CDM1550 that gives self test tone constantly

[Jay]

I've got a CDM1550 that someone brought to me to troubleshoot. All it will do is cycle give the power up test tone sequence, then cycle down and repeat. Swapping a new head on the radio fixes the problem. This was caused by an improperly wired programming cable.

Any idea what in the head could be the cause?

Jay

[Bill_G]

Are the mic jack pins combed out correctly, or did the other cable tangle a couple together?

[Jay]

Yep, the connector is OK. Programming cable was wired incorrectly (pin 1 and 8 used instead).

[Bill_G]

Pooper scoopers. Not a super simple fix. I'll have to look at a schematic to see what goes where.