[cctalk] Re: Identifying This Component from VT100 Monitor Board

-----Original Message----- From: Tony Duell <ard.p850ug1(a)gmail.com> Sent: 01 March 2026 08:34 To: rob(a)jarratt.me.uk; General Discussion: On-Topic and Off-Topic Posts <cctalk(a)classiccmp.org> Cc: Rob Jarratt <robert.jarratt(a)ntlworld.com> Subject: Re: [cctalk] Re: Identifying This Component from VT100 Monitor Board On Sun, Mar 1, 2026 at 8:28 AM Rob Jarratt via cctalk <cctalk(a)classiccmp.org> wrote: 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...