Changed tristar and passed with tester but still blank screen!

First off, your reply is much appreciated!

Ok, the full story is originally the pad was completely dead and battery was replaced because the connection port had a good “click” when the cable was installed. However the battery didn’t fix the issue but now with a partially charged replacement battery I was able to boot the device and see that cable connection was not recognized. I then changed the port but still not recognizing any cable. Based on this I changed the tristar and now the pad recognizes the cable but will not charge. At this point the replacement battery has gone completely dead.

From what I read this can be pointing to a gas gauge issue. Unfortunately I’m not familiar on that circuit yet.

Thanks for the feedback. In my experience, charge related issues on the iPad air should be attacked in the following order: Charge Port, Battery, Tristar and finally PMIC. Of course, you need to double check your work first (look for dislodged parts) and I would try a new Tristar IC as it may be damaged, defective or improperly installed.

The gas gauge circuitry is underneath the main shield, close to but not right next to Tristar so it is unlikely you damaged it.

Got it!

I did purchase a tristar tester and it passes. If needed can try another chip. the solder work is clean. Took a before and after picture to make sure everything was in place. I'll try the PMIC next.

Thanks again!

Ok, so removing the PMIC was a bit of a nightmare. with my 500W hot air station I couldn't get it to budge and I ended up using a big gun with a small nozzle but I think i over did it because many of the surrounding components turned brown, Any suggestions for future removal of this part?

Now for reinstallation I have to reinstall many surrounding components that were moved but I'm hesitant to use the same gun as removal for the PMIC itself. Again any suggestions there?

Thanks!!

Removing a PMIC is already a difficult repair, using improper tools only makes it worse. I would not use a heat gun for the installation unless absolutely necessary. To be honest, there is already a high likelihood that collateral damage occurred.

Which hot air station do you have? If you plan on doing more micro-soldering work, you should invest in something decent before continuing. If it's a one-off, then you don't have much to lose at this point.