820-01521 trackpad tracking glitchy

[grmacs]

Mouse tracking is sometimes unresponsive but sometimes works normal but it is consistently noticeable that it isn’t working correctly.

This acts like a bad trackpad or cable but I tried both from MacBook that work normally and issue persists. I also connected external mouse and works normal so I know it’s not just lagging or something. I don’t recall ever seeing this and have it be logic board related. Seems like logic board is usually either works or doesn’t.

have you seen this before? Any tips?

 

[2informaticos]

Try with known good battery.

 

[grmacs]

Ok. I think we just installed a new battery but I can try another. Would wired mouse not lag but trackpad possibly due to battery? Is this because trackpad is more of power hog would it matter if plugged in lot charger or not?

 

[2informaticos]

From experience, bad batteries can cause weird trackpad behaviors on MacBook.

 

[grmacs]

Ok. Different new battery and I tried some other old batteries and same behavior

 

[2informaticos]

How the problem appeared?
Clean trackpad connector.
Check all the components from "Trackpad Level Shifting" circuit and rest of page 56.

 

[grmacs]

SOLVED

Thanks! L6703 was visibly distorted. Replaced and trackpad is working normally.