>
> There were two VT220 designs (I think), using either an onboard or
> offboard flyback. The part number of the onboard flyback is 16-26299-01,
> and there are some available on eBay if you are feeling rich.
>
I don't want to hijack Rob's thread too much :-)
I actually have one of each design
osts' ; 'Mattis
> Lind'
> Subject: RE: VAXmate PSU fixed, but no video
>
> It is not my design, Tony Duell sent it to me and I think he got it from a
> magazine many years ago. I will try to find it.
>
> Regards
>
> Rob
>
> > -Original Message-
> >
n-Topic and Off-Topic Posts ; 'Mattis
> Lind'
> Subject: Re: VAXmate PSU fixed, but no video
>
> On 2020-04-18 11:09 AM, Rob Jarratt via cctalk wrote:
> > I checked Q6 (in circuit), it is not shorted. I have already checked all the
> electrolytic capacitors for a bad ESR
arning to design a pwm flyback controller which is
more or less the same thing in principle?
--Toby
>
>
> Regards
>
>
>
> Rob
>
>
>
> From: Mattis Lind
> Sent: 18 April 2020 13:31
> To: r...@jarratt.me.uk; Rob Jarratt ; General
> Discussion: On-T
Subject: Re: VAXmate PSU fixed, but no video
>
> >> 1. If the EHT lead was not properly connected to the CRT anode, could
> >> that cause problems?
> >
> > Possibly. I have VT220 terminal which was making a smell of ozone
> > when it was running whi
circuit some years ago). I don’t think you can do ring tests in
circuit can you?
Regards
Rob
From: Mattis Lind
Sent: 18 April 2020 13:31
To: r...@jarratt.me.uk; Rob Jarratt ; General
Discussion: On-Topic and Off-Topic Posts
Subject: Re: VAXmate PSU fixed, but no video
Den
> -Original Message-
> From: cctalk On Behalf Of Peter Coghlan
via
> cctalk
> Sent: 18 April 2020 12:57
> To: General Discussion: On-Topic and Off-Topic Posts
> Subject: Re: VAXmate PSU fixed, but no video
>
> >
> > Some of you may recall seeing me p
>
>
> One approach to testing flyback transformers seems to be to use a circuit
> that causes them to ring and observing whether the ringing is damped by
> shorted turns. I've never got around to trying this myself.
>
>
I have a VT100 that failed with some smoke coming out of the center of the
>> 1. If the EHT lead was not properly connected to the CRT anode, could
>> that cause problems?
>
> Possibly. I have VT220 terminal which was making a smell of ozone when it was
> running which I should have done something about but never got around to.
> This could have been due to corona
e finding
one. donberg.ie seem to have VT420 LOPT.
/Mattis
>
>
> I have posted about the PSU repair here:
>
>
>
>
> https://robs-old-computers.com/2020/04/18/vaxmate-h7270-psu-fixed-but-no-vid
> eo/
> <https://robs-old-computers.com/2020/04/18/vaxmate-h7270-psu-fixed-but-no-video/>
>
>
>
> Thanks
>
>
>
> Rob
>
>
>
>
ical description, what chance of finding a
> "modern" replacement?
>
I wish you good luck with this. I never had any luck locating one for my
VT220 :-(
Regards,
Peter Coghlan.
>
> I have posted about the PSU repair here:
>
>
>
> https://robs-old-computers.com/2020/04/18/vaxmate-h7270-psu-fixed-but-no-video/
>
>
>
> Thanks
>
>
>
> Rob
>
>
Some of you may recall seeing me post about the VAXmate PSU failure. Thanks
to members of this list I found the failed part in the PSU and the PSU is
now working again. However, it looks like the PSU failed because of a
failure on the monitor board. There is a burning smell coming from it,
12 matches
Mail list logo
