Calling all computer experts - MEGA URGENT

[andy_con]

setup for a NYE laser show yesterday and everything was perfect.

went back today and my laptop has decided not to like mains power. it turns on and runs from the battery fine, but when i plug the mains lead in its not picking it up. so i can only run on battery.

been using the laptop all week and used it last night, so i dont know whats wrong.

ive checked the psu and its outputting the correct voltage.

in the below pic you can see the power connector where i plug the psu in. am i wrong in assuming that those pins on the back of the motherboard should be reading the same voltage as the psu is outputting?

not switching anything on, just plugging the psu in and measuring the voltage at those pins im only getting half voltage if not less. is this correct?

do i need a new motherboard? shall i cry as its NYE tomorrow and im screwed?

[mophead]

One would think those pins should be at the same voltage as the power supply. Check continuity between the pins and inside the socket itsself.

Might have to replace the socket or even hard-wire it.


EDIT: Both those pins appear to be connected to the ground plane (now i see the bigger picture) Ohm out the center post and the side lug and see what pins they connect to on the motherboard.

[andy_con]

One would think those pins should be at the same voltage as the power supply. Check continuity between the pins and inside the socket itsself.

Might have to replace the socket or even hard-wire it.

checked the socket and its making connection fine according to my power meter

[mophead]

Can you follow the traces from both the battery connection and the power connection to see where they intersect (at hopefully the charging circuit(chip)

[andy_con]

Can you follow the traces from both the battery connection and the power connection to see where they intersect (at hopefully the charging circuit(chip)

umm tired and goes to many places to follow

[mophead]

I had the exact problem with a laptop. What I ended up doing was resoldering the power conector. it had a cold solder joint that had worked loose over time.

[andy_con]

I had the exact problem with a laptop. What I ended up doing was resoldering the power conector. it had a cold solder joint that had worked loose over time.

have done the wobble test and all seem fine, but am warming up and soldering iron as we speak

[mophead]

snap a pic of the other side of the board while the iron heats up.....

[Carl B]

I would also say a dry joint between the mother board and the socket. try reheating the joints and add a bit extra solder to all the joints.

Carl

[Mr.Coffee]

does the laptop run off wall power when it's not connected to the system? a ground loop could be tripping some overload circuit. can you run the laptop with the power supply but not the battery?

Worst case scenario, do you have 1) another computer and 2)do you have an adapter (or external enclosure) for a laptop hard drive? if you had to, you could yank that drive and get the data off it so you could run on another computer. you could also look for a rectifier bridge that might be popped.