spectra no volume...HELP PLEASE

bulletproof-791 · Post by **bulletproof-791** » Wed Jul 05, 2006 4:53 pm

hello i have a 45 watt VHF spectra.. the problem i have is after i in stall the radio it will work fine for a few days and then loose all volume...then i take it out and leave it sit around for a while and it works again....i have checked the power and ground it is O.K also put a remote kit on it and it does the same thing....can someone please let me know what you think it could be and can it be possibly fixed???.................thanks in advance SCOTT

kb0nly · Post by **kb0nly** » Wed Jul 05, 2006 5:55 pm

Sounds like the typical results of bad caps in the radio. Probably sitting in the vehicle with the temperature extremes during the day is affecting the caps, sit it in the house for a while and it comes back to life, etc.

I had a UHF that did something similar, except it would not only lose audio but the PTT wouldn't work. I would get frustrated with it and toss it on the shelf for a day or so until i had time to come back to it and try again, then it would work fine so i would leave it on the workbench running for a while until it acted up again, etc.

Replaced all the caps in it and it behaved itself for a few months until i sold it, the last i heard it's still working fine.

apco25 · Post by **apco25** » Wed Jul 05, 2006 9:17 pm

typical spectra disease!

kb0nly · Post by **kb0nly** » Wed Jul 05, 2006 10:28 pm

Spectra Electrolytic Degradation Syndrome

motorola_otaku · Post by **motorola_otaku** » Thu Jul 06, 2006 8:54 am

Okay, how 'bout this: a Spectra loses RX audio, but the volume set and button press tones still work fine. I know all about leaky caps on the command board causing complete loss of audio, but this one is new to me.

kb0nly · Post by **kb0nly** » Thu Jul 06, 2006 9:26 am

Perhaps the beep source is still making it to the audio amp but the receive audio isn't due to a bad cap?

I don't have the schematics in front of me to check the audio paths.

Larry Page · Post by **Larry Page** » Thu Jul 06, 2006 11:50 am

I have a remote mount Spectra whose capacitors failed a few years ago before we understood this phenomenon quite as well as we do today. First to go was the volume set and button press tomes, followed later by receive audio.

Exact symptoms develop depending on which capacitor(s) fail first and where the electrolyte chooses to go. (And honestly, it can sometimes be a completely different problem.) For instance, one failure I dealt with had the radio caught in a perpetually repeating power up cycle.

But the capacitor problem is common enough that it's almost always worth checking for early in your diagnostic process.

Regards,

bulletproof-791 · Post by **bulletproof-791** » Thu Jul 06, 2006 12:06 pm

can it be fixed?? and who can do it?

Larry Page · Post by **Larry Page** » Thu Jul 06, 2006 12:09 pm

Several folks on this board can fix this problem if it hasn't been working so long that the electrolyte has destroyed traces on the board. It is very important to get the repair made as quickly as possible.

And any reputable and skiller Motorola shop that does component level repair should also be able to do it. Repair involves surface-mount soldering of very small components.

racerman1cars · Post by **racerman1cars** » Thu Jul 06, 2006 12:25 pm

Mine did the same. Will fixed it it works great now. Will is on here!

bulletproof-791 · Post by **bulletproof-791** » Thu Jul 06, 2006 12:31 pm

if you know anyone PLEASE let me know..the problem started a few weeks ago

kc7gr · Post by **kc7gr** » Thu Jul 06, 2006 1:03 pm

bulletproof-791 wrote:if you know anyone PLEASE let me know..the problem started a few weeks ago

I'm one of the folks, Will is another, and I think there's one more. If the problem only started in the last couple of weeks, there's a good chance the radio can be saved. The choice of techie usually comes down to individual backlog, or geographic preferences.

I'm in Washington state, southeast of Seattle. Will is, if I recall correctly, in southern California. I have a backlog of three repair jobs at the moment, so it'll be about two weeks before I'm free again.

If you decide you want to send the beastie to me, you need only drop me a PM.

Alternatively, if you're comfortable doing surface-mount component rework, cleaning PC boards and solder pads, and you have the tools, workspace and skill to do so, I will be happy to provide guidance.

Keep the peace(es).