Vintage Synth Repair

Duncan / All,

Yes, in the LFO Modulation section, all seven destination LEDs light up:
OSC1 Freq, OSC2 Freq, OSC3 Freq, PW1, PW2, PW3 and Filter.

However, turning up MODULATION AMOUNT (knob on left) and/or MOD WHEEL has NO effect EXCEPT on Filter - which works fine so I know the LFO is working.

Which board should I be checking?
-LOTS

--- In vintagesynthrepair@yahoogroups.com, "duncan" <ferrograph@...> wrote:
>
> >>But upon further investigation, I determined that the LFO Freq Mod of OSCs 1, 2 and 3 was NOT working.<<
> 
> if you have the schemos, the next thing to do is find a local tech who can follow them better than you... :-)
> it sounds as though there's a failure of the IC-based switchgear associated with the mod routing.
> the switches under the LFO rate knob will create a path from the LFO onto the three oscillators using analog switch ICs...
> 
> um....
> 
> do the LEDs still come on? I will dig out the schemos for my LAMM this weekend & see if I can get you a bit closer.
> 
> duncan.
>