820-4924 Slow/Unresponsive

[Ryanlen2]

Was liquid damage around ISL, KB connector and SMC.

All that as been replaced.

It will now turn on and boot, but is very slow to display LCD and will only eventually display LCD and boot with an SSD or via USB is installed.
Without a drive attached it will turn on, fans spin but screen will stay black.

Also missing audio & KB once in OS.

If I hold down option key nothing is displayed just black no BL.

If I PRAM I get nothing as well.

Also tried different bios just in case. Same result.

Thanks. Have a good one.

 

[dukefawks]

Trackpad needs to be connected for KB to work. Bad trackpad cable is the #1 failure on these machines so start there.

 

[Ryanlen2]

Sorry. I forgot to mention that I have replaced the cable with 821-00184. Trackpad works. External KB works.
More concerned with booting issues.
also will not chime due to no audio.

Internal KB shows in Sys Report. Only power button working. This with new KB and connector.

Thanks Duke!

 

[dukefawks]

Keyboard has only 2 data lines to the trackpad so either something up with those or no power to U4820/30. I2C_IOXP_SCL and SDA. Keyboard should be an easy fix and maybe it is causing the slow boot issues.

"Without a drive attached it will turn on, fans spin but screen will stay black." Fan should not spin on a 4924 that is not hot. Crap under SMC suspected.