Need Information, Bios Chip 25B64csig Acer TM P249

[ch3nzu]

Hai everyone, I need some help here.
I got Acer TM P249 notebook. Its not turning on when I press the power button. Already check the voltage pin, there is 3.2 volt. Its responding when I shorted it, the charging led blink 1 time, but noting happen.
There is 3V and 5V AWL.

I try to update bios (25B64CSIG), but when i check (adaptor is plug in), there is no voltage on each 8 pin (only 9mV high).
But when remove the bios chip from mainboard, there is voltage there.
Pin1 0.34V
Pin 2 0
Pin 3 3.4V
Pin 5 0.57V
Pin 6 1.506 V
Pin 7 3.4V
Pin 8 3.4V

What is the cause of it?
Is my bios chip is bad? (But I could read that bios chip with Rt809f programmer)

Sory for my language, its not my native language, hope u all can understand.

[mon2]

Re: Need Information, Bios Chip 25B64csig Acer TM P249

1) How are you updating the bios ? Did you remove this bios chip and use an external programmer & PCB to reflash this memory chip ?

2) Has the bios IC been removed before from the logic board ?

If the BIOS chip has been removed off the logic board, be sure to check the location of pin # 1 on the plastic housing of this chip. There is a proper orientation to the device. Perhaps the bios chip was not soldered back in the same direction and is now causing this fault ?

[ch3nzu]

Re: Need Information, Bios Chip 25B64csig Acer TM P249

1. Yes I removed the bios chip and used an external programmer Rt809F.
2. That ic been been removed before.

Already check the orientation of pin#1, I've soldered it in the right position (the same place with dot mark in mainboard)

I have check RSMRST at EC, there is no voltage.
Is that mean, i may have a problem with the chip itself or just need try to program it again with other bios rom?

I put the schematic below.
Bios chip (u29)
I jus wonder, the bios chip is gigadevice 25b64csig (used), but at the schematic it wrote w25q64fv.
Can i change the bios chip with winbond w25q64fwsiq? I want to know, because its really hard to find that gigadevice chip in my place. Are this the same?

[mon2]

Re: Need Information, Bios Chip 25B64csig Acer TM P249

Can i change the bios chip with winbond w25q64fwsiq?

No. The FW suffix part is unable to operate at 3v3. It is strictly for lower Vcc rail operation. Check the datasheet for details.

Can you post a clear picture of this chip soldered on your logic board?

The voltage levels are not making sense unless some other issue.

Ideally you should use the same Winbond memory device listed in the schematic. This is so the same memory commands continue to function such as Fast Read, etc. There is no guarantee that Gigadevice will offer the same opcode command support but you can compare the datasheets.

They should be available on AliExpress or similar.

[ch3nzu]

Re: Need Information, Bios Chip 25B64csig Acer TM P249

Can you post a clear picture of this chip soldered on your logic board?

Here the picture, i hope it clear enough
My mainboard model is DA0Z8VMB8E0 REV E. Dont know if that schematic is identical, but that as far i can get online.

If that posible that when we flash with wrong bios file, it could make the voltage to all bios pin is missing? Just curious.

[mcplslg123]

Re: Need Information, Bios Chip 25B64csig Acer TM P249

You can try Winbond 25Q64BV/FV