Roland sh-101 LFO/CLK RATE problem

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harrymusic1995
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Roland sh-101 LFO/CLK RATE problem

Post by harrymusic1995 » Thu Apr 30, 2015 7:27 pm

hello, new to the forum here and after some advice please,

my roland sh101 has an issue with its lfo/clk rate, even with the slider for speed all the way down the rate of lfo/clk is still REALLY fast and the red light is almost a solid colour its that fast, then when its on full its unbelievably fast, it never used to be this way and i was wondering if there is a way to solve the fast issue "under the hood"

any ideas guys and gals??

thanks :) :?: :?: :newhere:

Harry[/font][/font]

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synthparts
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Re: Roland sh-101 LFO/CLK RATE problem

Post by synthparts » Fri May 01, 2015 7:31 am

Most likely a bad slide pot.
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Jonathan40
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Re: Roland sh-101 LFO/CLK RATE problem

Post by Jonathan40 » Mon Jan 11, 2016 2:13 am

I'm having the exact same problem with my SH-101, and haven't found any LFO/CLK adjustment on the schematic or circuit board. May I ask if the issue was ever resolved?

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garranimal
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Re: Roland sh-101 LFO/CLK RATE problem

Post by garranimal » Mon Jan 11, 2016 2:32 am

Might try cleaning the slider with some contact cleaner.

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Re: Roland sh-101 LFO/CLK RATE problem

Post by Jonathan40 » Fri Feb 19, 2016 4:16 am

garranimal wrote:Might try cleaning the slider with some contact cleaner.
I tried cleaning the slider with Caig MCL and had no luck. Also did a D/A converter adjustment...back to square one..wondering if it could be a bad diode, op amp, or transistor.

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garranimal
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Re: Roland sh-101 LFO/CLK RATE problem

Post by garranimal » Fri Feb 19, 2016 5:39 am

Jonathan40 wrote:
garranimal wrote:Might try cleaning the slider with some contact cleaner.
I tried cleaning the slider with Caig MCL and had no luck. Also did a D/A converter adjustment...back to square one..wondering if it could be a bad diode, op amp, or transistor.
Cleaning doesn't always help, but worth a shot. If it were me, next step, I would de-solder the slider and test it with a DVM.

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Re: Roland sh-101 LFO/CLK RATE problem

Post by Jonathan40 » Sun Feb 21, 2016 8:04 pm

garranimal wrote:Cleaning doesn't always help, but worth a shot. If it were me, next step, I would de-solder the slider and test it with a DVM.
Think I'll be giving that a try, as the cap and a resistor in the circuit tested out OK. I tried comparing the ohms of the LFO/CLK slider to the other good ones while all were still attached to the board, but all are giving me a 0 ohm reading for some reason. Guess they'll need to be removed. Another possible fault could be the dual op amp in the circuit, or maybe one of the transistors, though I don't really know how they'd affect speed. Schematic: Image

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