Hello,
servicing the SDS9 can be a horrible thing. I "repaired" several units by simply changing the software 6.0 or 5.0 back to 3.0. The explanation of this MAY be, that when the s/h capacitors age, they can't react to the "fast" scanning of software as 5.0 or higher. Or anybody has another idea why? Doesn't matter, the result counts :-)
Stories like this I can tell a lot. I hate to check SDS9's. People complain about parameters not being able to adjust or one trigger missing. In ALL cases one or some of the demuxer ICs (4051) are dead. They don't deliver the right data or trigger to the sound producing units. I always replace all at once, for me as a slightly experienced service person, this takes A DAY. It is very little space on the SDS9s PCB, meaning, that you can destroy a lot if you don't pay attention.
If someone is buing these old devices, he has to remember, that the components are aging, not only the capacitors. And if you fixed one thing today, tomorrow another thing might break. These old beasts are not reliable and I would never recommend to take them to stage. So frustration helps nobody, think of an old car like an MG. You spend much more time mending something than driving, and this is ok.
There are many people out there "shooting" an SDS9 at EBAY and later complaining, that nobody knows how to repair it. I know how to do it (this costs money) and I supply anybody with Thierry EPPHERREs worldwide best schematics (this is free).
SDS9: It is not plug and PLAY, it's plug and PRAY.
Good luck
Michael
----- Original Message -----
From: Brian Horton
To: Simmons_Drums@yahoogroups.com
Sent: Friday, July 20, 2012 7:23 AM
Subject: [Simmons Drums] Re: SDS 9 elementary problem & deeper fault
in my learning of electronics if all other toms are workingfine i doubt it is the transformer,if capasiters blow they will become convex instead of being flat.diodes can be tested using a metre,special setting see manual on metre ics look up number on top of ic and see inputs and out puts for voltage.the other toms should pretty much be the same as the high tom so compare voltages from medium tom to high..if any thing the first place i would look at is the pots,volume and sensitivity as they get dusty ect ,create unwanted sounds when adjusting
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