820-4924 Keyboard only not working.

[wgaca]

Liquid damaged board, repaired, and cleaned. The keyboard is not responding at all other than the power button.

Tested with new known good trackpad and trackpad flex, still the same issue.
I tried replacing U4820 and U4830, still the same issue.

There are not broken traces on the trackpad and keyboard connectors.

Any ideas?

 

[2informaticos]

Can you do SMC reset, PRAM reset?
Check voltage and diode mode at I2C_IOXP_SCL/SDA lines.
U4820/30/50 get power?

 

[wgaca]

I tried SMC reset and it worked. however, after the SMC reset it doesn't turn on at all.
As far as i remember PRAM wasn't working when i tried it before that.

I2C_IOXP_SCL/SDA diode - 651/622
Can't check voltage as it doesn't turn on now, i'm back on fixing it. PPBUS is 12.49, doesn't look like an SMC fault

 

[2informaticos]

Board cannot stop turning on because of SMC reset.
Once both charger and battery are removed, SMC reset is done automatically when power is applied again.
I asked about reset, to see if special keys and U4850 work at least.
Check diode mode at SCL/SDA lines w/ and w/o trackpad connected.

Be aware, recently had same problem and solved it only after trying 3 new chinese trackpad cables.

 

[baker_jeff]

Silly question, did you try a new keyboard?? How about external USB keyboard? Does that function?