Board-Level Electronics Techs?

[Eagle]

I need help.

 

As some of you may have picked up from other posts, a year and a half ago I picked up a 2001 Cherokee. I admit -- I was seduced by the fact that it's a near twin for my 2000 Cherokee, it appeared to be in decent shape, and it was (for a ten-year old XJ) relatively low mileage (83,xxx at the time). I paid too much for it, and I've been paying ever since.

 

The current problem is the radio. It has the factory AM/FM/CD/Cassette head, and the display illumination is getting progressively flaky. Not the backlighting for the controls -- just the dial. It'll work for awhile, then get dim, then go out -- and a couple of hours or a couple of days later it'll be back ... for awhile. Recently, the no-display intervals have been getting longer and the visible intervals have been getting shorter.

 

When the display goes out, the radio still works and the CD still works. I suspect it's something about the power connection to the LED or LCD display that's flaky but I have no idea how to go about troubleshooting it.

 

Can anyone provide guidance?

[Alexia]

This video has a thorough process of diagnosing these radios. The electrician ends up finding a different radio then goes to the trouble of unsoldering the VFD to get at a replacement control chip underneath it. Even after replacing the chip he finds that it still does not work. So he then builds a new voltage regulating chip to run the display instead.

 

 

The short version: Replace it unless you have lots of patience to replace some chips.

[Eagle]

Did you see the electronics gear he had on that bench? WOW! Impressive. Must be nice to know what you're doing.

 

There's no way I could possibly undertake to go through what he went through. But the video did answer the question of whether or not I could splice in a display from a different radio ... unfortunately, the answer seems to be "No." So much for Plan A.

 

But I think I can handle his Plan B -- just jumper directly from the 12-volt input through a new resistor and power the display directly. If I can source a resistor with those specs from Radio Shack I may give it a try. As he said, I could just toss in an aftermarket radio (and I already have a couple I could use), but I'd rather keep it looking factory if possible.

 

Thanks for finding that video.

[Alexia]

Well, you can swap a working display if you can find a working display.

 

The display in my 1997 stock XJ radio works fine surprisingly. I will be replacing it with an aftermarket radio though.

[dave92cherokee]

Not sure if they're the same but the 97 country i bought last year the previous owner swapped out the radio with one from a durango and said that the connections were the same and it works fine. As for me though I prefer the look, ability, and quality of aftermarket audio over cheap stock audio.

[Eagle]

Well, you can swap a working display if you can find a working display.

 

The display in my 1997 stock XJ radio works fine surprisingly. I will be replacing it with an aftermarket radio though.

 

Swapping the display requires unsoldering a bazillion tiny solder joints. The guy in the video obviously knows how to do that -- I can solder larger stuff, but I know I'm not good enough to do that. But ...

 

The video shows that the display itself wasn't the problem, it was one of the chips that drive the display. So if I replicate his jumper experiment and my display light up, then I should be able to "fix" mine the same way he did, just by soldering in a jumper through a resistor. That I can handle.

 

Dave, I have two Kenwoods new-in-box that I could use. I prefer the factory look, and the factory radio does everything I want. If anybody made a reasonably-priced 1-1/2-DIN replacement I might be tempted, but there were never a lot of those and they now seem to have disappeared from the marketplace. To go aftermarket in a 2001 XJ you have to use a single-DIN head with a 1-1/2-DIN adapter bezel, and I think that looks stupid.

[Alexia]

 

 

Well, you can swap a working display if you can find a working display.

 

The display in my 1997 stock XJ radio works fine surprisingly. I will be replacing it with an aftermarket radio though.

 

Swapping the display requires unsoldering a bazillion tiny solder joints. The guy in the video obviously knows how to do that -- I can solder larger stuff, but I know I'm not good enough to do that. But ...

 

The video shows that the display itself wasn't the problem, it was one of the chips that drive the display. So if I replicate his jumper experiment and my display light up, then I should be able to "fix" mine the same way he did, just by soldering in a jumper through a resistor. That I can handle.

 

Dave, I have two Kenwoods new-in-box that I could use. I prefer the factory look, and the factory radio does everything I want. If anybody made a reasonably-priced 1-1/2-DIN replacement I might be tempted, but there were never a lot of those and they now seem to have disappeared from the marketplace. To go aftermarket in a 2001 XJ you have to use a single-DIN head with a 1-1/2-DIN adapter bezel, and I think that looks stupid.

 

 

I meant swapping the entire front circuit board with the display from a working unit.

[Eagle]

I meant swapping the entire front circuit board with the display from a working unit.

 

Ah, so.

 

There are no u-pull junkyards in Connecticut. The state outlawed them a number of years ago. Junkyard prices for used radios range from $40 to $100, and there's no assurance a replacement (radio or display) would be an improvement. The one I have worked fine for a year, then it became progressively flaky. A replacement could last ten years -- or ten days.

 

If I can "fix" it with a resistor and a soldering iron, I'll be happy.