[SOLVED]820-2936 trackpad clicks but cursor will not move

[nate8organic]

got in a 820-2936 heavy liquid damage, have not cleaned it yet. was missing c7291 and c7251 guessing some one knocked them off the board. powered on and everythings working except the on board speaker will not play sound(tried a know good speakers already) and the trackpad cursor will not move (also tried 2 known good trackpads) the click button works but it does not sense movement.

Thanks for the help.
Nate

 

[dukefawks]

Check 3v3 S3 and S4 to connector. Check 18V5 to connector. For the 18V5 to work trackpad needs to be connected.

 

[nate8organic]

on r5800 i have 3.3v on pin 1 but pin 2 is 0v and on the connector its 0v. (how does s3 give power to to the trackpad if there is no part connecting 3v3_s3 to _s3_tpad?) also on probe 3 for 18v5 with tpad connected i have 0v.

 

[dukefawks]

Well, what does it say in the schematic at R5800?

3V present on pin 18 of J5800?

So 18V5 missing is the issue here. Z2_BOOST_EN getting to U5805? Trackpad needs to be connected!

 

[nate8organic]

at r5800 it says no stuff, i know there is no part there but even looking at the board i dont see how the power hops the pads. i didn't see any thing connecting the circuit in the board. it no big deal but i am getting ov at pin 18 of the j5800 with and without the tpad connected. i do have 3.3v tho on pin one of r5800 so the power is coming to there but idk how its connected to pin 2 or to pin 18 of the j5800.

i have 3.34v at pin 5 of the u5805, however i'm only getting 1.2v and on pin 4 p18v5s5_FB, and pin 8 p18v5s5_sw = 5v with trackpad connected.

 

[dukefawks]

Well U5805 is dead or something around it.

 

[nate8organic]

r5806 was missing. this board had a ton of parts knocked off it. its working now. as always thank you for the help duke! (solved)