Discharging a VT100 CRT
fireflyst at earthlink.net
Thu Nov 10 17:50:22 CST 2005
I have a few things I'd like to share with those who've been following this
First, a question: Will this work as a replacement cap? It took me a while
to find this:
Secondly, apparently my old VT100 outlasted someone's VT101 with the same
problem by 12 years:
From: BJJ at ECL.PSU.EDU (Bryan J Jensen)
Subject: Re: VT101 video woes...
Date: 23 Jul 1993 05:00:39 GMT
Organization: Penn State Engineering Computer Lab
Message-ID: <22nr9n$orj at genesis.ait.psu.edu>
References: <CAAKnF.4qA at rice.edu>
In-Reply-To: adam at owlnet.rice.edu's message of Sat, 17 Jul 1993 04:33:15 GMT
In <CAAKnF.4qA at rice.edu> adam at owlnet.rice.edu writes:
> I have a lovely old VT101 sitting here that I inherited.
> ... I get nada on the video.
The video board is the one to the side of the CRT with all the pots.
On the video board, The 75uF, 6V capacitor C439 and its neighbor,
diode CR408, have a real bad habit of burning up.
The Flyback transformer or Horizontal Output Transistor sometimes
go bad too, of course, as they seem to in any monitor. I forget
where the transistor is.
From: cctalk-bounces at classiccmp.org [mailto:cctalk-bounces at classiccmp.org]
On Behalf Of Chuck Guzis
Sent: Thursday, November 10, 2005 4:45 PM
To: cctalk at classiccmp.org
Subject: RE: Discharging a VT100 CRT
On 11/10/2005 at 4:50 PM Allison wrote:
>The cap I'd likely hunt around for a junk radio or computer monitor
>chassis and pull it from there.
Largely OT: Another place to look is in the bases of compact
fluorescents-incandescent lamp substitutes. In the US, you can usually
find a couple of 22 or 33 ufd @ 200v caps, a bunch of diodes and
miscellaneous small caps, a small toroid and two TO-220 power transistors
of the MJE13005 variety. The latter can be very useful for deflection or
switching PSU replacements as they're rated at 4A/300-400v with a t(f) of
less than a microsecond.
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