Need help: DSD-440 with unresponsive formatter/control board

[Jerry Weiss]

On Sep 20, 2016, at 12:49 PM, Julian Wolfe <jrw at lolqb.us> wrote:
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> 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.
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> 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).
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> 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.
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> 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