Okay, as long as you haven't done anything to any of the DMS' you have, this sounds like it could be a very simple fix!
So, using your Kenwood Keg and any of the original DMS' - here's what you need to do:
1. Download and install the DMS Tools: http://forum.phathack.com/index.php/topic,2605.0.html
2. Insert the DMS cartridge into the cradle
3. Start the DMS tools.
If you are using Windows XP, then you need to use the 'All Programs\PhatHack\PhatHack DMS tools' shortcut.
If you are using Windows Vista or Windows 7, then you need to use the 'All Programs\PhatHack\PhatHack DMS Tools (Elevated Rights)' shortcut.
4. Switch the DMS tools to 'DMS Tools' mode, by clicking on the 'DMS Tools' button on the bar at the top of the program.
5. If not already selected, select the DMS from the 'Select the destination device' drop down.
If you started the DMS tools before inserting the DMS into the cradle, hit the refresh button to get it detected.
6. Your current firmware should be displayed next to 'Current firmware:' You should find this also selected in the 'Select DMS firmware' dropdown.
We need this to reflect the head unit you are using, which if I understand correctly is a Kenwood one..it's always worth updating to the latest version so if not already, make sure the dropdown has Kenwood v13.01 selected
7. Ensure the option 'Install Non-hacked firmware' is checked.
Unless you know if the box has been hacked already, in which case you can leave this option unchecked.
8. Ensure the option 'Reflash box with firmware' is checked.
Because we don't know the current state of the box, or if one of the DMS' has inadvertently updated your Keg to act as a different variant than a Kenwood Keg, then this is the safest option.
It will mean however that you will need to give the box plenty of time to perform the firmware update and this can take upwards of 7 to 15 minutes in total to complete!
9. Click on the 'Update firmware' button. The software will now prepare the DMS and the firmware.
10. Start PhatNoise Media Manager, PhatNoise Music Manager or your choice of DMS management software.
Load a single playlist onto the DMS, just so that we can prove everything is working.
10. Correctly eject the DMS from the PC.
If your chosen software supports it, then use the appropriate Save/Eject process.
Otherwise, close your software and you'll find an icon in the bottom right next to the system clock where you can eject USB devices. Make sure you eject the PhatNoise device and this should make sure the DMS is safe for use in the car.
Note to self: Add an option for this in the DMS tools!
11. Take the DMS to the car, but don't do anything yet!
12. Unplug the cable from the Keg, and reset the Kenwood head unit.
There's a small reset button on most, if not all, Kenwood head units.
Attaching multiple boxes to the head unit often gets it confused and they'll not correctly see the box until you do this.
Before pressing the reset button, if the unit has a stereo code make sure you know it as you will be prompted for it once the device is reset!
13. Plug the cable back into the Keg, insert the DMS into the Keg... switch the head unit to select the Keg and wait! Patiently! Very patiently!
You'll notice the green light on the Keg flashing fairly rapidly whilst this process is happening.
If you notice that the sequence appears to be: red light on, flashing green lights flash for a while, red light goes out, and this repeats - there's a problem and the update is not occuring.
14. Once the update is complete (don't forget, be patient!) the box should reboot itself.
Make sure you switch your head unit to reselect the Keg.
And all being well, your playlist should start playing... and everything is back to normal!
If not, then don't worry - we have ways of identifying what could be wrong!