CDM1550 UHF will not turn on

[radiocat37]

I have a CDM 1550 UHF 403-470 will not turn on. AAM25RKF9AA5AN. I am trying to fix for a friend. I have 12V power up to the control head on pin-3 ribbon cable connection but at a loss on where to go from here. Any advice on where to start or likely scenarios.

[Jim202]

I have a CDM 1550 UHF 403-470 will not turn on. AAM25RKF9AA5AN. I am trying to fix for a friend. I have 12V power up to the control head on pin-3 ribbon cable connection but at a loss on where to go from here. Any advice on where to start or likely scenarios.

You might try looking here for some info.

http://www.batlabs.com/htpro.html

[MotoFAN]

Firstly connect Ignition Sense wire.

[SteveC0625]

Firstly connect Ignition Sense wire.

+1

For the OP, apply 12vdc to pin 10 of the accessory connector. It is possible that someone programmed the radio to follow Ignition Sense only. Bad move, IMHO, for exactly the reason you may have encountered. Once you get the radio running, change that to Ignition Sense and On/Off in the CPS right away.

As referenced above, pin-outs and all that good stuff are on batlabs.com

[radiocat37]

I did the ignition sense wire. That was one of the first things I did.

[SteveC0625]

I did the ignition sense wire. That was one of the first things I did.

Without sounding too sarcastic, I suggest that perhaps you could tell us what other things you have tried to get this radio running. We all want to help, but it's only fair that you give us a fuller description of this situation so that we don't offer solutions that you've already tried.

[radiocat37]

I looked through past posts and checked voltage at pin 3 on ribbon cable. It was good on the head side.That is as far as I have been. I am knowledgeable to a point on many radios but the waris series I am not and I don't have a service manual. I just don't know from beyond that. So maybe some test points for voltage present? Thanks.

[SteveC0625]

I looked through past posts and checked voltage at pin 3 on ribbon cable. It was good on the head side.That is as far as I have been. I am knowledgeable to a point on many radios but the waris series I am not and I don't have a service manual. I just don't know from beyond that. So maybe some test points for voltage present? Thanks.

Fair enough.

Did you push the volume knob in? On the CDM's, that's the on/off, not a turn clockwise or counterclockwise. Sorry to hit the absolute basics, but I can't tell you how many times the obvious has been overlooked by all of us at one time or another.

Basic Service Manual (2.3 Mb.): https://drive.google.com/file/d/0BxAVX2 ... sp=sharing

Detailed Service Manual (28.7 Mb.): https://drive.google.com/file/d/0BxAVX2 ... sp=sharing

[radiocat37]

Tried the push power button for turn on and nothing. What I was hoping for was some known problems or issues with a "no power on situation" beyond the ign sense and forgetting the powerbutton. I think one thing I need is a known good control head. I locate one and try that. But again all other suggestions and where to start tracing welcomed

[wa6ylb]

If the radio was programmed to use ignition sense, there still may be an issue with the ignition sense line. Inside the radio, the ignition sense
line goes through a very small 470 ohm resistor. This resistor acts like a fuse, and if blown, and you radio is looking for ignition sense,
the radio wont turn on. If your capable of taking the radio apart, the resistor is located just behind the dual headder socket, where the rear
accessory jack is located. There are several chip resistors there. If the resistor is blown, there will be a small hole in it, where it released
the tiny amount of smoke the factory packed into it. An ohm meter will confirm this.
B.

[Andreas]

You should try to dump in a new firmware with the US Waris Lab Flashkit.
Often the FLASHROM has corrupted firmware inside or it is defect.
If the bootloader is completely loaded into the radio and then you get an error message,replace the FLASHROM.

Andreas

[fineshot1]

I seem to recall on the CDM series accessory connector pins 7 and 9 if you short them
and apply power to the main power plug this is an Emergency Power up or something
like that. Someone correct me if i am in error please.

[jackhackett]

CDM series does have a known problem that will cause them to not power up at all, while still having power to the control head. What happens is that the reference oscillator goes bad. This oscillator also supplies the clock signal to some of the micros, and when it quits the radio won't do anything.
I check for it by using a service monitor set to the frequency of the oscillator (16.8MHz if I recall correctly) and then use a cable with a sniffer probe to check near the oscillator for signal. Also sometimes a bit of freeze spray on the oscillator will sometimes make it work for a short time, just long enough to confirm that that's the problem.
Unfortunately if that is the problem the part is listed as "not field replaceable".

[RobinsonK]

All Motorola "Waris Prof Mobile" with the same error. I worked for Motorola Germany for many years. Now I am retired. In Germany, Motorola published internally that the frequent "will not turn on" error is caused by a defect in the flash chip in which the firmware of the device is located. It is the AT49F040 4 MEG chip. All devices could be repaired by changing the chip.