GT/22 power problem

Chuk

Chuk

Active Member
Hi all.
My GT/22 failed last night at rehearsal. It booted up just fine and worked normally but after a minute the power went down.
I checked the power input from the AC adapter and it was not a good connection. If I wiggle the adapter jack the power goes on and off. It certainly appears that the jack is damaged BUT the unit refused to boot even though there was power getting through. In fact I think the OS is scrambled. I get a "NO PRESET" message in the display and some of the button displays light up with scrambled goobledegook. I've tried holding down the two manual reset buttons under the main display but nothing happens. I've also tried connecting via my RJM phantom power adapter box but it's the same result. I haven't sourced a replacement adapter as yet but I'm hoping that it comes good because playing without it proved a nightmare.
 

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UPDATE:
I have removed the plug and tested the adapter with a multi-tester and it is outputing a little over 12vDC. I found a better plug and soldered that on the end while observing of correct polarity. However the result is the same (see pics above). I'm tempted to attempt to reload the firmware but I've held off until I hear from one of you RJM gurus or from Ron himself. :(
 
Last edited:
rjmmusic said:
I'm not sure why the power cut out, but it seems to have scrambled the flash memory. You'll need to go through this process to recover:

https://rjmmusic.freshdesk.com/solution/articles/215581-how-to-do-a-complete-wipe-of-settings
Click to expand...

Ron, I followed your instructions and re-loaded flash memory, firmware and then my settings.
It seems to be working fine again. Thank you for your prompt assistance.
It's a sweet, sweet thing to see those lovely coloured panels again.
Cheers.
 
Hi again Ron.
The same thing has happened again with that power supply (which I had repaired).
BTW: the GT22 has been working perfectly since the last correspondence.

Once again I powered up the GT22 and the power supply , through a bad contact, was intermittent for a few seconds and the whole GT22 locked up.
I immediately replaced the power supply with a new one.
I then followed your instructions (as above) but this time I can't get the GT22 to recognize the flash drive when booting up with the two black buttons depressed.
The first pic shows the GT22 upon booting up whether I depress the two buttons or not. Inserting the flash drive makes no difference.
After about 10 secs the two lower rows of buttons light up as in second pic. It's always the same regardless of two buttons or flash drive.
?
 

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Ok, this time the power cut has done something to the memory in the top two rows. I've seen this happen and for some reason, the more recent firmware releases aren't able to recover from it. All I know is that downgrading to an earlier version, then upgrading again has fixed it in all prior cases. I've attached a firmware file that should help.
 

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Tx for quick reply Ron.
I removed the flash memory file from the flash drive and loaded up MMGT234.rif and repeated the process.
Nothing changes. Its the same thing every time. Pressing the two buttons does nothing.
The two small screens read "MMGTB Boot v1.0 Awaiting download".
 
That's unfortunate, then... we're probably looking at a repair. There's one other thing to try. Not sure it'll help, but it's worth a try. Make sure 2.3.4 is installed. Open up the GT and disconnect the gray ribbon cable from the top circuit board. It's ok to leave it connected to the other boards. Then, power up the GT. See if the top row recovers. It will show the bootloader screen, but will hopefully go through a firmware update of the top row shortly after. The other boards won't turn on. If that does help, reconnect the cable to the first board, but disconnect it from the lower 2 rows. Power up again and see if it recovers the second row.
 
I have 4.2.3 loaded but how can I reload 2.3.4 ? Can I use MMGT Editor?
Is there any point in trying your 'ribbon cable fix' with the 4.2.3 firmware loaded?

FWIW: (I have setup my normal midi cables for bi-directional communication with my AxeFxIII.)
The bottom row is lit but non functional.
The second row, except BANK DOWN (far left), is lit and actually functional. These IAs turn blocks on/off in the AxeFxIII and they update when I change presets from the AxeFxIII front panel. The main GT22 window also updates when I change presets from the AxeFxIII front panel.
I do have the GT22 in communication with MMGT Editor and managed to download the onboard data including Presets, Song Names and Set Lists.
 
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