I recently bought an Atari SM144 monochrome monitor so I could play with an old Atari ST. It works to a certain degree, it turns on all good and I can play for a while, but after some time it gives off an ionising/burning smell.

It working (ignore the refresh rate discrepancy, it's a solid picture my end)

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Then after let's say 5-10 minutes, maybe less if I turn off the monitor by the switch on the front, and then turn it back on, I get lines like the following

enter image description here

Any ideas what this could be?

  • 3
    Sounds like one or more broken solder points. The ozone smell could indicate that the problem is in the high voltage part of the system. Nothing I would recommend to try to fix yourself. Opening a CRT is really only for those who know exactly what they are doing.
    – UncleBod
    Nov 14, 2022 at 15:49
  • 1
    I've already had it to bits cleaned and replaced most of the capacitors @UncleBod Nov 14, 2022 at 15:57
  • 1
    Replaced like for like @Justme. The capacitance reading was low on a few of them, nothing drastic. Was more just an excuse to use my new solder 😂 Nov 15, 2022 at 9:15
  • 1
    yeah the behaviour is exactly the same as before/after the recapping. @Justme I.e the turning off/on problem causing the striped screen. Nov 15, 2022 at 11:04
  • 2
    That's fair enough, I posted the question to see if anybody had had the same issue as me and could point me in the right direction. @thebusybee Nov 15, 2022 at 15:58


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