VT320 fault - flashing LED and no HT

From: Kevin Handy <kth_at_srv.net>
Date: Wed Dec 24 12:41:26 2003

TRASH3_at_splab.cas.neu.edu wrote:

>The LK201 keyboard is used across the 2xx, 3xx and on some of the 4xx
>terminals, so yes, as I remember, the vt220 keyboard will work with the
>vt320.
>
>
VT220 and VT320 keyboards were basically the same. The 420 added
a couble of new keys, but would work (except for the new keys) on the
older terminals.

>Can't help with the diagnostic. I am sitting in front of a VT330 now, and
>I just looked at the manual for it. it says if the power indicator flashes,
>check the ROM cartridge on the rear has to be inserted correctly. I didn't
>think the VT320 had a rom cartridge, so that troubleshooting probably
>won't help.
>
>
>
VT330?

The 320 doesn't normally have a ROM cartridge. The normal failure mode
for a 320 is the flyback transformer. It shorts out, overheats, cracks the
ceramic shell, and nasty brown stuff oozes out the cracks. Frequently it
would also take out the horizontal transister. Not too hard to replace, if
you can find new parts for a cheaper price than a complete 320.

Look at the flyback and see if you have the crack oozing brown goo.
It is the large white blob soldered to the electronics board, with
a heavy wire coming out the top and attaching to the side of the video
tube. Be careful playing with that wire, especially if you don't know
about video tubes, as there can be a extremely high voltage applied
to it even with the power turned off (>10,000 volts)!

>Joe Heck
>
>
Received on Wed Dec 24 2003 - 12:41:26 GMT