Hi to all, this laptop came with no signs of life, no battery chargin and no start.
I found that the main 19v rail was almost shorted, it measured around 7 Ohms , then searching better I found a shorted MP86945A DrMOS (between Drain and Source) that converts the 19 volts into the PCH core voltage...
I was going to chuck the towel, but I had a new same DrMOS then decided to solder it in, then I connected the power jack and the system now powers almost on, all the voltages rise but the CPU core and VGFX core.
Externally I only see that keyboard backlight lights up for 2 seconds, FN and Capslock leds light and stay up forever, and that power led (near power jack) starts blinking continuously after 4 seconds.
I know that 19v may have hit the PCH core then it should be definetly damaged, but I can't explain why RAM voltage (and others like 0.9v) rises but CPU core doesn't.
I don't have any Intel 10th gen power sequence, so I don't know if RAM voltage should rise before or after CPU core voltage.
Theoretically, PCH should output SLP_S5 and SLP_S4 signals if it works and all previous conditions are met, and then after RAM voltage should rise, so in theory PCH maybe still work...maybe only on some degree...
I've inserted a Clean ME bios image but nothing changed.
I've already searched for info and problems about similar Huawei laptops that uses the same Monolithic Power circuitry with the MP2979A IC, and it seems that many users had similar problems with this IC (Fn+Capslock leds on indefinetely), that has an integrated eeprom that may corrupt and it's difficult to restore without the proper development tools.
Please, anyone could share a schematic or a power sequence from another HP latop that uses a similar 10th gen Intel CPU?
Or maybe suggest other things to try?
Thanks
I found that the main 19v rail was almost shorted, it measured around 7 Ohms , then searching better I found a shorted MP86945A DrMOS (between Drain and Source) that converts the 19 volts into the PCH core voltage...
I was going to chuck the towel, but I had a new same DrMOS then decided to solder it in, then I connected the power jack and the system now powers almost on, all the voltages rise but the CPU core and VGFX core.
Externally I only see that keyboard backlight lights up for 2 seconds, FN and Capslock leds light and stay up forever, and that power led (near power jack) starts blinking continuously after 4 seconds.
I know that 19v may have hit the PCH core then it should be definetly damaged, but I can't explain why RAM voltage (and others like 0.9v) rises but CPU core doesn't.
I don't have any Intel 10th gen power sequence, so I don't know if RAM voltage should rise before or after CPU core voltage.
Theoretically, PCH should output SLP_S5 and SLP_S4 signals if it works and all previous conditions are met, and then after RAM voltage should rise, so in theory PCH maybe still work...maybe only on some degree...
I've inserted a Clean ME bios image but nothing changed.
I've already searched for info and problems about similar Huawei laptops that uses the same Monolithic Power circuitry with the MP2979A IC, and it seems that many users had similar problems with this IC (Fn+Capslock leds on indefinetely), that has an integrated eeprom that may corrupt and it's difficult to restore without the proper development tools.
Please, anyone could share a schematic or a power sequence from another HP latop that uses a similar 10th gen Intel CPU?
Or maybe suggest other things to try?
Thanks