3437 Very Slow

[wirelessplanet]

Got a 820-3437 that powers on and boots up. It has full fan spin and is very slow. All temp sensors show normal in mac fan control. I have replaced the trackpad and flex which didn't fix issue. no signs of corrosion or water damage. The only thing abnormal was a loose screw around c7323. s5 hs computing is reading normal in diode mode .141 so i don't think that caused any damage.

 

[2informaticos]

First, do PRAM reset.
Try another LIO board/flex.
Also try disconnecting webcam.
Run ASD EFI version and report any error.

 

[wirelessplanet]

https://imgur.com/a/opabYsL

looks like it has cpu sensor, air flow and camera sensor bad

 

[2informaticos]

"Also try disconnecting webcam."
Did that?

 

[wirelessplanet]

yes i did. I replaced the logic board with an all good board and everything is working fine. so i know all parts are good.

 

[2informaticos]

Seems to have a problem on SMC S0 "1" SMBus.
Check R5360/61 first.
Also check solders and traces around U5800.
Be sure to have good connections to its temp sensors.

 

[wirelessplanet]

trace seems to be fine in diode mode and resistors are reading 1.9k i reballed u5800 connections and resistors to be sure. getting same errors. should i replace u5800?

 

[2informaticos]

"Be sure to have good connections to its temp sensors."
I mean to Q5810/30/60...

 

[wirelessplanet]

so i found a short on c5811 and traced it back to u5800. replaced it and now its passing asd.

thanks for the help!