> -----Original Message-----
> From: Tony Duell <[email protected]>
> Sent: 01 March 2026 08:34
> To: [email protected]; General Discussion: On-Topic and Off-Topic Posts
> <[email protected]>
> Cc: Rob Jarratt <[email protected]>
> Subject: Re: [cctalk] Re: Identifying This Component from VT100 Monitor
> Board
>
> On Sun, Mar 1, 2026 at 8:28 AM Rob Jarratt via cctalk <[email protected]>
> wrote:
>
> > However, I have a VT101 and a VT102, one of them at least uses the same
> Elston monitor and a different monitor board (not with Germanium
> transistors). I could temporarily swap the monitor board to see if the flyback
> on the VT100 is still good.But, I am worried about damaging a perfectly good
> monitor board. If the flyback is shorted, could I damage the good monitor
> board?
>
> Yes (and it's one of many reasons why I am against board-swapping). If there
> are shorted turns in the flyback transformer you will almost certainly destroy
> the horizontal output transistor almost instantly at switch-on.
>
> Conversely, shorted diodes or capacitors on the PCB could burn out a good
> flyback transformer, but it's normally less quick than the flyback damaging
> the
> transistor.
>
> I would do a ringing test on the flyback transformer now. If it's good then
> repair the existing monitor board, check all the diode/capacitor circuits fed
> from the flyback on said board and then you just have to hope...
>
Ok, thanks for the advice. I will take it slowly.
Rob
