Anyone good with schematics ?

[Big Jim]

Customer brought in a Toshiba P850 which wasn't powering on, quick test reveals faulty DC Jack, I do a quick solder job to confirm it and it powers on fine, customer doesn't want to pay for repair so I take the laptop in exchange for the diagnostic fee.

Some plastic is broken, so i order that and a new dc jack, dc jack is on a harness but is soldered to the board.

DC Jack arrives, I replace it myself, probably one of the easiest dc jack replacements I have done, everything went very smoothly.
however, laptop no longer works.

I am getting 19.5 at the DC Jack, all caps on the board appear to be ok when tested with Ohm meter.

This is pretty much where I get stuck however as I can only poke a DC tester at the board with no real understanding of what voltages I should be seeing.


So the power switch is on a ribbon cable, which has 4 connections, 2 are reading 18.5v and 2 are reading 19.5 v. I have tested the button itself with ohm meter and 2 of the contacts make a 0Ohm circuit when the button is pressed.


I have a copy of the schematic (attached) but I don't understand what I am looking at (it may ask to install an additional language/font pack, it did for me)



Any of you guys could steer me in the right direction ?

 

[Larry Sabo]

Have a look at the videos on this Electronic Repair YouTube channel for guidance. See at the bottom where it has some of the most popular videos showing how to diagnose a dead laptop.