power issue with cdm1250

[jmr3865]

I have a cdm1250. The keypad on the mic is lit but the radio itself is not showing any signs of power. The display is not turning on, buttons have no light. Any suggestions?

[Jim202]

By any chance have you tried to put a watt meter on the antenna jack?

If this is a newly acquired radio, I would make sure that there is a jumper in the accessory connector to ground
the emergency line. If the jumper is missing and the radio is set up for emergency, it will go probably into TX as
soon as the power is applied. This is a software setting in the radio. Most techs jump this pin out to not get
caught up in the emergency mode operation. You never know how the radio was set up.

There is an ignition mode that could cause some problems. In this mode the radio will be looking for +12 volts
on the ignition pin to function normally.

You just need to start looking at the obvious things. Like is the heavy 12 volt feed at the back of the radio
really supplying the +12 volts and not have a high resistance feed.

Jim

I have a cdm1250. The keypad on the mic is lit but the radio itself is not showing any signs of power. The display is not turning on, buttons have no light. Any suggestions?

[fineshot1]

I have a cdm1250. The keypad on the mic is lit but the radio itself is not showing any signs of power. The display is not turning on, buttons have no light. Any suggestions?

Try this little known option. On the accessory connector on the back short pins 7 & 9 together(i use one of those old computor pin jumpers)
and then apply power to the main power connector. If the radio was setup for +12VDC ignition sense on pin 10 this may bypass that. The
radio should now power up. If not there may be in internal problem on the main board. Good luck....

EDIT - forgot to give you the acc conn pinout below

http://batlabs.com/images/cdmacc.gif

[jmr3865]

Thank you. The radio has been installed in 2001, nothing new or changed. The power leads worked fine for the other cdm that we put in it's place. (both radios are set up the same). off to motorola land it goes!

[jackhackett]

probably the reference oscillator, seems to be a common problem in the pro radios, makes them not power up at all. there'll still be power to some parts of the radio (for instance you can measure the 5v on the power switch) which may explain the mic keypad still lighting.