20 Sep
2016
20 Sep
'16
11:34 a.m.
On Sep 20, 2016, at 12:49 PM, Julian Wolfe <jrw at 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?
Jerry