[sdiy] troubleshooting a LFO

[Metrophage]

I'd use an audio cable made from a jack on one side, and clips on the
other. Connect the ground to ground, and then try the signal clip in
the LFO circuit to hear whether or not it is woking. There is not much
which can break in an LFO circuit! If the LFO works then I'd trace its
connection to the other modules.

As usual, broken solder joints and stiff interconnect cables are the
primary suspects.

CJ


--- luna <junk at lunarising.com> wrote:

> hello everyone, i've just subscribed, and it looks like the sh-101 is
> a 
> current topic so...
> 
> i just recently bought a roland sh-101 with a non-working LFO,
> thinking 
> that the slider was dead. but it looks like the slider is
> operational, so 
> something else is wrong with the LFO. so here's how it looks:
> 
> LFO light on the sh-101 is always on; all modulations work to VCF and
> VCO, 
> but the impact is static. the LFO isn't 'moving'. i know that the EXT
> Clock 
> in still works with the sequencer and arpeggiator and changing the
> sample 
> and hold, so it is hopefully not a CPU issue. it just looks like the
> LFO is 
> dead. although i'm not new to a soldering iron and construction (have
> made 
> a fatman and a number of effects), troubleshooting and LFO/oscillator
> 
> design theory is a bit new to me. my question is, what should i look
> for to 
> identify what is the problem in the circuit, if indeed it is not a
> CPU issue?
> 
> any help is appreciated, as i would love to use the sequencer as 
> standalone, not to mention having a LFO for modulation ;)
> 
> also, schematics are located here: http://tinyurl.com/6ktq9
> 
> thanks in advance.
> 
> 



		
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