Help! Faulty MCS2000

motorolaaustralia · Post by **motorolaaustralia** » Wed Mar 08, 2006 11:24 pm

Hi all,
I have recently bought an Model II Remote MCS2000 UHF Radio. It is quite an early model.

It powers on, gets though self test and all the buttons work fine. Transmit is fine with both power and audio.

The problem is there is no backlight on the display and no receive audio. The is no TX/RX LEDs either.

I have tried another control head and that is not the problem.

Anyone know about this type of fault. I would like to try fixing it myself before sending it to Moe.

Thanks, Dom

fineshot1 · Post by **fineshot1** » Thu Mar 09, 2006 5:25 am

The MCS2000 main body portion of the radio is all constructed on one main board and its almost all surface mount components. You would have to be equipped to troubleshoot and repair surface mount pc boards.

motorolaaustralia · Post by **motorolaaustralia** » Thu Mar 09, 2006 1:13 pm

That's not a problem. I have the whole workshop at my disposal. I just need to know where to start looking!

I will be starting with the various power supply regulators I reckon.

Thanks, Dom

jackhackett · Post by **jackhackett** » Thu Mar 09, 2006 1:32 pm

I seem to recall there being a problem with MCS2000s where one of the regulators comes unsoldered, don't recall the symptoms that causes though.

motorolaaustralia · Post by **motorolaaustralia** » Thu Mar 09, 2006 1:37 pm

Yeah, the regulator comes off the board. But the fault is the radio does not work at all or comes up with an error code. Different symptoms but I will definitely be looking into it.

Thanks.

fineshot1 · Post by **fineshot1** » Thu Mar 09, 2006 2:48 pm

OK - great on the complete workshop. I assume you have the service manual. The only thing I can think to advise you to look for is possibly a common faulty ground point or a bad tantalum cap related to these failing functions or as you said a regulator failure. Good luck

Post by **wavetar** » Thu Mar 09, 2006 3:10 pm

Is there audio when you press the buttons & such? Just curious if you might have a blown audio PA module...possibly among other things.

Todd

motorolaaustralia · Post by **motorolaaustralia** » Thu Mar 09, 2006 5:41 pm

No beeps, no audio at all from the speaker. Mic audio is OK.

I am thinking it is a common voltage regulator for all the faults.

I will sit down and use the service manual to see what I can find.

I just thought I would ask the group to see if it's a common fault.

Thanks, Dom

GlennD · Post by **GlennD** » Thu Mar 09, 2006 6:47 pm

To ask a stupid question. Is the acc plug present?. The DB25 acc connector has a speaker jumper and it must be installed or there will be no audio/

motorolaaustralia · Post by **motorolaaustralia** » Fri Mar 10, 2006 4:15 am

That's a very good point!
I have put in an accessory connector but I am not sure what jumpers are in it. I only assumed it had all the necessary jumpers for the MCS2000 as I have used it before.

I will check that tomorrow!

Thanks, Dom

Post by **wavetar** » Fri Mar 10, 2006 6:07 am

The internal speaker jumper should be between pins 1 & 2. I do believe I have seen your same problem when the audio PA blows in a certain way...it must drag down the voltage from a regulator or something similar. Replacing it has always fixed things for us.

It's also a possibility that the accessory plug has the jumper in the incorrect position I guess, as I have seen very similar issues when the external speaker wires have become pinched & shorted to each other as well.

Todd