Maxtrac Audio Question

thgiz · Post by **thgiz** » Tue Dec 11, 2001 4:12 am

Have a maxtrac that appears to have no audio, i have checked it in the RSS and tried both the internal and an external speaker. is there a fuse to protect the audio that may have blown? location? part number? thanks for any and all help...
The Giz

radiotech99a · Post by **radiotech99a** » Tue Dec 11, 2001 5:50 am

Have you checked the volume pot? Have you checked to see if the jumper is in the back on the accessories plug (16 pin)?

raymond345 · Post by **raymond345** » Tue Dec 11, 2001 2:30 pm

The fastest way I test is to trade a
front control head.This only takes a minute.
U may have burnt the audio amp. if your tests
are correct.

Will · Post by **Will** » Wed Dec 12, 2001 1:28 pm

An even faster way to check a Maxtrac/Radius/ GM radio for audio is to use a handset OR monitor pin 8 on the mic jack for low level, 300mv audio. I use a test mic/earphone (from a telephone handset) and it saves a lot of time. This proves the audio up to the top of the volume control. If the audio is ok here then look at the jumpers on the accessory connector, try a different "head" or volume control board, or check the audio amplifier section in the radio. The volume controls do go bad from external force on the knob, like the clip board sliding off the seat and hitting the volume knob on a sudden stop. REMEMBER if someone grounds a speaker lead on the later radios that will usally blow the speaker amp out.
Very handy for testing R1225 repeaters too!

<font size=-1>[ This Message was edited by: Will on 2001-12-12 16:33 ]</font>

thgiz · Post by **thgiz** » Wed Dec 12, 2001 7:20 pm

do belive i have a bad audio amp...part number to replace it? 16 pin radio

Monty · Post by **Monty** » Wed Dec 12, 2001 10:39 pm

Hi:

You may wish to let a Certified Tech
address the Audio Output Stage of the
radio. Its truly a little more complex
than 1 Audio Amp.

It could be a defective Coupling Cap to the
Speaker, or a host of other transistors &
Componets.

Q506 & Q507 comprise the Audio Output
configuration of the Maxtrac ( and to make
things a little worse ( its all Direct Coupled Design. )

Q506 is a 4800869610
Q507 is a 4800869618

You might find its " NOT " the main PA ( Unless you see some burnt componets in and
around the Audio Output Stage.

In my service history, I have only found
a few PA's out of 100's of radios that were
truly defective.

Also, it requires Complete Removal of the
Logic Board to replace them properly.

If you wish, I can fix them for you at a
price about 1/2 of what Motorola charges.

Monty