gme tx 4200 no manual what does it do

have you tried the GME site?

don't know if this helps
Eprom Error
goto to post 18190

Download the manual at GME website

It usually means the EEPROM chip in the radio (stores all the info like memory channels for scan etc.) is corrupted/damaged. From experience,in most cases the radio will work OK but will not "remember" anything eg. last channel, scan/quiet memories.
But in extreme cases I have seen weird things like channels in hexadecimal with letters A to E, more than 40 channels etc.
You could probably get it fixed, it's a fiddly job as the chip is a surface mount type, and then it will need to be programmed with the TX4200 software. But in the end, you still end up with an old radio, best put a little more money together to buy a new one.

I believe that the TX4200, like the TX4000 is programmed via the microphone socket. On My TX4000 you can get all this weird stuf by shorting certain michrophone socket pins - can also get a channel 25kHz below channel 1.
Just a thought, the microphone plug or cable may be faulty so remove it then re-power up the unit.
Cheers, Tony.