CDM1550 - Channel Down key progged as Zone Toggle???

The General forum is where users can discuss any topic regarding Motorola communications equipment - hardware, software, etc. There are also several focused forums on this board, so please take the time to ensure that your questions doesn't fall into one of those categories before posting here!

Moderator: Queue Moderator

Post Reply
g8tzl2004
Posts: 1128
Joined: Wed Sep 08, 2004 10:13 am

CDM1550 - Channel Down key progged as Zone Toggle???

Post by g8tzl2004 »

I have a CDM1550 (GM338/GM360) where three front keys - Channel down arrow key , Left arrow key and Right arrow key all act as if they are programmed as a Zone Toggle key. When you press any of the 3 keys, the zones toggle up/down rather than eg channels scrolling in a downwards direct if you press the Channel down arrow key.

There is no option to program other functions to the down/left/right arrow keys...so its not a programming error with regard to the actual key function.

The radio firmware is R05.05.17 and I am using CPS R06.12.05

Maybe its a corrupted codeplug? Or corrupted firmware? Or the flex cable between the head and body need reseating? Or I've not programmed the radio correctly.

Any ideas?

The radio is in mint condition and was manufactured in 2006.
User avatar
kcbooboo
Batboard $upporter
Posts: 2117
Joined: Wed May 01, 2002 9:03 am

Re: CDM1550 - Channel Down key progged as Zone Toggle???

Post by kcbooboo »

Perhaps the control head is dirty or bad? All the pb switches generate two analog voltages based on "row" and "column".

Take the control head apart, make sure the pcb contacts under the silicone buttons is clean. Someone could have poured soda or coffee into the radio. Try another control head. I don't know if any head-specific info is programmed into it, like it is in the Spectra S9000-style head.

Bob M.
Jim202
Posts: 3609
Joined: Sun Sep 09, 2001 4:00 pm

Re: CDM1550 - Channel Down key progged as Zone Toggle???

Post by Jim202 »

You should be able to put a good assortment of selections to pick from to program those buttons. Been a while, so can't provide step by step how to do it off the top of the old brain. But I have made a number of programming changes to those buttons over the years.

Jim
g8tzl2004
Posts: 1128
Joined: Wed Sep 08, 2004 10:13 am

Re: CDM1550 - Channel Down key progged as Zone Toggle???

Post by g8tzl2004 »

Thanks kcbooboo. As you say, its probably better to try a known good head.

There is no option to actually program the down/left/right keys so that they will perform other functions...so the fact that they all operate as if they are Zone toggle keys is odd. I don't even think there is a Zone Toggle option :) I have an MCS2000 with really early firmware and I got a similar sort of effect with the wrong keys being programmed as there was a codeplug mapping issue between the early firmware and later RSS. The CDM is using 2006 firmware...but I have another CDM (40W version) with earlier firmware and the Down/Left/Right keys work OK using the same CPS version..but maybe there was an issue with R05.05.17 firmware but then there would likely be lots of comments on the Batboard about bad firmware :) I've also tried a default codeplug but that had no effect...so its not a corrupted codeplug.
g8tzl2004
Posts: 1128
Joined: Wed Sep 08, 2004 10:13 am

Re: CDM1550 - Channel Down key progged as Zone Toggle???

Post by g8tzl2004 »

You can program 4 front keys (P1, P2, P3 and P4) with numerous options but the up/down/left/right arrow keys are not programmable.

I have programmed P4 as a Down Arrow key so I can use that instead of the actual down arrow key :)
g8tzl2004
Posts: 1128
Joined: Wed Sep 08, 2004 10:13 am

Re: CDM1550 - Channel Down key progged as Zone Toggle???

Post by g8tzl2004 »

The radio is ex-marine so could have been used as an on-board ship low power repeater - so maybe its using some kind of modded repeater firmware which causes the down arrow key to act as a Zone toggle key?
User avatar
jackhackett
Posts: 1513
Joined: Tue Jun 10, 2003 8:52 am

Re: CDM1550 - Channel Down key progged as Zone Toggle???

Post by jackhackett »

For a repeater you'd use two radios and a repeater controller, the accessory pins would be set up for the controller used, and generally there would only be one channel programmed, not much use for zones in a repeater and no modded firmware required. More likely it's a control head issue, if it was on a boat it could have gotten corrosion on the board.
g8tzl2004
Posts: 1128
Joined: Wed Sep 08, 2004 10:13 am

Re: CDM1550 - Channel Down key progged as Zone Toggle???

Post by g8tzl2004 »

Thanks jackhackett.

The CDM radio looks mint so could have been in a repeater enclosure but as you say, why would it have all the on-board UHF marine simplex and repeater freqs and zones programmed rather than just one repeater freq.

I'm pleased that you are now focusing more on radio rather than drink and girls.
User avatar
kcbooboo
Batboard $upporter
Posts: 2117
Joined: Wed May 01, 2002 9:03 am

Re: CDM1550 - Channel Down key progged as Zone Toggle???

Post by kcbooboo »

The control head can easily be taken all apart with nothing more than a plastic prying tool or a small flat-blade screwdriver. After that, clean the carbon trace contacts on the front of the pcb, clean the silicone button assembly and all the plastic parts. I usually wash them in hot water and some dishwashing detergent, then thoroughly dry them out. Everything snaps back in place. Of course if the radio is filthy, cleaning it makes a world of difference.
g8tzl2004
Posts: 1128
Joined: Wed Sep 08, 2004 10:13 am

Re: CDM1550 - Channel Down key progged as Zone Toggle???

Post by g8tzl2004 »

I've checked out the service manual on dismantling the CDM...but can you just remove the plastic front leaving the control PCB and LCD in place attached to the body and then just remove the silicone button assembly to enable the PCB to be cleaned.

Or do you need to remove the entire control head including the plastic "interface" ..and then remove the ribbon cable...then the plastic interface...then the PCB... in order to gain access to the front of the PCB "from the back" to clean it?

The radio is in mint condition but looking carefully around the problem keys there does appear to be some white residue...so I'm hopeful the PCB just needs a good clean.

Does the volume pot knob pull off easily or is it really difficult and requires lots of force?

Thanks
User avatar
jackhackett
Posts: 1513
Joined: Tue Jun 10, 2003 8:52 am

Re: CDM1550 - Channel Down key progged as Zone Toggle???

Post by jackhackett »

To disassemble it you pry between the control head and interface and unplug the ribbon cable from the radio chassis. Then unplug the speaker from the board. The circuit board has some tabs that snap into the housing, it can be removed by carefully prying around the edges with a small screwdriver. You can push on the front buttons to help push it out, but be careful with the screwdriver or else you can damage the LEDs which are near the edge of the board.

The volume knob is snapped into the housing, the pot shaft just fits loosely into it. When you take the board out the pot will stay on the board and the knob will stay on the housing. When you put it back together you have to make sure the D shaped hole and shaft are lined up.

The contacts on the board are gold plated, I clean them with an alcohol wipe. The contacts on the rubber buttons are carbon, you don't want to mess with those if you can avoid it, trying to clean them can ruin them.

The display is snapped into the housing and has sort of rubber and carbon contact strips, again, don't mess with those. You shouldn't have to do anything with the display unless you're going to clean the housing in a sink or something, then you'd have to remove it.

When you put it back together you put the buttons and speaker in the housing, line up the volume control shaft, and press the board back into place. It snaps into place. Reconnect the speaker and ribbon cable (blue dot on cable goes towards 0 marking on radio). When you put the head back onto the radio the board will sometimes pop back out a bit and you'll get segments of the display missing. Make sure it's seated well and then squeeze the head slightly as you snap it back onto the radio to keep the board from popping out. Alternatively you can take the interface off of the radio, snap that into the head and then put the whole thing back onto the radio. That makes it a little easier to keep the board in place.
g8tzl2004
Posts: 1128
Joined: Wed Sep 08, 2004 10:13 am

Re: CDM1550 - Channel Down key progged as Zone Toggle???

Post by g8tzl2004 »

Thanks Jackhackett

is the LCD assembly not soldered to the PCB but just rests on the PCB when everything is snapped together?

The service manual shows a picture of " how everything lines up" with the knob attached to the pot shaft on the PCB...is this wrong...the knob should be attached to the plastic front panel rather than the pot shaft and the pot shaft then slots through the rubber keypad assembly and into the knob when you reassemble?
User avatar
jackhackett
Posts: 1513
Joined: Tue Jun 10, 2003 8:52 am

Re: CDM1550 - Channel Down key progged as Zone Toggle???

Post by jackhackett »

The display sits in the control head housing, it connects to the PCB through elastomeric connectors. https://en.wikipedia.org/wiki/Elastomeric_connector

And yes, the knob snaps into a hole in the front panel. The pot is soldered to the board and it's shaft goes through the rubber keypad and into a D shaped slot in the knob. It's not a tight fit, it will just come out when you remove the board.
User avatar
kcbooboo
Batboard $upporter
Posts: 2117
Joined: Wed May 01, 2002 9:03 am

Re: CDM1550 - Channel Down key progged as Zone Toggle???

Post by kcbooboo »

You can remove the knob first, but it's easier to do after you've removed the circuit board. It has some outward-spreading clips that hold it into the hole in the front panel, and these can easily be compressed from inside if you need to remove the knob. So ignore the knob for now, pry the head off the radio, remove the adapter "ring", unplug the speaker, then pry the board out of the head at the top and bottom edges. You'll see where little tabs on the board are held into the inside of the head. The LCD display is held to the board with plastic clips; leave that alone. The silicone buttons may or may not come out with the board but they should be placed into the control head first, followed by the board, when reassembling.

Bob M.
g8tzl2004
Posts: 1128
Joined: Wed Sep 08, 2004 10:13 am

Re: CDM1550 - Channel Down key progged as Zone Toggle???

Post by g8tzl2004 »

Thanks kcbooboo and jackhackett.

Just so I'm clear, the LCD will stay attached to the circuit board with its plastic clips when removed from the head OR does the LCD stay attached to the head when you remove the circuit board from the head?
User avatar
jackhackett
Posts: 1513
Joined: Tue Jun 10, 2003 8:52 am

Re: CDM1550 - Channel Down key progged as Zone Toggle???

Post by jackhackett »

It stays attached to the control head housing. Just take it apart, you'll see how it all goes.
g8tzl2004
Posts: 1128
Joined: Wed Sep 08, 2004 10:13 am

Re: CDM1550 - Channel Down key progged as Zone Toggle???

Post by g8tzl2004 »

OK thanks
User avatar
kcbooboo
Batboard $upporter
Posts: 2117
Joined: Wed May 01, 2002 9:03 am

Re: CDM1550 - Channel Down key progged as Zone Toggle???

Post by kcbooboo »

I pulled apart, to clean, dozens of CDMs. I took the entire molded plastic control head "housing" to the kitchen sink. As I recall, the circuit board had the display clipped to it. You don't want to remove the LCD assembly because the zebra strips require careful alignment to insure it all works properly. Everything electronic came out with the circuit board, except the speaker that was removed separately.

There IS a disassembly procedure in either the basic or detailed service manual. I'll let you guess where you can find those.

Bob M.
g8tzl2004
Posts: 1128
Joined: Wed Sep 08, 2004 10:13 am

Re: CDM1550 - Channel Down key progged as Zone Toggle???

Post by g8tzl2004 »

Thanks...yes I checked out the basic SM which provides details of disassembly...but, as indicated above, in the "line up" diagrams, it shows the knob attached to the volume pot rather than "clipped" to the front panel...so it did not appear that you could get the knob through the rubber keypad hole!!!

Anyway, I was originally convinced that it was a firmware/codeplug error but you were absolutely right that the circuit board just needed cleaning. Before opening the head, I decided to "work" the down arrow key...I pressed it in hard and with 2 fingers pushed the key to the right and up and down and to the left and up/down...doing this while the key was pressed down hard ...and the key started to work!!! The board still needs cleaning and the key is not always making 100% contact and I sometimes get the Zone toggling when pressing the down key...but it shows that somebody must have spilled soda or something on the keypad. I have had a similar problem with my cordless phone...you get a sort of capillary action and the soda climbs up the back of the rubber keypad!!

The right and left arrow keys act as zone toggle keys by default so it was only the channel down arrow key that was playing up!!
User avatar
jackhackett
Posts: 1513
Joined: Tue Jun 10, 2003 8:52 am

Re: CDM1550 - Channel Down key progged as Zone Toggle???

Post by jackhackett »

kcbooboo wrote:I pulled apart, to clean, dozens of CDMs. I took the entire molded plastic control head "housing" to the kitchen sink. As I recall, the circuit board had the display clipped to it.
Nope, I've taken apart hundreds, the display is definitely clipped into the housing. There are little plastic 'lever' type things on each side of the display that hold against two plastic posts on the housing, you have to carefully press those in a bit if you want to take it out, and the display will tend to stick to the housing a bit so a little gentle prying may be necessary.
g8tzl2004 wrote:Thanks...yes I checked out the basic SM which provides details of disassembly...but, as indicated above, in the "line up" diagrams, it shows the knob attached to the volume pot rather than "clipped" to the front panel...so it did not appear that you could get the knob through the rubber keypad hole!!!
The exploded view in the BSM is misleading, to say the least.

Glad you identified the problem, hopefully it's not a bad carbon pad on the button.
Post Reply

Return to “General Motorola Solutions & Legacy Radio Discussion”