Radio Clock Stuck at 1:00 and Radio Frequency Stuck At 98.1 Issue

[H2814D]

Hi all. The 88-94 CDM's with EQ. My model number is 16169561. Has anyone figured out the fix for this problem, other than replacing the CDM? There has to be a simple electronic component failure that is causing it. I've already re-capped the board and re-flowed the most likely solder joints. It is not the head unit. Anyone?

 

[Hipster]

Buy a watch and I hope that's your favorite station. LOL

Just kidding, hopefully someone will be along shortly that can provide some insight.

 

[Eveready]

Recapping is the obvious thing. If it is more involved than that it likely would be best to either send it to a repair service that works on them or if you could buy/borrow a similar radio that you know works you could swap out the components a piece at a time to isolate the module that has the problem. My bet would be a resistor gone high in the head unit but it really would require some serious diagnostic setup to find it Old resistors tend to resist more as they age. A few friends in the antique radio hobby routinely replace every cap and every resistor with modern components. That usually cures the problem. YMMV.

If it were mine I would get some form of aftermarket radio with bluetooth. They make factory like radios that fit in the usual place or if you are cheap like me a center mount works just fine.While you are at it the factory speakers are almost always toast by now so replace them as a matter of routine. Good luck and let us know how it comes out.

 

[Donald Mitchell]

It's the caps in the part under the dash. Some larger ones in there.

 

[H2814D]

It's the caps in the part under the dash. Some larger ones in there.

Mine is a bit different than yours. Mine is from a 1994 K1500 Blazer. I have already replaced ALL of the caps in both the CDM (the box by the accelerator pedal) and the Display Head Unit (with the control buttons). I has to be something else. It is some other component on that CDM Circuit Board somewhere. Radio works fine. Has good sound, the volume goes up and down, the frequencies change, it scans, it tunes up and down, but the display clock and display frequency stay at 1:00 and 98.1. That is the only problem. But just for kicks, I'm on my way to get a watch.

 

[Eveready]

Mine is a bit different than yours. Mine is from a 1994 K1500 Blazer. I have already replaced ALL of the caps in both the CDM (the box by the accelerator pedal) and the Display Head Unit (with the control buttons). I has to be something else. It is some other component on that CDM Circuit Board somewhere. Radio works fine. Has good sound, the volume goes up and down, the frequencies change, it scans, it tunes up and down, but the display clock and display frequency stay at 1:00 and 98.1. That is the only problem. But just for kicks, I'm on my way to get a watch.

Now that is really interesting. All the radios I have seen with the frozen display did not work at all. That is the way mine was when I bought the truck. It would take some serious wiring to swap out the display. Have you tried re-flowing the connections on the display itself? 25 years of bouncing around may have loosened a connection on the display itself. Glad the radio at least works!

 

[H2814D]

Now that is really interesting. All the radios I have seen with the frozen display did not work at all. That is the way mine was when I bought the truck. It would take some serious wiring to swap out the display. Have you tried re-flowing the connections on the display itself? 25 years of bouncing around may have loosened a connection on the display itself. Glad the radio at least works!

I have not done the solder re-flowing on the Head Unit. I was told by the repair facility that the problem is in the CDM. That is the component they want me to send them, if I decide to do it that way. I would rather figure this out on my own though. It is time someone did.

 

[AK49BWL]

The time and frequency is provided by the CDM, so the fact that they're not changing on the display BUT the CDM is still otherwise operating normally .......is still a CDM issue lol. Couldn't tell you which part... There's a possibility the old caps already fried something in an IC on the board before you re-capped.

 

[H2814D]

There's a possibility the old caps already fried something in an IC on the board before you re-capped.

I sure hope not. For some reason the repair facilities are confident they can fix it. That will be my last resort, but I may end up there.

 

[Eveready]

I sure hope not. For some reason the repair facilities are confident they can fix it. That will be my last resort, but I may end up there.

I expect the repair facility collects working examples they have certified and just swaps them out. That way they could guarantee you a working radio. Might be worth it if have to have an original radio. I prefer aftermarket because I think bluetooth hands free phone is a good safety item. Please bookmark the thread and let us know how you come out.