Question about Motorola AXU4100 (10 Channels) 2-Way Radio

2 Answers

Shuts for no reason

Lately our radios shut off for no reason. the volume knob is on but no screen or sound. completely off

Posted by on

2 Answers

  • Level 2:

    An expert who has achieved level 2 by getting 100 points


    An expert that got 5 achievements.


    An expert whose answer got voted for 20 times.


    An expert who has answered 20 questions.

  • Expert
  • 123 Answers
Re: shuts for no reason

Check for any rust or corrotion on radio battery contact. dirty bat. contact could produce this kind of syntoms. What happend if the radio turn off by itself and you try to turn on again? does it turn on normaly?

Posted on Sep 14, 2007

  • Level 1:

    An expert who has achieved level 1.


    An expert who has answered 20 questions.


    An expert that has over 10 points.

    Problem Solver:

    An expert who has answered 5 questions.

  • Contributor
  • 20 Answers
Re: shuts for no reason

Check the battery first..... alot of times a person will put a battery in a chager and let it sit. They will think the battery is fully charged but it may not be... In those battery packs there are a bunch of smaller batteries all tied together. Alot of times these commercial raios will run off of around 7 volts ( check the battery). The battery will only charge up to 7 volts if all the cells inside the battery are good. What I'm saying is for you to charge the battery up fully..... check the voltage listed on the battery then use a volt meter to check the voltage after the battery is fully charged. When a battery has just finished being charged usually it will be overcharged.... a 7.5 volt battery will be up around 8.5 volts for example. So check the battery right after its charged... expect it to be overcharged. If it seems OK, put it in the raio and key the radio for a bit to try and use up some battery power.... then check it again and see if it has dropped drastically. Your problem has to do with power... the first link in the power chain is the battery... check that out... then go to where the battery makes contact with the radio and make sure thats good.... inside the radio there will be a fuse but if thats blown you will get nothing... then the power goes to the switch. Battery... contacts...fuse... switch... that how the power initially gets into the radio. Most of these problems are battery related so I would check that first. If the battery does not have enough power when you transmit with the radio the radio will shut down.... turn off. If its not getting enough current the voltage will drop and once it gets low the radio shuts off. Usually with commercial stuff you will hear a "beep" when this happens. Your problem might be power related... theres alot you can check.

Posted on Sep 14, 2007

Add Your Answer

0 characters

Uploading: 0%


Complete. Click "Add" to insert your video. Add


3 Points

Related Questions:

1 Answer

Will not adjust radio volume

what is it? Not all radios use knobs, but push buttons wheels, etc to adjust sounds.

Jun 12, 2015 | Two-Way Radios

1 Answer

Can't turn one unit off when I turn the volume allthe way down I get no click and the unit stays on

Unfortunately, your volume potentiometer (the part behind your volume knob, which connects to the component board, has gone bad. This can happen from turning the knob too far past full volume or even sometimes when turning it off. The part to repair this has never been offered as a replacement part. Your only solution is to remove the battery to turn the unit off.

Best regards.

Dec 07, 2012 | Motorola Talkabout FR60 (14 Channels)...

1 Answer

I want to take the radio apart, but the antenna and turn on/off knob will not come off. How does the antenna and turn on/off knob come off on a T7400, T7450

Antenna is fixed and attached to the housing. The front and back housings must be first removed to get to it. The volume knob will pull straight up and off the volume potentiometer shaft. This is risky because the small clip which holds the knob in place usually gets stuck on the shaft and then you run the chance of not getting the knob to stay back on the radio.

Best regards.

Apr 07, 2011 | Motorola Talkabout T7400R (2 Pack) (7...

1 Answer


The on/off/volume potentiometer is a common failure part on most radios, including the XTN. The only solution is to have the radio repaired. Typically this style unit can be repaired for $69 flat rate.

Sidenote: On the XTN it is best, when turning on the radio, to turn the knob to at least 50% volume before turning it back to your desired setting. This helps with the initialization of the radio. Also, it is best not to run this style of radio at full volume, as it can cause other receive issues down the line.

Best regards.

Sep 22, 2010 | Motorola XTN 2-Way Radio

1 Answer

I have new batteries, but the charger is steady red, but the radios won't turn on.

Steady red on the charge indicates the battery is charging. This would not be unusual, as the charge will revert to a trickle charge and have a constant red even after a complete charge cycle. For a brief time when the initial charging is done it will be green, but you'd have to be watching the charger pretty closely to catch it green. (Be careful to have the radio shut off when it is placed on the charger, and especially careful to NEVER press the PTT when it is turned on and charging.)

When you say the radio won't turn on, we are assuming you see no light on the radio. If this is the case, you might check the battery connection to the radio and be certain the battery contacts are not flattened or damaged between the radio and the battery.

You might also check your on/off/volume knob in different positions to see if the volume potentiometer has gone bad. If so, you might have intermittent function of the radio depending on the position of the knob.

Lastly, you might try a different battery on the radio to see if it will work with a different battery, maybe the new battery is not functioning correctly.

Flat rate repair is available for this style radio for around $95.

Best regards.

May 22, 2010 | Motorola For RADIUS P110 7.5v 1200mAh NiCd...

3 Answers

Sqeal when talk button is pushed

Two known causes of squealing when the radio is put under a load (such as when the PTT is pressed) are a low or bad battery, or being too close to another radio.

Apr 21, 2009 | Audiovox 2-Way 14 channel FRS Family Radio...

3 Answers

How can I increase the volume of the radio

Check the grill in front of the speaker area for debris or plugged holes. Check the transmitting radio for debris blocking the mic hole. When turning volume up on the radio, do not max out the volume knob, back it off slightly for best sound. If these do not help, your radio is probably malfunctioning and needs replaced.

Jan 03, 2009 | Motorola Talkabout T5100 (14 Channels)...

1 Answer

My vertext standard vx-424 when i tap the turn on knob the radio shuts off then back on

You have either a bad volume potentiometer or a bad solder connection to the component board. The radio is in need of repair.

Dec 08, 2008 | Two-Way Radios

1 Answer

How do I set my sx700 radio to work with hands-free headsets? Any assistance would be appreciated.

Hands-Free Use With Accessories (VOX)
You can transmit hands-free with the use of optional accessories. Once
VOX is turned on, the radio detects your voice and transmits when you
1. Turn the radio off and plug the VOX accessory into the accessory
2. Turn the radio on. VOX shows on the display.
3. Adjust the volume appropriately by rotating the volume knob . Lower the volume
before placing the accessory on your head or in your ear.
4. To turn off, simply remove accessory.
Note: There is a short delay between the time you start talking and
when the radio transmits. There is a short delay before the
transmission is completed.

Owners Manual:

You must be using a VOX capable accessory. Generally this is an accessory without an in-line PTT.

Dec 03, 2008 | Motorola Talkabout SX700 2-Way Radio

1 Answer

Volume programming

Not possible without disabling the speaker.

Jun 20, 2008 | Motorola Two-Way Radios

Not finding what you are looking for?
Motorola AXU4100 (10 Channels) 2-Way Radio Logo

263 people viewed this question

Ask a Question

Usually answered in minutes!

Top Motorola Two-Way Radios Experts


Level 3 Expert

1640 Answers


Level 3 Expert

3018 Answers

bill tarkulich

Level 1 Expert

31 Answers

Are you a Motorola Two-Way Radio Expert? Answer questions, earn points and help others

Answer questions

Manuals & User Guides