I've had some bad luck too in getting the exact voltages. After
replacing all dual opamps, things got a bit better but still not
100% according to spec. On my CS80 I didn't get some of the voltages
(pin13 ic2; pin6 ic3, pin38 ic2) to spec even when I checked the
power supply and had the TU at exactly 4.000V. However, ignoring
this and after performing all the following steps (S/H + M-boards)I
had my CS80 perfectly in tune on all ranges. I didn't realise pin 13
and 38 interact with eachother, maybe I should try again and see if
I can get everything according to spec then. Still I guess it will
not help. Especially pin 6 ic3 was way off spec. Maybe some aged
components are causing this ?
--- In
yamahacs80@yahoogroups.com, "kent_spong" <kent_spong@...>
wrote:
>
> Hi,
>
> In my book that would be step 4.
>
> Before you do anything make sure the tune pot is centered trim the
> power supply, then check the TU pin on the KAS for 4.00 volts.
>
> Then pin 6 of the lm310 for 0.125 volts holding down bottom C.
>
> You need to check pin 38 as well as pin 13 on the YM2700 as one
will
> effect the other.
>
> If you still get no luck let me know.
>
> Kent
>
>