DEC H7260 PSU fault

[Jules Richardson]

On 01/27/2018 04:02 PM, Ethan Dicks wrote:
> On Sat, Jan 27, 2018 at 4:34 PM, Jules Richardson via cctalk
> <cctalk at classiccmp.org> wrote:
>> Success!
>
>
> Congratulations!

ish... :-)

It seems that my DHV11 board is bad - the system stalls on the PSU tests 
with it plugged in.

The TK50 drive sits there with a rapidly-flashing light (I saw someone 
saying that's likely the tape feed band or just dirty heads, so it might be 
fixable).

The RD53 drive... hmm. I tried powering it without it plugged in, just to 
see if it at least sounded healthy; it spun up to a "sensible-sounding" 
speed for maybe 15 seconds, then spun down again. I tried again, and it 
remained spun-up, but the initial spin-down was hardly encouraging.

With the drive actually hooked up to the controller, I'm getting "?54 
RETRY" messages when it's trying to boot - however, I'm not entirely sure 
what device it's trying to boot from! Maybe it's attempting the TK50, or 
via Ethernet. I still need to read up on that and work out how to force it 
to attempt a disk boot.

One other issue is that the RD53 was in the second bay (and hooked up to 
the associated cables) - it makes me wonder if it was just an auxiliary 
disk, and the system originally had another drive in the first bay 
(containing actual OS) which has been removed.

> Just be sure to follow the grant chain

Yup, I *think* I've got my head around how that works! (along with the 
special slots for CPU/RAM)

cheers

Jules