ANOTHER 820-4924 trackpad issue

[MegaObi]

Hey guys.

this one is fully working system but the trackpad fails - i tried a good working trackpad & keyboard it worked. After few restarts and sitting around for a bit NO trackpad again! It doesnt seem to have any corrosion oh water damage.

im not sure what the best way to diagnose these issues.

I have taken some voltages from around trackpad connector.

pp5v_s4_tpad_f 5.19v
pp3v3_s4 3.33v
smc_lid 3.3v
smc_pme_s4_wake_l 3.297v
tpad_spi_if_en_conn 3.33v

Where is good place to start looking?

 

[2informaticos]

Check if trackpad/keyboard always work on boot menu.
I suppose you have an issue once logged into OSX.

Inspect trackpad connector.
Keyboard still working, only trackpad issue?

 

[MegaObi]

yes i check once logged into osx. Actually no keyboard AND no trackpad
i cant get into boot menu when i hold option? maybe coz keyboard also not working

 

[JohnB8812]

I assume you tried known good trackpad flex not just Tpad itself?

 

[MegaObi]

yep i got a good working shell so i just transplant the logicboard to eliminate keyboard/trackpad issue.

 

[2informaticos]

Didn't check PPVIN_S4_TPAD_FUSE?
Is F4800 OK?

Check U4910 area too.

 

[MegaObi]

u4900 area look good. i tested resistors values around seem good. voltage 3.3 on 1, 5, 8