> Hi all, > > A colleague and I are trying to get a VT220 working again as it recently > died on us. We are hoping to set up a few items for the mid-80s > (including this terminal) to show the graduands what it would have been > like if they were doing their CompSci degree 30 years ago. > > It looks to me like the flyback is dead. There is a lot of soot and > there looks like there is some damage to the top of the transformer, > better seen in the second image. > > http://www.cs.nott.ac.uk/~psxasj/sparse/flyback1.jpg > http://www.cs.nott.ac.uk/~psxasj/sparse/flyback2.jpg >
I think the soot is fairly typical of what accumulates on high voltage components in a city environment. I'm not sure this indicates any damage to it but it may well be faulty without showing any signs of damage. > > The terminal powers on and does the usual beeping but nothing is > displayed on the screen. Does anyone have any advice about what to do > here? Are there any sources of compatible flyback transformers? > I have a VT220 which also appears to have a faulty flyback. This results in it drawing too much current from the power supply. I am not certain the flyback is faulty but I have eliminated most of the other components which are likely to be responsible. I have looked for replacement flybacks or equivelants but I have never found any. Someone mentioned that they might have VT220 parts available on the list some time ago but I didn't get anywhere in following that up. > > We have a second VT220 which exhibits the same behaviour, hopefully for > a different reason so we can try and cobble two into one. > I have a second VT220 which works and I have used it to compare readings with my faulty one. I also tried swapping some of the suspect components but this failed to take suspicion off the flyback. I am reluctant to try swapping the flybacks over in case I cause damage to the working VT220. While the two flybacks appear likely to be electrically similar, I am not certain of this and they are physically different - one is PCB mounted and the other is chassis mounted with flying leads to the PCB as far as I recall. They have different part numbers, 16-21181-01 and 16-26299-01. > > Any thoughts / advice would be greatly appreciated. > Sorry, I haven't been able to provide much help or hope. Regards, Peter Coghlan > > Thanks, > > Aaron. > > > > -- > Aaron Jackson > PhD Student, Computer Vision Laboratory > http://cs.nott.ac.uk/~psxasj