Hi,
I'm new in the world of repair, and I have a laptop that does not turn on.
I don't know exactly the past of this laptop, I got it in a non-functional state.
The LDO3 and LDO5 are present, and it provides 3.3 and 5V.
When I started to diagnose the motherboard, the regulator for the LDO3V and LDO5V was quite hot, I checked it with a thermal camera, and the 3V from the DNBSWON was missing, so I replaced the IC Chip from a donor board (the ic chip is from the same type of motherboard)
Now, the regulator is fine, it's not heating, and I also have a 3V voltage on the DNBSWON (power on button), but if I short it, nothing happens. The resistor's value before the IC chip drops to zero, and according to the tracking the #DNBSWON should be high after the IC chip registers the turn-on signal, but that does not happen.
The main voltage is present on the motherboard, but I have no idea what should be the problem.
The NVVDD is a little suspicious for me, but I read somewhere that this value can be good for this type of laptop, and if I tried to inject voltage (0.8V) the current draw is low and nothing is heating.
Here are some basic resistance measurements:
5V (5V_S5) 1,55 kOhm
3V (3V_S5) 6,7 Ohm
NVVDD(SW 1-6) 0,2Ohm
NVVDD(SW 7-8) 28Ohm
VCC_CORE 6,5 Ohm
VCC_SOC 14,8Ohm
1,8V_S5 7,8kOhm
1.1V_SUS 4,7kOhm
Can you please help me? I have no idea what should be the problem.
I'm new in the world of repair, and I have a laptop that does not turn on.
I don't know exactly the past of this laptop, I got it in a non-functional state.
The LDO3 and LDO5 are present, and it provides 3.3 and 5V.
When I started to diagnose the motherboard, the regulator for the LDO3V and LDO5V was quite hot, I checked it with a thermal camera, and the 3V from the DNBSWON was missing, so I replaced the IC Chip from a donor board (the ic chip is from the same type of motherboard)
Now, the regulator is fine, it's not heating, and I also have a 3V voltage on the DNBSWON (power on button), but if I short it, nothing happens. The resistor's value before the IC chip drops to zero, and according to the tracking the #DNBSWON should be high after the IC chip registers the turn-on signal, but that does not happen.
The main voltage is present on the motherboard, but I have no idea what should be the problem.
The NVVDD is a little suspicious for me, but I read somewhere that this value can be good for this type of laptop, and if I tried to inject voltage (0.8V) the current draw is low and nothing is heating.
Here are some basic resistance measurements:
5V (5V_S5) 1,55 kOhm
3V (3V_S5) 6,7 Ohm
NVVDD(SW 1-6) 0,2Ohm
NVVDD(SW 7-8) 28Ohm
VCC_CORE 6,5 Ohm
VCC_SOC 14,8Ohm
1,8V_S5 7,8kOhm
1.1V_SUS 4,7kOhm
Can you please help me? I have no idea what should be the problem.
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