AEW10AJS1 ac digital panel keeps climbing to its max of 86 degrees. i cannot operate any of the buttons except the temp down. i have to hold it down because the unit keeps climbing back up to 86. its a losing battle!

Greetings!
I have the same model. Symptoms: Unit works great, Expect..when operating the menu buttons, they do don work properly. Example, pressing the up temp works great, but when pressing the lower temp button, the temp will go to 86 degrees F.
The problem is the control board. I took it out, clean it well with soapy water, rinsed with clean water, blew dry, took a tooth brush with alcohol and rebrushed again, rinsed with water, blew dry with compressed air.
Upon close inspection with a magnifying class, you can see the top of the board connections, did not solder well when manufactured. This is a hint... My problem was with R32 a 0804 resistor not being soldered properly during manufacture.
I replaced the resistor an all is well.

All the buttons have ground at the bottom of the switches, while the top is 5v volts dc with a standard meter, but I do believe all the keys are multiplexed, as seen when pressing one of the buttons, the display may show a different function changing.
Thus the most likely problem, will be with one of the 10K ohm resistors associated with one or more of the buttons. The resister is black in color with 103 written on the top, and is a 0804 size.
Hope this helps.
PS I have found no replacement of the control board, so I just fixed mine. If you have electronics friend, he/she might like the challenge.