Clean old oxidated pcbs

[ma9]

Hi my post is a bit off topic perhaps..

A friend of mine gave me an old Alesis Mmt8 for free, because it didn't work anymore. I've read on the net that this sequencer often has problem with buttons, because it uses gummy conductive pads that touch metal pcb's tracks, like often happens in calculators.

I cleaned the pcb tracks with alcohol, now they are shiny and now at least they work! But they still don't make good contacts and I have to press a lot to activate them...

Can you suggest me a good way to clean the conductive tracks better?

Bye!

[smashtv]

The Chemtronics "CircuitWorks Rubber Keypad Repair Kit" is what you need, anything else and you will be doing it again......

(at the vending company I performed several hundred repairs on NSM jukebox remotes that had been dunked in water/beer, stepped on, melted, thrown or otherwise abused.....This kit would always bring back the dead keys....)

If you have trouble finding Chemtronics stuff locally (wherever you are) let me know.

best

Smash

[MMorph]

Well, after cleaning the contacts with pure alcohol there probably is no much you can do unless the contact pads are heavily oxided. The problem most likely lies on the buttons. Besides that these can get as dirty as the contact pads on PCB, they tend to wear out as well. Using solvents on cleaning them isn't recommended though.

Edit: Ah, Smash got it first. I thought there was some sort of contact restorer available around but couldn't figure it out.

[AndrewMartens]

That reminds me, I need to go and fix up the contacts on my MMT-8 and HR-16... picked up the pair for $20 a few months ago, and the only thing that needs doing is making the contacts reliable again...  Thanks for the tip, Smash!

[jdutcher]

my MMT-8 and HR-16... picked up the pair for $20 a few months ago

where?

[arumblack]

And this should do the trick for my Sequential circuits six track too.... I hope so antway. can change patches, sometimes........ some number keys don't work. I tried alchahol too and it seemed to help for a short while.

Good off topic post ma9!

[ma9]

thanks! Now I have to find a dealer :D I'll send an email to ask for it

[moebius]

Hmm..

Does anyone owning the MMT-8 also happen to have a digital camera and some good will?

The short version of the story is: I've got a MMT-8 mainboard and I'd like to make a working sequencer out of it :D

(the long version-- I had one, a complete unit, which just started to fail too often. Tried my version of "the MMT8 Button repairs; concrete fix", which can be found from http://www.mmt8.com/misc.html (not that I had ever heard of it before ;)) and never finished. The day, when my mom told that "She's tired of her cellar having "just too much unorganized junk of yours"", was probably the day when I made this mistake of throwing out (too) much of the unnecessary junk, also the panelboard of the MMT-8..)

So, could someone take some high resolution pics from the both sides of the panelboard? Inside pics of the MMT-8, so I can see how the cables are connected (not that it wouldn't be easy to figure out)  Also a pic of the mainboard.. I've taken out the connector of the LCD, but also something below the battery?! And what does the LCD say-- It's a standard HD44780 based one (with a backlight?), right?

So, if I could trace the schematcs of the panelboard, I'd like to make a board for a rack mounted unit..

Bye, Moebius

p.s. Eh, a misc request-- I have the 1.07 version of the firmwave (with a evil memory dumping bug), does anyone have the latest version, 1.11?

[AndrewMartens]

@jdutcher

Got them used at a consignment store ... clearly someone had gotten fed up with the flaky buttons and couldn't be bothered to fix them.  I picked them up, read about the problem, checked to make sure that they worked (other than the button issues), etc.  One of the LCDs is compromised (a little dim due to an internal leak in the display), but it doesn't appear to be getting worse and I can just ignore the problem.

@moebius

I'm hopefully getting a digital camera one of these days, I'll try to remember to snap some pics of the MMT-8 panelboard, LCD, etc..  I wouldn't mind finding the 1.11 firmware as well, since mine is also a 1.07 unit.