Batboard

In the past week we have lost 4 Spectra radios in our patrol cars. They just quit working. Could it be the dreaded capacitor time bombs? If not the caps, then what? Any one out there experience this type of problem? If so, what ended up being the cause? Please share!! We only have 30 more radios left and THEY'RE going fast!

Sincerely

Desperate at PPD

need alot more info than that. quit working could be for many reasons and hard to say without seeing it. what are other symptoms, what is it doing now, dim display, no power at all, no tx, no rx, are they remote mounts, did they have a puff of smoke when they quit? and whatever other info you have.

It would have been helpful to know before I asked for help, huh? I will get the details on each of the radios and get back to you.

Thanks!

OK -- the trouble that we are having with 75% of the radios that we've lost seems to be a synth board problem. The symptoms are -- the radios display the "Out of Range" error, and when you attempt to TX on the radios, there is a high pitched wine (feedback) that is emitted from the radio.

Could this possibly be related to the electrolytic capacitors going bad?

Sure sounds like it could be, especially if they were made before 1996.

The "out of range" message just means the receiver can't hear the trunking control signals. I'm surprised you aren't getting some other real fail codes as well. The feedback could definitely be caused by the electrolyte leaking on some foils and conducting signals "where no man has gone before".

Bob M.

Would it do any good to program in the control channels and see if I can hear them as simplex channels? Or am I just going to get an out of range display?

Rather than do all that, get into the service mode from the control head and inject a signal on each of the test frequencies and see how it does. You can also transmit on them if you hook up a wattmeter and dummy load. Might as well check all you can.

The procedures and frequencies are in the BASIC service manual for the Spectra models you have.

Bob M.

They're like bamboo, they all die at the same time.

Ok, here's the skinny. I have inspected two of the radios so far, and... It’s the dreaded cap problem. They have managed to leak onto the PC board and ruin some resistors on BOTH sides of the board.

I believe the RF board on the first radio is not repairable, but the second one may be saved. I'll know later today.

Well, two down; four to go.

Oh, and lets not forget the other 30 radios that I will now have to systematically go through and replace the caps in before they too decide to leak.

THANK YOU MOTOROLA!!! THANKS; THANKS A LOT!!!!
(Moto: "We have awarded the contract for the capacitors in our new Spectra radios to the lowest bidder.")

Well, at least you confirmed the problem.

I'd expect Will or Bruce to pop in here and offer their repair services.

What are some date codes on the components inside, so we have an idea of the radio's ages?

Bob M.

Where will I find the date code?

Probably on many of the larger ICs on the RF board or command board, but NOT the ones on the microprocessor chips under the MLM. It'll be a 4-digit number, two digits of year, two of week, something lik 9426 (middle of 1994). I would suspect it would start with 9, just because Spectras came out around that time, but a real old one could have been made in the 1980s.

Bob M.

"THANK YOU MOTOROLA!!! THANKS; THANKS A LOT!!!!
(Moto: "We have awarded the contract for the capacitors in our new Spectra radios to the lowest bidder.")
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Unfortunately, this problem goes way beyond Motorola, it's industry wide. A quick search on the internet will reveal that this problem affects all sorts of equipment - usually high end stuff because the cheap stuff has all been tossed away by now anyway.

If you think having a few hundred bucks at risk when your old Spectra dies is a frustration, how about having a Tektronix scope or analyzer die? An instrument like that can cost $20,000.00, $30,000.00 or more. You open it up and there is leakage around every one of those surface mount caps - maybe 30, 40 or more have to be replaced in one machine. Not to mention replacing other damaged components, repairing foils, etc.

THAT'S frustration.

Bob M. I sent him a PM on the 13th.