VT220 symptom

[Kevin Handy]

9000 VAX wrote:

>Hi, list,
>  My VT220 went crazy yestoday. When I was doing something else on my
>PC, suddenly the VT220 monitor was blank (black) and the LEDs on the
>monitor flashed. The frequency was about 4 or 5 times a second. The
>keyboard LEDs (LK201) flashed the same speed as the monitor LED.
>Taking off the keyboard and the RS232 port did not solve the problem.
>Does anybody know what happened? Is there an easy way to fix the
>problem? Thanks.
>  
>
Most likely problem: your flyback shorted out.

DEC used lousy flyback transformers, and they were always my
biggest problem with all the VT terminals. They would short
out (cracking the ceramic shell and oozing black goo that would
then harden), and often taking out a driver transister too.

You can repair this problem with a new flyback (probably
going to be hard to find), and a new transister.  Been there,
done that (many times), got the T-shirt.