TWPno3 (EM_H8316_N14H_V1.0) Netbook power on, no image/backlight, shorted?

[Agent24]

Just had a go at trying to fix a "TWPno3" netbook/laptop. It seems to be based on something that's been rebranded many times.

Very similar to: https://www.veropc.gr/product_detail...9-94-VRNV142R4

The mainboard is labelled EM_H8316_N14H_V1.0


It can charge the battery and it can power on, but only the power LED coming on - no screen backlight or image or anything.


I checked voltages on the board and found that the BIOS was getting 0v in power off state and when powered on, only 0.35v.

The BIOS is Winbond W25Q64FW and runs between 1.65-1.95v, so clearly 0.35v is far too low...

I checked from W25Q64FW VCC pin 8 to GND and found a dead short there.

I tried injecting voltage (1.3v) to the rail and found it would take up to 3A (limit of my bench PSU) and voltage on BIOS chip was again 0.3v. This was with everything unplugged from the board (including battery).

Tried alcohol, nothing obvious, then tried freeze spray and the only thing apparently heating up was a spot on the edge of the CPU die. No ceramic capacitors heated up as I hoped they would.

Is the CPU shorted? It looks like it to me... is anything else likely?

[anshad]

Re: TWPno3 (EM_H8316_N14H_V1.0) Netbook power on, no image/backlight, shorted?

The description you written suggests a shorted SOC [ System on Chip - CPU and traditional Chipset in a single silicon die ]. This kind of SOC chips are prone to failure easily.

[Agent24]

Re: TWPno3 (EM_H8316_N14H_V1.0) Netbook power on, no image/backlight, shorted?

The description you written suggests a shorted SOC [ System on Chip - CPU and traditional Chipset in a single silicon die ]. This kind of SOC chips are prone to failure easily.

Yes, it's an Intel Atom (or maybe Celeron?) SoC. That's a shame. It would have been nice to play with and stick Linux on it perhaps, if it'd worked. Oh well. Out it goes for spare parts I guess. Thanks.