Radius GM900 (MCS2000 variant) crashes after programming - any ideas?

[codefoxed]

Hi folks,

I have a pair of Radius GM900 UHF units on the bench, both type MR503B, model M01RFK9AN3BN. One has a black serial number label, the other white. Unfortunately the unit with the black label (304IWG serial number prefix) has a fault...

When I program it with DOS RSS, it'll read or program OK -- once. After that, the radio completely locks up and I have to power cycle it to recover. RSS reports a timeout, and the control head and power button are completely unresponsive.

This means that making changes to the radio settings involves reading the radio, changing the settings, then cycling the power by pulling the plug and programming it.

The white-label radio (304IXW serial number prefix) seems to work fine. I can read and reprogram it to my heart's content.

Both radios seem to work fine when they're running.

Seems I might have a hardware fault -- has anyone seen anything like this before on a GM900 or other MCS2000 platform radio?

Cheers,
Fox