Cheetah MS6 Problem

snod_donkey · Post by **snod_donkey** » Tue Nov 01, 2011 11:50 am

I have been given a Cheetah MS6 synth module but sadly it's faulty

On power up all i get is a flashing display showing F E FF and thats as far as it goes. Does not respond to any buttons on the front

Anyone have any ideas before i burn it?

schmidtc · Post by **schmidtc** » Tue Nov 01, 2011 5:59 pm

Burn it?

snod_donkey · Post by **snod_donkey** » Tue Nov 01, 2011 8:38 pm

schmidtc wrote:Burn it?

Thanks for the help on that... do you think there will be any chance that would fix it? I do have a very large axe so might be better to give that a go first..

cryabetes · Post by **cryabetes** » Tue Nov 01, 2011 9:00 pm

you try replacing/upgrading the EEPROM?

found this through a brief google search:
http://www.maad.net/ms6/
Failing that, you could at least talk to the guy that runs the page, he's probably come across something similar.

cheetahms6love · Post by **cheetahms6love** » Sun Jul 16, 2017 9:15 pm

Hello, I'm having same error on my cheetah MS6 display FEFF?

Any resolutions?

Many thanks
Elliot

Rasputin · Post by **Rasputin** » Mon Jul 17, 2017 6:01 pm

cheetahms6love wrote:Hello, I'm having same error on my cheetah MS6 display FEFF?

Any resolutions?

Seeing as the OP didn't have the courtesy to come back and report what was (not) tried and what the results were, you're mostly on your own here.

I don't have a Cheetah, but I'm thinking there are two or three likely culprits to look at. The biggest thing is to check the power, specifically that the 5VDC is within spec and that ground is actually grounded. Giving the PSU a good thrice over is a smart thing to do with pretty much anything vintage, broken or not.

Second is the battery. The original is a Ni-Cad that you should swap out if it hasn't already been done. If the battery has already been swapped out for something newer then check that it's still good. A bad battery could lead to faulty RAM values which could cause such an error. If the battery has been replaced for one in a holder then try taking the battery out and leaving it out for a bit then putting it back in. The other approach would be to short the RAM backup to ground in order to clear it. You'd have to find the correct pins/points by looking at the schematics (of which I have two versions, if you need them).

Third is the EPROM firmware. Could be faulty at this point in its life, but unfortunately I don't have a version of the stock ROM to give you as a replacement or to even tell you what the checksum is supposed to be, so the best option is to buy the upgrade EPROM.

Maybe someone here owns the old EPROM and can rip it or at least generate the checksum so you can compare your EPROM value to what it is supposed to be.

HyprDrivr · Post by **HyprDrivr** » Thu Aug 10, 2017 3:07 pm

Hi all!

I have a MS6 and hade the same problem.

It seems that the FEFF error is just the machine telling you its starting in calibration mode for some reason, probably losing battery power, janking out the OS EPROM or the like.
Just leave it powered on and it will start to go thru all the voices and it will probably work as expected.

Hope this helps.

paugui · Post by **paugui** » Wed Oct 04, 2023 1:46 am

This is an old post by now, but did anyone found out how to fix the FE-FF at the start?

One of mine is having this issue too, but as mentioned above, it seems it just needs to calibrate, and then it works just fine...

I am tempted to believe it might be a battery issue, despite I had it working, powered it off for less than a minute (without unplugging the power cable), and that issue still showed up...

Since it takes some minutes for it to start working properly, would be great to just fix it...

By the way, if it still has the original firmware, there is no way to dump the patches in memory, right?
And if I change the battery, will it still keep the original patches available?

Cheetah MS6 Problem

Re: Cheetah MS6 Problem

Re: Cheetah MS6 Problem

Re: Cheetah MS6 Problem

Re: Cheetah MS6 Problem

Re: Cheetah MS6 Problem

Re: Cheetah MS6 Problem

Re: Cheetah MS6 Problem