[sdiy] tr909 schematics -> sequencer part

[Rude 66]

well, resoldering the circuit board didn't do much here. the problem seems
to be related to the patterns. all bank/pattern select functions work, sync,
tempo etc work, but as soon as you play a pattern, it's impossible to
program it: lights come on/off randomly, and the patterns are one big mess.
also steps you turn on or off are something else in the next run through,
and a lot of sounds seem to be double triggered (or it's stuck in flam
mode). other weird thing: is start/stops in pattern mode, but not in song
mode..

after some consultation with Senso, tonignt i'll fire it up with bare boards
and power on to see if there's any spots where i can detect trouble.
suspicious spot is the bottom right pasrt of the seq board, because there a
little clip was also knocked off the plastic side panel of the case. it
seems to have taken a beating.

what's the best way to measure and fix a broken trace on something like
this?? i have a dmm, but no scope..

thanks!

ruud


> Strange, I fixed a 909 for a friend last night!
> It also had sequencer-troubles, it turned out to be a broken trace from
> the CPU to the ROM. This was propably caused by the roland-tech that
> changed the processor, RAM and ROM a few years back.
> This particular 909 had an EPROM installed in a socket instead of the
> usual solderd in ROM , so I made a hex-dump if anyone need the 909
> program.
>
> I was fortunate enough to find the fault without the schematic but if
> anyone scans it I could use a copy for next time!
>
> regards
>
> /Daniel
>
> >>> "Rude 66" <rude66 at xs4all.nl> 2005-03-11 22:04:00 >>>
> does anyone have or know the online location of the tr909 schematics? i
> just
> found out mine didn't survive the last gig we did..
> all the sounds are there, but the sequencer is mad! some buttons don't
> work,
> etc. it's behaving like there;s a loose contact somewhere in the
> sequencer
> section
>
> i need to know only the sequencer part.. the voices all seem to be ok.
> but
> all i can find online are parts of the schematics for the different
> voices..
>
> my thanks forever! ;-)
>
> ruud
>
>