Batboard

I have a VHF MaraTrac that when turned on, has no display, gives 4 series of 3 short beeps, then a long tone and display shows A1, then silent and no functions. Whats causing this?

It might be set up to use a clamshell control head. Use the head-less powerup trick described in the Batlabs Maratrac page, then read the radio, go into the Control Head option under F2 - Service and see what it's programmed for. You can change it to use the A7 head there.

That's not the problem. Radio worked good for several years and just developed this problem.

Error tone chart says 3 beeps = external EEPROM error.

Try re-programming the radio from a saved codeplug.

You might also look at your logic board. Some logic boards had a Dallas memory chip. These contain a battery and are old enough that some are starting to die. You can replace that chip with a 2816 EEPROM.

If I read the radio it says copyright info corrupted. If I try to clone, it says model number mismatch. The prom I think is 27XX could have been 28XX. I set in another radio and it worked OK. So problem is inside radio.

I may be 'out back' on this one, but have seen a bad DATA line transistor in Maxtrac type Logic boards do the same sort of thing. I look at the DATA line on a scope while trying to READ or PGM. Looking for good square data pulses. With a bad DATA line in the radio, the DATA signal looks all 'mushy'.

It was a bad 2K X 8 eeprom.