895xlt humming

[danesgs]

I haave an Uniden 895XLT humming issue that starts up when it gets warm, squelch then stays open. Found a cracked solder joint on the AC adapter input but this would not jive with the problem. Anyone seen this before with this model?

 

[RFI-EMI-GUY]

I haave an Uniden 895XLT humming issue that starts up when it gets warm, squelch then stays open. Found a cracked solder joint on the AC adapter input but this would not jive with the problem. Anyone seen this before with this model?

Bad wall wart?

Do you have anything plugged into the external speaker jack?

 

[danesgs]

Nope nothing in the ext. jack. The wall wart has run other 895XLT's with no issue. It takes about 6 minutes to get warm enough for the radio to lock up even on the WX channel and the audio is then pure noise like a connection is going south with the heat. Its all the internal speaker being used. Turning the radio off and letting it sit for 5 minutes gives you another 4 minutes of working then the same occurs again. Just wondering if anyone has had this happen. Pretty sure its a craked solder joint as I already found one but not sure its the right one.

 

[RFI-EMI-GUY]

Nope nothing in the ext. jack. The wall wart has run other 895XLT's with no issue. It takes about 6 minutes to get warm enough for the radio to lock up even on the WX channel and the audio is then pure noise like a connection is going south with the heat. Its all the internal speaker being used. Turning the radio off and letting it sit for 5 minutes gives you another 4 minutes of working then the same occurs again. Just wondering if anyone has had this happen. Pretty sure its a craked solder joint as I already found one but not sure its the right one.

I would try to find the internal voltage regulator(s) and see if any are failing. Sounds like a voltage might be drifting high.

 

[danesgs]

Good Idea. thanks

 

[tvengr]

I would check for a bad filter capacitor in the internal voltage regulator. Bad electrolytic capacitors can change value as they heat up. It could also be a decoupling capacitor on a power supply bus. I would suggest getting a can of refrigerant spray with a spout. When you spray the defective component, it will cool down and the scanner will function again. It could also be a bad solder connection on the scanner circuit board. Bad solder joints show up after about 10 or 15 years.

 

[danesgs]

Thanks, will check all.