CDM 1550 - Suddenly dead?!?!?

[ve1gln]

OK, it was working...sitting on the bench.

Turned on the power today.... Nothing.... won't turn on....

WTF?!?!

Anyone seen this before? anyone know where to ever start troubleshooting.

Thanks

Glen
VE9GLN

[Jim202]

OK, it was working...sitting on the bench.

Turned on the power today.... Nothing.... won't turn on....

WTF?!?!

Anyone seen this before? anyone know where to ever start troubleshooting.

Thanks

Glen
VE9GLN

Get out the volt meter and start doing all the normal checks. Need the 12 volts on the rear connector. You may or may not need ignition input to the accessory connector depending on programming and jumpers. If you do have ignition feed, check to see if you have 12 volts on the wire after the fuse.

Jim

[jackhackett]

They'll do that if the reference oscillator goes bad. If power supply is okay check on the power switch contacts, should have about 5 volts on one side when not pressed and on both sides when pressed. If you've got that it's probably the oscillator.

[ve1gln]

I do have power coming into the board, I measure 12V at many locations. There is no ignition sense on it, the radio was working on the bench. Turned off the PS for the night, and next day... nada.

I looked for the 5V on the switch, I am not getting any voltage on either side of that switch.

Thanks

Glen
VE9GLN

[jackhackett]

There's a fuse that feeds power to the control head if I recall correctly.. I'll look it up.


edit: There's a fuse (actually a circuit board trace) that supplies constant 12v (A+ from power jack) to the head where it's regulated down to 5v and applied to the power switch.

Check on the flex cable connector in the head, Pin 3 should have 12v (3rd pin from side furthest from speaker connector), if it doesn't you'll need to find the fuse link (it's at different places depending on specific model radio).

Somewhere near the flex cable connector in the radio there will be a pair of empty pads for a chip component with a little loop of circuit trace connecting them, the pads are there so you can put in a chip fuse should the trace be burnt (they call for part #0662057B47).

[ve1gln]

There's a fuse that feeds power to the control head if I recall correctly.. I'll look it up.


edit: There's a fuse (actually a circuit board trace) that supplies constant 12v (A+ from power jack) to the head where it's regulated down to 5v and applied to the power switch.

Check on the flex cable connector in the head, Pin 3 should have 12v (3rd pin from side furthest from speaker connector), if it doesn't you'll need to find the fuse link (it's at different places depending on specific model radio).

Somewhere near the flex cable connector in the radio there will be a pair of empty pads for a chip component with a little loop of circuit trace connecting them, the pads are there so you can put in a chip fuse should the trace be burnt (they call for part #0662057B47).

OK, Strangest thing... I looked around that connector, there was not 12V at pin3, so I figured I had nothing to loose and I applied 12V to it...Nothing... I then applied 12V to pin2 and then pin1. When I hit pin 1 the radio came on, and is now working almost normal... It turns on and off with the knob again...however... I have no display lights and no indicator lights. tx/rx etc etc.....The mystery deepens.

Thanks for all your help on this.

edit: re-reading your post, I got the pins backwards, I went "closest to speaker" so I was on the wrong pin anyway.... but applying power to the pin closet to the speaker seems to have "woken" up the radio....



Glen