Laptop Sony Troubleshooting

[kozman]

Hi Members,
I have a Sony Vaio laptop model PCG-5K1L. Laptop had water spilled on the keyboard. I installed a used tested motherboard. Nothing moves or lights up. I am using a new power supply for that model laptop and have checked the output voltage to be good.
I am testing the board with it out and the power board and switch board attached. Also the CPU, fan and heat sink, and memory.
Next I purchased a power board and then the switch board (all used). Nothing. I do not get any lights nor does the CPU fan move.
I have tried with the memory in and out. I have tested with the battery in and out with power adapter.
I cannot think of anything else I did. Well I did not replace the CPU. Would a bad CPU not enable the CPU or power LED to light? Even for an quick blink?
With out a schematic can I test any components or follow power on the board?
Do I need something else connected to the mother board to get it to turn on. All that is left is the keyboard, screen, modem.....
Peace,
kozman

[14049752]

With a liquid spill, any answers that you get will just be guesses. It sounds like you're using known good parts to eliminate the problem....that's all you can really do aside from very carefully inspecting each component for signs of damage

With that....go ahead guys...make your guesses.

[Martyn]

I tipped a can of beer in my Sony a few years ago and it was as dead as a dodo for about 18 hours and suddenly just started up again.:D

[meanderer]

have you checked the power button and it's related signal path?
for example. when the switch is depressed, is it showing a short circuit (completed path)?
if it does, then trace the button from where it is back to the power board contacts, do the same. Then trace it back to the flex cable, do the same until you hit the motherboard.

Water damage can be very strange. If it doesn't boot there's really little worth to revive it. I would bet the data is perfectly fine however.

[kozman]

I have checked the power button using a meter. Just continuity with the power off. I works on and off. I will try to trace the power out of the switch.... the power button board and the power board plug into different spots on the mother board. Tracing through connectors with many contacts will be dificult not to mention just following a trace. Not sure if the board has multi-layers. But I will try and see how far I get tomorrow.

[kozman]

Well good news.System is working. I have to tell the truth. There was a daughter board I did not connect to the mother board. It has a SD card reader on it. I did not think I needed it to test the mother board.
It did not work with the card in until I unplugged the bios battery and then reattached it. ??? This was on the re-certified mother board I bought. For smits and giggles I tried the same routine on the original mother board. It worked also.
So the mother board without the daughter board did not show any sign of of life (no lights even). The mother board with the daughter board attached did not show any life. The mother board with the daughter board and cycling the the bios battery power worked. Both boards showed the same results.
I never seen anything like this without even seeing a led at least blink once.
Peace,
kozman