[sdiy] problematic sh101

[mark verbos]

Ruud,

I did the very same song and dance with an MC-202 for about 10 years on 
and off until I finally fixed it for real a couple months ago. I would 
bet you it's a hairline crack in a solder joint ont he board somewhere. 
After soldering all the connectors and chips as well as probing between 
the processor and other places I found that there was a crack in the 
solder on one pin of the processor. When I put the meter probe onto it, 
it would reconnect, so I never noticed it when I was measuring. All it 
took was touching the iron to the pin for a second and now everything 
works as new again. F__king wave soldering!!!!! I guess when you make 
20,000 of a product you have to make them fast. ;)

Mark



Rude 66 wrote:

>hi everyone,
>
>i'm trying to troubleshoot an sh101 for a friend (yes senso, that one again!
>;-) first i thought it was the sequencer board, since when you push on the
>case there, all the lights for the sequencer, arpeggiator etc go on and off
>at random. however, i disconnected this board and now i find that also when
>the synth is powered up and the case is stretched or pressure is on it in
>any way, it completely loses its power. bend or push around a little and it
>comes on again.. when working, the synth is fully functional.
>inside, i noticed the bottom board being a bit warped. i cleaned it up, and
>resoldered some connections that were a bit shady.
>
>my big question is: is all this more likely to be caused by the
>wiring/connectors, or by bad solder joints? before i start on resoldering
>all connections, i'd like to ask some advice on that.. the wiring looks
>solid, and i've taken most of the connectors off and cleaned the contacts.
>i've also cleaned and bent the little metal contact points on top of some
>boards that appear to make a gnd connection with the metal back plate.
>
>problem is that the plastic case makes it very 'flexible' in that if i play
>around with anything, the whole case flexes and it's very difficult to
>pinpoint the problem to one area..
>
>any tips? (apart from 'give the thing back, it's a waste of time') ;-)
>
>thanks!
>
>ruud
>
>
>
>  
>