Radio Repair

[CrawlingCritter]

:attom: I don't know if any of you guys work on electronics, but I thought it was worth asking a radio repair question. I have a '90 Laredo with an AM/FM radio cassette player. The AM radio works fine and the tape player works fine, but the FM receiver works intermitantly. When it does work it works only when the cab is warm. I'm going to pull the radio and take a look for cold solder joints. Anybody else taken one of these radios apart? Got any ideas what else to look for?:helpme:

 

[94XJ2door5speed]

It's really not worth it. Its probably something you wont even be able to replace, If you can even find the problem. Just get a new radio.

 

[Jeepm@n]

I'm no electronics major, but 2 things may be causing this first would be the switch between the FM/AM. There may be a relay downline. Second would be any antenna connection. There are separate lines internally for the FM/AM antenna's. Without a schematic or the board in front of me I cannot help you more then that. I'd purchase some electric contact cleaner and clean all dials and switches. Dials meaning variable resistors.

 

[sharq]

i cant believe you even have the original radio in your '90. do yourself a favor and buy a new one for that thing.

 

[rooneypower]

X2

i agree with tigershark

 

[CrawlingCritter]

Yeah, the antenna is one of those powered things. The jeep had a cheap aftermarket CD player in there when I bought it with lousy reception. I live in the mountains and like to listen to the news, so I thought an OE receiver would be best here. I bought this unit (no warrenty). Just my luck. If heating up the solder joints doesn't work I may try to replace the Xtal. (If i can read the freq and find one from Mouser.):conceited

 

[MoFo]

What is the make and model on the OEM radio? I have the FSM for the factory radio/tape deck in my 87 XJ. If it is the same one, I can let you have the FSM. As for your problem, Antenna problems will first show up on the FM band, because it is much higher frequency. The socket on the radio for the antenna is the exact same size as the bananna plug on most service VOM, DMM (or VTVM) test meters. Just take a meter lead and plug it into the antenna jack and tape it to the windshield as a test. Take if for a drive. If the reception is better, you found the problem.

If the antenna is not the problem, it is actually a blessing that the problem can be truned off and on with cold. Get your self a hair dryer and a can of arasol freeze spray at your local elecrtonics parts store. Warm things up with the general heat, then freeze individual components until you find the problem. If you need spot heat, that is where your pencil soldering iron comes in.

 

[Jeepm@n]

Check your antenna connection at the right kick panel. That is where I've seen more problems for antenna's

 

[xj9687]

x2 on the antenna connection on the right front kick panel i took my whole 96 interior out to fix the floor and found that that connection was broken and not connected the radio didnt work before now it does.

 

[CrawlingCritter]

I picked up another radio from a guy parting our an XJ. This one is only an FM/AM no cassette though. I just put it in and it seems to be working OK. I managed to break the end off of the antenna cable but I stripped back the coax to some good wire and desoldered the old connection and resoldered a new one.
I took the old cassette apart (since I had it out anyway) and discovered multiple circuit boards.:smsoap:


MoFo's suggestion sounds reasonable unfortunately this most of the components are small surface mount stuff and I can't fix that. I did spy some relays in there that might be the culprit.

For me doing things like this is a hobby. Working on my Jeep keeps my mind off my troubles. I'm disabled and so what if its a waste of time? Beats watching soap operas on TV.:confused1