On Sep 20, 2016, at 12:49 PM, Julian Wolfe <j...@lolqb.us> wrote:
> So the DSD-440 I got at VCF is completely unresponsive. All of the LEDs are
> on and never go out, which is bizarre - they are supposed to go out in 1/10
> of a second after power on.
> I tried disconnecting everything but power to the card, and it still lights
> all LEDs. No jumpers that I could find are in the wrong spot, but many are
> seemingly undocumented ( I looked in both the 1981 user manual and 1984
> service manual on Bitsavers).
> The drive just spins and does nothing else. Altering the switches on the
> control board do nothing to change the state of the LEDs
> I measured voltages at the power supply, and they seem to be within spec
> according to the manual.
> Are there any other things I can try before I start digging into things on a
> component level?
This is a failure of the DC Power Up/Down circuit - See page 3-10 + 3-53/54
in June 83
Service Manual. If the components in this circuit (capacitor) are out of
spec, then this may be the cause.
Congrats on picking it up. I was tempted to bid for it as well, but I already
filled had my boat anchor quota.
Is the Green LED on?