Vintage Simmons Drums (UK) Users Group

I replaced my battery in my sds 9 ,mtm,and mtx the same way i described in the sds 9 descriptions as before no resistors or any thing to be taken out,three 1.2 volt AA batteries equals 3.6 volts which it calls for.they where ni cads as i recall rechargeable from radio shack,and the four AA holder in plastic ,just bypass the fourth battery spot with solder jumper cables ,case is in plstic in case of leakage and used d0uble sided sticky tape to mount to sie walls,and of course positive wire to positive on bord and negative to negative on board .as stated in service guide batteries have to be charged for mtm to work,my mtm  and all worked fine this way,just heard mine might not be trggering due to capacitors failing after all those years.sure would be nice to have readable schematics



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From: jesper <jesper@...>
To: Simmons_Drums@yahoogroups.com 
Sent: Wednesday, December 28, 2011 1:57 AM
Subject: [Simmons Drums] MTM and change of battery


  
Hi list,

I thought I should change the battery of my latest MTM today. But since 
I was stupid enough not to make notes or take pictures when last time 
doing this I dug out one of the other units to have a look.

No. 114 had it's battery changed by the former owner and as far as I 
remember I copied the work in my other MTM. Apart from the removal of 
the old battery and the insertion of a AA-sized Lithium dito I can only 
see one change: the lifting/removal of resistor 37. I did the same on my 
other MTM and both works well, both functions and memory.

Here's a shot of what can be seen inside no. 114.
http://www.electronic-obsession.se/studio/simmons/mtm_battery_mod.jpg

So techs, let me know if this is wrong. Should I lift diode 30 too? 
Anything else? The schematics aren't the best and I'm no master at 
reading it anyway. :)

Happy holidays,
-- 
electronically yours, jesper

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www.electronic-obsession.se



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