not able to get into recovery mode. Actually, I have to hold power button down for awhile for backlight to even show up. There are two spots on the LCD as well when back light does come on.

I will try alcohol treatment when I am back in the office.