Asus Memo Pad ME301T backlight issue

[tibimakai]

I know it's not a TV, but it's about LCD/LED and backlight issue.
I have picked up from the bay, this broken tablet, that could not be turned on.
I have manged to turn it on after I have charged it and updated it, which did not help.
The problem is that plugged in the backlight is not going full power and it keeps blinking.
When the charging cable is unplugged, the backlight never turns on, nothing can be seen on the screen.
All software stuff is turned off, brightness is at maximum.
To me, it seems like not all LEDs are lit up.
The charging LED blinks on and off, with the backlight. Some king of shortage? Since last night when it was charged to 100%, next morning it was showing 74% and it wasn't used at all.
Tried to wiggle all the ribbon cables, took the tablet apart, put it all together, no change.
It could be something in the LCD? Bad contact on the PCB or LEDs, maybe the ribbon is loose behind the tape of the LCD? I can't get to it, until the digitizer is not removed. This would be the last resort.
Any help is appreciated.

[tibimakai]

Re: Asus Memo Pad ME301T backlight issue

Nobody has any ideas?

[david37g]

Re: Asus Memo Pad ME301T backlight issue

I tried to repair the back light circuit on an RCA tablet. The flex cable that goes to the lcd also goes to the back light. There were two visible soldered joints on one side of the cable for the back light circuit. The mother board has a dc voltage doubler circuit that boosts the battery dc voltage of 3.5 volts to 7 volts for the back light. I used a 7.5 volt wall wart and pins to tap into the flex cable and the back light lit up. Would not light with 3.5 volts.
So far I have not been able to identify what back light component is bad. There are several mosfets, capacitors and diodes. I have no schematic to trace the circuit