Am I turning in to magneto?

[taximan]

Hiya,

This has me really puzzled but I am sure it is only a silly problem somewhere.

MBFM boots up fine,shows 'launching cs'

All functions work okay ...............but if I place my hand above the cs (not actually touching it) the display will flicker and sometimes change to different functions.

Button 'select six' reacts consistently to putting my finger near it (not actually touching) if the lcd is in 'start mode' displaying 'ens/i/ptch/name/chn/audio' and I go near button 6 the screen changes to 'step/mode/#1/#2/#3/rate (flashing)/sync/cc#1'

If I put my finger near it again (regardless of what is displaying) it will affect it.

Gets better ......I press escape and go back to what I call the start screen (as detailed above).

Then I place my hand above the cs above where the din board and led matrix are located in the case (again not actually touching anything) the display will change to inst/play/con/fdbk/prng/fine/port/susk...etc etc.

now when I put my hand near it (the cs) the lcd functions select 1 through to select 5 flicker like crazy.

I dont know if it's a dodgy capacitor or bad joint somewhere but I have rebuilt this thing three times now,so I am pretty sure the problem does not lie with the core or opl3 board.

Its as though something is discharging through the casing,really weird stuff.

EDIT If I disconnect the din and dout boards placing my hands near the button six causes no problems (no power going through obviously) so it suggests the problem is with the din side of things.(I tried it with just din board connected and the same problem manifests) END EDIT

There is a funny side to it though, I have told the kids it is a telepathic machine I have invented with thought controlled display and they are like ''wow dad''....he he he.

Any help,wild guesses or sympathetic piss taking is welcome.

cheers

Paul

Edited April 30, 2010 by taximan

[Flemming]

Even though TUI (Telepathic User Interface) is pretty cool i hope you get the booboo fixed :)

Whenever i experienced a similar problem (proximity aware controls) it usually was caused by poor ground connection from the knob/switch in question. When my finger got too close it would work as a ground connection....

But i highly suspect your situation to be of another nature - mostly because it seems that my issues always tend to be isolated incidents caused by a healthy mix of eagerness and plain stoopidity :tongue:

[taximan]

Hiya Flemming,

I have started stripping it down (again lol) disconnected ins/op select buttons 1 to 4,the ins/op select button and all of j5 and j6 on the din board......still erratic behavior from lcd....... disassemble..... disassemble....disassemble.

cheers

Paul

[TK.]

Sounds like you haven't mounted all parts of a DIN module - especially the 10k pull-up on each 74HC165 SER input is important to ensure that no unindented button function will be triggered.

If all parts are mounted: check the soldering joints around these resistors.

Best Regards, Thorsten.

[taximan]

Sounds like you haven't mounted all parts of a DIN module - especially the 10k pull-up on each 74HC165 SER input is important to ensure that no unindented button function will be triggered.

If all parts are mounted: check the soldering joints around these resistors.

Best Regards, Thorsten.

Hiya TK,

I mounted everything as in the schematic (it all came as a kit anyhow,so I just kept soldering until I ran out of bits).

I wasn't too keen on the 'tightness' of the tracks on the dinx4 board so I have attacked it with the dremmel leaving plenty of room around any possible shorts (while still leaving the tracks that need to be there,obviously) and it seems your advice is bang on the button,one of the resistors had pushed the track away from the underside of the board making the contact intermittent,I will be re connecting it all back up some time this week and hopefully the problem will be sorted.

Thanks for your input.

cheers

Paul

[stuartm]

I've had a similar problem with my MBSeqV3.

When I reached for the left part of the Box, the Seq would always switch to the "Edit" screen, before I could even touch a button. Very strange.

I can't remember what finally fixed it, but it could have been the R+C Terminator on the end of the DIN and DOUT chains.

At least that made my LEDs stop flickering all the time.

[taximan]

Hi all,

Problem fixed,it seems that the 'loose' resistor was the source of the problem as the din board is working as intended now and the lcd display is fine......ta daaaaa!

Right....now to start on the dout side of things.......where the heck did I put those leds?

Oh yes, another thing that just sprung to mind is this,I made a bank-stick with 8 ic sockets and perf board but only had four chips to put in it but the memory would not hold any patches or format,so being the clumsy sod that I am I thought it was something to do with my lack of finesse and rebuilt the 'memory module'....no success.

I decided to try the chips from my sid project and they worked with no problem at all,the only difference in the parts is as follows..........yes I know I know,I sorta thought to myself after rebuilding it why didn't I just test it with the meter.......funny things brains are....anyhow...

24LC512/ip uwb/0930 would not work at all,as though the core didn't recognize them.

24LC512/ip c8m/0949 worked straight away with no problems at all.

Voltage at measured at pins @ 5.05 volts,so it's not a low voltage issue as I read someone else had.

Mods if you want to move this post so that the bank-stick issue may help someone with problems please feel free.

Cheers

Paul

Edited May 6, 2010 by taximan