Jmp-1 wont factory reset, midi wont change, cant store patches

[Pattrahan13]

Hi guys. Newbie here with a jmp-1 i just purchased.

The data knob works for changing patches, tone control values but here what doesnt work.

- i cant do a factory reset (od1+cln1+poweron) : nothing changes
- the data knob doesnt change the midi channel - stays at 7
- when trying to save a patch, after pressing store, the data knob doesn’t change the pactch.. imjust reads “L”

what’s the problem? Any one ever experienced this?

 

[Pattrahan13]

Dont ask.... it all started to work after 25 mins pf trying stuff

 

[FracStrat]

Buy a can of DeOxIt G100 …… If it acts up again …Spray a bit into the pots and hit the contacts on the jacks …… Magic Stuff !!

 

[Pattrahan13]

Probably dirty contacts under button but yes, I’ll use some cleaner

 

[crossroadsnyc]

I've always kinda wanted one of those.

 

[FracStrat]

I've always kinda wanted one of those.

They’re Awesome !!

JMP-1 and 9200 5881

• FracStrat
• Jan 28, 2020

 

[crossroadsnyc]

They’re Awesome !!

JMP-1 and 9200 5881

• FracStrat
• Jan 28, 2020

Oh, I'm sure! It's always intrigued me!

On a side note, I've also wondered why they never tried releasing them again as a reissue ... I mean, w/the technology available today, couldn't they likely improve upon it? Maybe the overall interest w/guitarists just isn't there anymore? Would be a hell of a lot more appealing to me than another lower watt version of something already out on the market.

 

[FracStrat]

Oh, I'm sure! It's always intrigued me!

On a side note, I've also wondered why they never tried releasing them again as a reissue ... I mean, w/the technology available today, couldn't they likely improve upon it? Maybe the overall interest w/guitarists just isn't there anymore? Would be a hell of a lot more appealing to me than another lower watt version of something already out on the market.

That’s a great idea ……
I think the resurgence of 19” rack stuff may be on the horizon ……
There are so many Pedal builders out there …… Ridiculously Powerful Midi Stuff is everywhere ……
Marshall does Marshall better than anyone ……
It’s more than the sound and tone ……It’s also the Look , Reputation and Mystique ……
I hope the future holds Good Quality yet innovative Amps we Want to Own ……
I hope the Brand does not get relegated to Coasters and Door Mats ……
Here Here !!

 

[johan.b]

You probably already know and done just that but, just because... you need to hold in od1+cl1 (as you stated) several seconds efter applying power. If you let go too soon, it just boots to latest patch

 

[Dogs of Doom]

also, you need to unlock it...

revisit this post:

Old thread I know but I just gone through these issues and here is the answer I wish I would have found here!

Looking at the video, I got these exact problems after changing the battery. Look like the preset memory got corrupted by lack of sufficient power.

Values jumping around when pressing buttons, data would stay stuck or respond slowly, preset loading was buggy. High pitched noise when messing around for a bit, etc.

You need to reset the unit (Hold OD1+Clean1 then power the unit) but (the important part) the unit need to be UNLOCKED first.

You can tell yours is locked when you hit Save: the display show "St L" That mean the save function is disabled so you can't write on the memory.

To unlock, press Save and while you see "St L" press the "Channel" button. The unit will unlock and display the current channel to save to ex: "St 01".

Now perform the reset function OD1+Clean1+Powerup and the memory will refresh itself and all glitch, lag and weird sounds will be gone.

Hope it help someone!

 

[SlapHand]

Dead battery?

 

[anitoli]

Be careful poking around in those, that MIDI section is static sensitive and there are no replacements for that EPROM that i am aware of.