Roland A 80 LCD screen

I have a Roland A80 controller and the LCD screen is very dim. I purchased what was advertised as a “plug and play” unit off of reverb. The screen came with a cryptic instruction on the box to " plug in here". I spent all day taking the A 80 apart and installed the screen. After installation, the unit wouldn’t power up so I took the inside apart again and plugged everything back in. It powered up but the screen is just as bad as my original screen. It is very dim and you can just barely read it. The seller’s solution is to say that I somehow caused his screen to not display properly. He then came up with a solution to take out jack b board and change the transistor. I can’t do that as I would be changing the A 80 internally to accommodate his screen that may or may not work. Please advise here. Should I purchase a new Toshiba replacement from china and try to get my money back or try putting the original back with a new backlight. the A 80 is not worth much as it is heavy and old. If anyone has any solutions would be very appreciative. Thank you

I know my reply is very late since I just joined this forum. If it was me, I would get my money back.
I have a A80 as well that I did a total referb on after dealing with a seller who sold me one along with a bunch of B.S. on the condition of the unit. The screen was part that job. I would be interested to know what the outcome was. Do you still have the A80 I might be able to help.