Those Military surplus radios are actually Military STOLEN radios. When they were stolen about 10 years ago, some camera shop in New York were selling some of them on eBay. I bought one, unknown they were stolen Military property. I found out they were stolen when NCIS (yes just like the TV show of the same name) when 2 NCIS agents showed up at my door! Ding-dong goes my doorbell, looked at my backdoor camera and seen a woman at the door and a guy hiding where only the security camera could see him. He had a gun clearly visible on his side hip. I yelled through my door “hello”, the lady’s response was “this is NCIS, I need to talk to you now!”. I let them in and that’s when I found out I bought stolen Military property on eBay. I was interviewed for well over an hour and they took the radio and everything that came with it. NCIS was fairly informed about these stolen radios, but not completely informed. These radios had options H02 and H04 (remote stun and remote kill). These NCIS agents kept asking about the iButton which is used to un-stun radios that have been stunned. I didn’t get this iButton with the radio.
What NCIS was misinformed about these radios was the H02/H04 options. They thought these radios could stun or kill other Military equipment like radars, air craft carriers, you name it! Needless to say, they confiscated the XTS2500 and gave me a receipt for everything they took. I still have this receipt. Paid $850 for the radio, and now I had nothing.... Fast forward 6 months, I checked my paypal account and the $850 was refunded!! Wow, I was shocked because that was well past their “refund time frame”. I didn’t request this refund, but over joyed getting my money back.
There were many people like myself who got visited by NCIS and had their radios confiscated. One guy, I believe, in the state of Washington went to his local TV station about stolen items being sold on eBay. This TV station aired a special report about stolen items being sold on eBay. This video may still be on YouTube.
To the OP, that dim keypad also contains the radios AES-255 UCM. If you replace it with a normal keypad, you loose the AES-256. I would research if NCIS is still hunting down these stolen radios before spending any money on a different keypad. The dim keypad and display are 3 SMT resistors that need to be changed to bring it back to normal brightness, including the top red/green LED. Sorry, I don’t have any info what resistors need to be changed.
Good luck