PDP-8 diagnostics SR settings?

[Charles]

Looks like I spoke too soon. The dreaded RL8A failure has returned!

I made a new OS/8 RL02 pack on vtserver (took the expected three hours at 
9600 baud console speed). Booted up the 8/A, so far so good.
But then Drive 0 faulted and OS/8 crashed... restarted and it crashed a few 
seconds later again.

I flexed the middle of the RL8A upwards and the system worked. For a while. 
Then it crashed and wouldn't reboot.
Back to where I was earlier in the week - won't even allow SerialDisk to 
boot if the RL8A is in the backplane. OS/8 on the SerialDisk virtual RK05 
works flawlessly if the card is removed.

Obviously there is still an intermittent which has come back. Maybe there's 
a tiny thread of something conductive stuck under one of the IC's and I 
managed to temporarily clear it as I described.
Anyhow I am resuming my search for a good RL8A. I have wasted enough 
man-hours on this flaky board.

thanks
Charles