Icom F5021 Aux speaker jack not working

jps1145

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This may be a long shot, but I'm hoping it will be a simple fix.
I have the chase radio in the center console of my Raptor and ran an auxiliary speaker cable to the center dash speaker. I had heard that it wouldn't cause any issues with the chase radio (poor advice as it turns out). After wiring it up it seemed to work, then started to lose volume, and finally quit working. I plugged in a separate, purpose built, auxiliary speaker thinking it may be the cable, or dash speaker, but no luck. I seemed to have torched the internal wiring to the jack on the radio. The front speaker on the radio still works. I called PCI and described the issue. The tech I spoke to had never run into this before and didn't have a solution.
I can send it in to them to diagnose, but there's no guarantee they can fix it (without costing as much as a new radio). My next idea would be to convert that radio into a race radio (by adding the intercom cable) and swap it with the one in my race car. I don't use the aux speaker there.
Anyone run into this or have any ideas?
 

cjohnson

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Connecting to the center console speaker should have been fine as long as you disconnected the truck stereo/CD connections and you didn't have any shorts in your wiring. The center speaker on a Raptor is 4 Ohms. The Icom F5021 can use a 4-8 Ohm speaker so the Raptor speaker is in range.

Could be an easy fix. How handy are you with a soldering iron? The internal wiring to the external speaker jack are traces on a printed circuit card. You would need to jumper the burnt out trace on the circuit card. In order to remove the card you would have to take the radio apart and desolder an antenna connection.

The area circled in red shows where the circuit card trace narrows down. This is most likely the spot where it fried. There is another small trace hidden behind that red power wire that could be fried too. It's hard to tell from the schematic and board layout but it almost looks like there might be a protection resistor or fuse inline with one of the small traces. If that's the case then it might have fried instead of the trace which would be an easier repair.

Frying this out is not good though because it probably stressed the audio driver chip and although it's still working now it might fail in the future. I'd replace the audio chip while I was at it if I was going to rely on this radio.

PCI would recommend a new radio in the case of jumpering fried traces because it is a non-standard repair. Jumpers are not bad, they just don't want to do them because they are time consuming and take more skill. Replacing the whole circuit card would not be cost effective because like you mentioned you can get a new radio for the same cost or cheaper.

Radio.png
 

jps1145

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Connecting to the center console speaker should have been fine as long as you disconnected the truck stereo/CD connections and you didn't have any shorts in your wiring. The center speaker on a Raptor is 4 Ohms. The Icom F5021 can use a 4-8 Ohm speaker so the Raptor speaker is in range.

Could be an easy fix. How handy are you with a soldering iron? The internal wiring to the external speaker jack are traces on a printed circuit card. You would need to jumper the burnt out trace on the circuit card. In order to remove the card you would have to take the radio apart and desolder an antenna connection.

The area circled in red shows where the circuit card trace narrows down. This is most likely the spot where it fried. There is another small trace hidden behind that red power wire that could be fried too. It's hard to tell from the schematic and board layout but it almost looks like there might be a protection resistor or fuse inline with one of the small traces. If that's the case then it might have fried instead of the trace which would be an easier repair.

Frying this out is not good though because it probably stressed the audio driver chip and although it's still working now it might fail in the future. I'd replace the audio chip while I was at it if I was going to rely on this radio.

PCI would recommend a new radio in the case of jumpering fried traces because it is a non-standard repair. Jumpers are not bad, they just don't want to do them because they are time consuming and take more skill. Replacing the whole circuit card would not be cost effective because like you mentioned you can get a new radio for the same cost or cheaper.

View attachment 219153
Thanks for the info! I'm sure my mistake was leaving the dash speaker connected to the truck's system, and it back-fed to the radio. I've since installed a separate small speaker next to the dash speaker.
I can swing a soldering iron, but I may just swap radios with my race car after converting this to a race radio. Can the trace(s) be tested and jumpered without removing the card?
 

cjohnson

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Thanks for the info! I'm sure my mistake was leaving the dash speaker connected to the truck's system, and it back-fed to the radio. I've since installed a separate small speaker next to the dash speaker.
I can swing a soldering iron, but I may just swap radios with my race car after converting this to a race radio. Can the trace(s) be tested and jumpered without removing the card?
Probably not. It's pretty tight and I don't think there is enough room without removing the card.
 

jps1145

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Probably not. It's pretty tight and I don't think there is enough room without removing the card.
I managed to figure it out... while into the radio I was checking connections and jumping a couple connections, i happened to ground the radio chassis to the aux jack ground and heard some sound from the aux speaker. looks like there was a bad or broken connection to the jack ground. i just jumped a wire from that soldered joint to one of the radio chassis ground and viola. Didn't even have to remove the board.
 
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