After cloning transmits only once

Here is a link to the RDX series page at Motorola, in the lower right corner there is a link to the user guide for your RDU2020 radio. In the user guide there is a very good explanation of matching the XU2100 to the RDU2020. The RDU radio was the next model in line after the XU2100 and was designed to work with it. http://www.motorolasolutions.com/US-EN/Business+Product+and+Services/Two-way+Radios/On-site+Business+Radios/Discontinued/RDU2020_US-EN

sounds like your batteries are shot and not able to supply enough power for transmit

Variety of issues possible. Might need more info. One possible problem is a stuck or bad PTT button

The ACTUAL problem is your rechargeable batteries have most likely depleted over time, and since it takes more batterie power to transmit than to receive it can appear that your batteries are fully charged and you can be receiving but due to the batterie it will be unable to transmit

It means the PTT switch button gets stack or damage that's why other keys are not working.

If this PTT switch is useful for you, you need to consult a mobile service shop near you for a switch replacement. BUT

If this is not helpful, you can remove it by yourself. just follow this procedure.
(You need a T6 precision screw driver or any tool that can release the screw and a soldering iron to remove the ptt switch)

1. remove the battery cover and the battery pack.

2. release the 4 screws located at the upper portion at the back.

3. remove the plate cover.

4. there are 2 flex connector at the top which lcd is connected and at the bottom which keypad/simcard is also attached. Also the anthenna and the camera is insert prior on the location.
Release them with care.

5. lift up the entire board module.

6. locate where the PTT switch is attach (right side when facing the front phone) then remove it with care by using a soldering iron until the 4 connector of the ptt switch is remove.

7. now assemble the phone and be guide with the pattern on how it was dismantle.

Now check it if other keys is working now, please reply if there is still a problem

good luck... and thank you for visiting Fixya.

In order to get the most out of your new radio, read this reference guide completely before attempting to operate the radio.

Turning the Radio On and Adjusting the Volume

1) Press and hold the key to turn the radio ON.

2) To change the volume level press the volume/monitor up or down key to increase or decrease the volume level.

3) Press and hold the key to turn the radio OFF.

Adjusting the Sound (Key Beeps)

Your radio emits a beep each time one of the keys (except for the PTT button and call key) is pressed.
The sound of the Key Beep will increase or decrease depending on the volume level setting.

To turn OFF this beep:

Press and hold the call key while turning ON the radio.

To turn ON this beep:

Turn the radio OFF and ON again.

Choosing a Channel

Your GMR325-2 radio has 22 channels you can use to talk to others. In order to speak to someone,
each of you must be set to the same channel.

To choose a channel:

Press the channel/scan up or down key to increase or decrease the channel number displayed.

Channel Scan Feature

Your GMR325-2 radio has a channel Scan feature that allows you to easily Scan all 22 channels. When an active channel is detected, the unit will pause on that channel until the channel is clear. Then after a 2 second delay, the unit will continue scanning.

Pressing PTT button while the Scan is paused on a channel will allow you to transmit on that channel.

To turn ON channel scanning:

Press and hold either the channel/scan up or down key. The channel number on the display
will rapidly cycle through the channels.

To turn OFF channel scanning:

Press either the channel/scan up or down key.

Talking on Your Radio

To talk to others using the radio:
1) Press and hold the PTT button and speak in a clear, normal voice about 2-3 inches away from the microphone.

While you are transmitting the tx icon is displayed. To avoid cutting off the first part of your transmission, pause slightly after pressing the PTT button before you start talking.

2) When you are finished speaking, release the PTT button.You can now receive incoming calls. While receiving, the rx icon is displayed.

Transmitting a Call Alert Tone

Your GMR325-2 radio is equipped with a call tone that will be transmitted when the call key is pressed.

To transmit the call alert tone, press the call key.

The tone will automatically be transmitted for a fixed length of time.

Auto Squelch Feature

The GMR325-2 is equipped with an automatic squelch system which shuts off weak transmissions
and unwanted noise due to terrain conditions or if you have reached your range limit.

Monitor Mode Feature

Your GMR325-2 radio allows you to listen for weak signals on the current channel at the press of a key.

To turn ON monitor mode:

Press and hold the volume/monitor up or down key. The rx icon will blink.

To turn OFF monitor mode:

Press the volume/monitor up or down key. The rx icon will stop blinking.

Automatic Power Save Feature

Your GMR325-2 has a unique circuit designed to dramatically extend the life of the batteries. If there is neither transmission nor an incoming call within 2 seconds, your radio switches to the Power Save mode. The radio is still able to receive transmissions in this mode.

KEYLOCK ON/OFF

Press and hold the call key until the "L" appears. After 1 second, the LCD will return to the channel display.
To exit Keylock on mode, press and hold call again.

Note: While in keylock on mode, it will still receive transmissions.

ROGER BEEP

Roger Beep is a BEEP that is sent to notify the end of transmission.
Roger Beep can be heard through the speaker when Key Beep is on.
Roger Beep is transmitted even if key beep is turned off. However Roger Beep will not be heard from the speaker.

To turn OFF Roger Beep: Press and hold the channel/scan up Key while turning on the radio.

1) You possibly have a bad or nearly dead battery. Transmit takes more energy than receiving. With this in mind, your radio's transmit will fail, if you have a poorly charged or bad battery, when pressing the PTT. Try a battery from a known good radio to see if it eliminates the problem. If so, replace your battery.

2) The radio is either programmed incorrectly or in need of repair. If you have been experimenting with the programmable features, we suggest you walk back through the steps of programming. Here is a link to the user guide: http://www.mytoolstore.com/motorola/rdx_userguide.pdf Programming instructions begin on page 36.

3) If in need of repair. Radios less than one year old should be under warranty, barring any physical or water damage to the unit. Contact the place of purchase or Motorola for warranty instructions.
If the radio is more than one year old you can get it repaired at any dealer offering Motorola repair. (approx. $85 flat rate)

Best regards.

Cloning Procedure:
(The content of radio A is to be duplicated into radio B)
1. Turn off radio A and turn on radio B.
2. Connect the cloning cable (NKN6376A) to the Universal Connector of both radio A and radio B.
3. Place the PL switch on radio A to the carrier squelch position for full cloning, or the PL position for partial cloning. Full cloning will duplicate the content of radio A to radio B, except for the deviation and squelch settings. Partial cloning is recommended due to deviation variations from radio to radio. (Later version MT1000's (B model for 6, 16, and 99 channel portables; A model for 8 channel) have partial cloning.)
4. Simultaneously depress the PTT and Monitor button on radio A and hold.
5. Turn on radio A. The green LED turns off. Release the PTT and the Monitor button on radio A (HT600's and older MT1000's (A model for 16 and 99 channel portables) beep when cloning is complete). Turn radios "off and on" to reset.
6. Cloning is complete once the green LED turns off. Release both the PTT and Monitor button on radio A. Turn radio A off and on to reset.

NOTE:
For MDC front covers (NTN5456, NTN5457, NTN5458, NTN5459, and NTN6009B), make sure that radio B is turned on before it is connected to the cloning cable.

NOTE:
All VHF wideband radios (146-174MHz) are "C" model radios. A "C" model radio can be cloned only to/from another "C" model radio. An attempt to clone a "C" model radio to an "A" or "B" model radio will result in an unsuccessful cloning attempt.
Any unsuccessful cloning attempt (depending on operating condition of the radio) will result in one of the following alerts:
1. in receive (rotary radio) - 1600Hz continuous alert tone
2. in receive (display radios) - 88 displayed on LCD
3. in transmit - 1600Hz beeping alert tone

Two things which come to mind, one would be if the PTT on the remote mic is bad/defective, second would be you are plugging the audio device in with the radio turned on.

If your remote mic is failing, the PTT is a repairable item, as is the cord on most models.

I have never seen this problem before, check if the VOX is activated, this could cause to transmit the radio, but the voice must be transmited. check if the Accesory connector is not dirty, clogged or damaged