• To anyone looking to acquire commercial radio programming software:

    Please do not make requests for copies of radio programming software which is sold (or was sold) by the manufacturer for any monetary value. All requests will be deleted and a forum infraction issued. Making a request such as this is attempting to engage in software piracy and this forum cannot be involved or associated with this activity. The same goes for any private transaction via Private Message. Even if you attempt to engage in this activity in PM's we will still enforce the forum rules. Your PM's are not private and the administration has the right to read them if there's a hint to criminal activity.

    If you are having trouble legally obtaining software please state so. We do not want any hurt feelings when your vague post is mistaken for a free request. It is YOUR responsibility to properly word your request.

    To obtain Motorola software see the Sticky in the Motorola forum.

    The various other vendors often permit their dealers to sell the software online (i.e., Kenwood). Please use Google or some other search engine to find a dealer that sells the software. Typically each series or individual radio requires its own software package. Often the Kenwood software is less than $100 so don't be a cheapskate; just purchase it.

    For M/A Com/Harris/GE, etc: there are two software packages that program all current and past radios. One package is for conventional programming and the other for trunked programming. The trunked package is in upwards of $2,500. The conventional package is more reasonable though is still several hundred dollars. The benefit is you do not need multiple versions for each radio (unlike Motorola).

    This is a large and very visible forum. We cannot jeopardize the ability to provide the RadioReference services by allowing this activity to occur. Please respect this.

Harris XG-75M "Warning! Lost MRU"

Trooper78

Member
Premium Subscriber
Joined
Jan 31, 2010
Messages
39
Location
TN
Hello, I have a Harris XG-75M, which has been working great with no problems for months now. Saturday morning turned it on, and got the " Warning! Lost MRU " on the control head. I tried a different control head, same thing. I can read the radio, but it fusses when I try to write to it. Not sure of what is going on. Any suggestions ? Thanks
 

Mattsenft

Member
Premium Subscriber
Joined
Jan 22, 2006
Messages
181
Location
Harrisburg, PA
If it is a remote mount radio, try a different CAN cable. Make sure you have a CAN terminator on at least one CAN port with a remote or dash mount radio. Also if it doesn't have the latest control head firmware you could try to update that, as Harris has resolved a few issues with the CAN bus in the past CH-721 firmware release.
 

Trooper78

Member
Premium Subscriber
Joined
Jan 31, 2010
Messages
39
Location
TN
It is a remote mount, but the cable is brand new. And it was terminated. How do I go about updating the firmware. I bought the radio on ebay. It was working just fine, then it decided not to.
 

ElroyJetson

Getting tired of all the stupidity.
Joined
Sep 8, 2002
Messages
3,883
Location
Somewhere between the Scylla and Charybdis
What was the feature package in it? Just asking because I've got like 50 of them with P25 Phase 1 trunking and you could probably get one from me so cheaply that you might prefer to do that rather than try to recover yours.
 

Trooper78

Member
Premium Subscriber
Joined
Jan 31, 2010
Messages
39
Location
TN
What was the feature package in it? Just asking because I've got like 50 of them with P25 Phase 1 trunking and you could probably get one from me so cheaply that you might prefer to do that rather than try to recover yours.
It had phase 1 and 2....if I could recover it, that would be great.
 

rescue161

KE4FHH
Database Admin
Joined
Jun 5, 2002
Messages
3,675
Location
Hubert, NC
Lost MRU means that the Main Radio Unit is not talking to the control head. Check the power on the main radio. Typically, the control head will have power to display the message, so I'd check the fuse on the main unit.
 

Trooper78

Member
Premium Subscriber
Joined
Jan 31, 2010
Messages
39
Location
TN
Yeah, I checked both fuses. They are both good. Connections are all good, the CAN cable is new. Voltage to head and radio are good.
 

rescue161

KE4FHH
Database Admin
Joined
Jun 5, 2002
Messages
3,675
Location
Hubert, NC
Is the CAN terminator still in place? If it is missing or bad, that will cause the same problem.
 

Trooper78

Member
Premium Subscriber
Joined
Jan 31, 2010
Messages
39
Location
TN
Yeah, I think I tried a different one, but, unsure at the moment. I am actually at the NICU, currently. My son was born on the 4th, and he has breathing problems. As soon as I can, I will recheck that.
 

Trooper78

Member
Premium Subscriber
Joined
Jan 31, 2010
Messages
39
Location
TN
OK, so I tried a bunch of different terminators, no luck. I converted it to a dash mount, and it still shows Lost MRU on the screen. It also keeps booting, over and over. Any help to recover it, would be greatly appreciated.
 

prcguy

Member
Premium Subscriber
Joined
Jun 30, 2006
Messages
16,439
Location
So Cal - Richardson, TX - Tewksbury, MA
OK, so I tried a bunch of different terminators, no luck. I converted it to a dash mount, and it still shows Lost MRU on the screen. It also keeps booting, over and over. Any help to recover it, would be greatly appreciated.
Did you diddle the bits on the control head with a terminal emulator and make it a dash mount? If so and if it still doesn't work its probably a broken radio.
 

towersites

Member
Premium Subscriber
Joined
Apr 16, 2009
Messages
90
Location
Denver, CO
OK, so I tried a bunch of different terminators, no luck. I converted it to a dash mount, and it still shows Lost MRU on the screen. It also keeps booting, over and over. Any help to recover it, would be greatly appreciated.
It has been programmed with an uncappable version of flash code. I made that mistake once.
 

towersites

Member
Premium Subscriber
Joined
Apr 16, 2009
Messages
90
Location
Denver, CO
The XG75 radios are more sensitive and less forgiving than older M7300 radios. The version of RPM has to Match the Firmware range.
I was able to recover by programming a later version of firmware.
 

Trooper78

Member
Premium Subscriber
Joined
Jan 31, 2010
Messages
39
Location
TN
I have RPM 14C05. Would you have a copy of the latest firmware, that you would be willing to share. I would greatly appreciate it.
The XG75 radios are more sensitive and less forgiving than older M7300 radios. The version of RPM has to Match the Firmware range.
I was able to recover by programming a later version of firmware.
 

Radio_Lab_MIA

Member
Joined
May 9, 2023
Messages
6
Four fuses by the connectors on the PK board tend to blow when the DB44 DB9 is removed hot. They are tiny surface mounts, three one-amp fuses, and one three-amp fuse. I repair these all the time on the XG75. The three-amp fuse is behind the cables. Check these first for lost MRU. I can guide you in troubleshooting if that is not the issue.
 

Attachments

  • Fuses xg75.PNG
    Fuses xg75.PNG
    1 MB · Views: 31
Last edited:
Top