Laptop arrived with coffee spilled around CPU power circuits and 5V rail short-circuited. Ultrasonic clean and some traces recovering were performed. 5V rail was fixed (faulty capacitor). Now the board has all power rails working. It spins fan when CPU temp. goes up, no image, CPU gets 0.75V for 3-4 minutes (no light on USB mouse) then it drops to 0.
The SPI flash W25Q128JVPQ was programmed with new dump (thanks to “hardware1”, who provided the file). No changes.
Pin 1 of the SPI IC (Chip Select CS) is always 3V, doesn't go low. As I understand it should be brought low for data exchange activation.
Pins 2 (DO) and 5 (DI) are also 3V, plain, without any traces of data transfer (as CS is high).
Pin 6 (CLK) 3V plain, no clock oscillation.
If I take the BIOS IC off the board, the pin1 (on board) has regular stable spikes 0-3V as well as pin 5(DI) gets regular signals. Pin 6 displays oscillation. Pin 2 is 0 (since IC is removed).
Is flash IC dead or….? I cannot rule out the flash IC fault as a working chip for replacement is unavailable at the moment. During reading/erasing/programming no issues arose (programmer is TL866A).
Any ideas what is the culprit and what to check, would be much appreciated.
No schematic diagram.
The SPI flash W25Q128JVPQ was programmed with new dump (thanks to “hardware1”, who provided the file). No changes.
Pin 1 of the SPI IC (Chip Select CS) is always 3V, doesn't go low. As I understand it should be brought low for data exchange activation.
Pins 2 (DO) and 5 (DI) are also 3V, plain, without any traces of data transfer (as CS is high).
Pin 6 (CLK) 3V plain, no clock oscillation.
If I take the BIOS IC off the board, the pin1 (on board) has regular stable spikes 0-3V as well as pin 5(DI) gets regular signals. Pin 6 displays oscillation. Pin 2 is 0 (since IC is removed).
Is flash IC dead or….? I cannot rule out the flash IC fault as a working chip for replacement is unavailable at the moment. During reading/erasing/programming no issues arose (programmer is TL866A).
Any ideas what is the culprit and what to check, would be much appreciated.
No schematic diagram.
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