HP 2648 terminal

From: Tony Duell <ard_at_p850ug1.demon.co.uk>
Date: Wed Feb 16 17:56:06 2005

>
> Ok, finished all negotiations with the seller. Turns out I get to keep the
> damaged unit.

Good...

[...]

> If anyone has the above parts, please let me know. This all assumes my tube
> is working. It looks like it's undamaged but I won't know till I power it
> up.

It's possible there's been damage to the electronics that you've not
spotted, so I would be careful when powering it up. If you've got a
cracked trace in the PSU, the output could go through the roof [1].

This is one time where you _certainly_ should test the PSU on dummy load
and add things in small incrememnts. Is it possible to run it without the
CRT and either get a beep and/or check the video and sync signals with a
'scope/ At least you'd then know that the digital side was working.

[1] I acutlaly had this in a piece of HP hardware. The connection to the
output capacitor in a swithcing regualtor was dry-jointed. The result was
15V spikes on the 5V line. Fortunately the crowbar tripped and saved the
logic, but I wouldn't want to depend on that!

-tony
Received on Wed Feb 16 2005 - 17:56:06 GMT