CDM1250 Scan problem

[firefive76]

Originally Posted by mmckenna

Motorola has a specific tool for removing the heads, but it's just a plastic prying tool. You can do the same thing with a wide blade screwdriver if you are careful. There is the head and there is a plastic mating piece that adapts the head to the radio. Just be careful of the flat ribbon cable that connects the head to the radio. There is some slack, but not a bunch. You can -carefully- unplug the radio end, just make sure you reinstall it the correct way. There is often a black or blue dot on the ribbon cable on one side, and a matching ""0" on the radio body to help with orientation.
Unplugging it from the head side is a bit different. There is a special connector the ribbon cable slides in to. To release it there is a brown side and and a white side on the connector on the head. The brown bit lifts up a little ways and allows the ribbon cable to slide out. When you reinstall it, you insert the cable and push the brown tab back down. The same orientation rules as above apply.

Reassembling is just pushing everything back together. Be careful about not pinching the ribbon cable in the process.

It's actually a pretty easy task to disassemble.


When you get it apart, take a look at the back of the mic connector for a jumper or something like that. Not sure it's the cause of your issue, but it could be.

Tried this overnight, I don't see anything obvious. I also connected a desktop mic to it that has the monitor button and that doesn't work either. It's like the radio doesn't even the off hook at all. Wonder if something could be bad in the head that is shorted out the hook circut?

[SteveC0625]

Originally Posted by mmckenna

Not sure if it applies to the CDM's, but I know on some of the Motorola radios there was a modification that would let them scan without a mic connected. I think you installed a jumper, or maybe it was remove a resistor, in the head to make it do that. Probably would be a good idea to disassemble the head and take a good close look at it to see if anything is out of place.

Not necessary on the CDM's. The older Radius, MaxTrac's, GM300's, etc. needed a jumper between Pins 3 & 4 of the mic connector to scan or hold PL without a mic. That was best accomplished with a jumper in an RJ45 plug rather than opening up the radio. The CDM's need neither as it is all in the software.

I'm not familiar with any jumper or other component on the heads that needs to changed.

However. making sure the flat ribbon between the radio and the head is properly seated is a good thing to check.

[firefive76]

Originally Posted by SteveC0625

Not necessary on the CDM's. The older Radius, MaxTrac's, GM300's, etc. needed a jumper between Pins 3 & 4 of the mic connector to scan or hold PL without a mic. That was best accomplished with a jumper in an RJ45 plug rather than opening up the radio. The CDM's need neither as it is all in the software.

I'm not familiar with any jumper or other component on the heads that needs to changed.

However. making sure the flat ribbon between the radio and the head is properly seated is a good thing to check.

I pulled both ends of the ribbon cable out and reseated them, still no luck. I think I'll just live with it for now. I'm looking for a UHF & if I find one, I'll swap heads and see what happens.

[SteveC0625]

Originally Posted by firefive76

I pulled both ends of the ribbon cable out and reseated them, still no luck. I think I'll just live with it for now. I'm looking for a UHF & if I find one, I'll swap heads and see what happens.

In your Scan Lists, try the following:

Scan List--Scan List #x-->General Tab--Options Section-->uncheck User Programmable and PL Scan Lockout

It's the only variation between yours and mind that I can find.

[mmckenna]

Originally Posted by firefive76

I pulled both ends of the ribbon cable out and reseated them, still no luck. I think I'll just live with it for now. I'm looking for a UHF & if I find one, I'll swap heads and see what happens.

I've got a UHF CDM1550 I'm looking to get rid of. Remote head, high power, etc. PM me if you are interested.

[firefive76]

Originally Posted by mmckenna

I've got a UHF CDM1550 I'm looking to get rid of. Remote head, high power, etc. PM me if you are interested.

PM sent.