A Vintage Monitor Lives Again With A New Heart

Aside from keeping decades-old consumer-grade computing hardware working, a major problem for many retrocomputing enthusiasts lies in doing the same for vintage monitors. Whether your screen is a domestic TV or a dedicated monitor, the heat and voltage stress of driving a CRT made these devices significantly less reliable than many of their modern-day counterparts. [Adrian’s Digital Basement] has a worn-out and broken Commodore 1701 monitor, which he’s brought back to life with a modern circuit board and a CRT transplant.

Following on from a previous project, he’s using a replacement board sold as a repair option for CRT TVs on AliExpress. The Commodore monitor has its board on a metal chassis which takes the replacement with a bit of modification. He doesn’t say where the new CRT came from, but we’re guessing it was a late model TV as CRTs made over the last few decades are more interchangeable than might be expected. There’s a moment of mild dodginess as he makes a voltage doubler to run the 220 V board from 120 V with a pair of large electrolytic capacitors hot glued in place, but otherwise it’s a success.

At the end of it all after some testing and set-up he has a Commodore monitor with a new heart and multi-standard support. Is it really a Commodore monitor though, or should it have been repaired? It’s a difficult one to answer, but we’d suggest that CRT monitor repair is less easy today than it used to be because many of the parts are now difficult to find. If it saves at least some of the original from the dumpster it’s better than doing nothing. We wonder how long these upgrades will remain possible as even with Chinese plants making these boards and a handful of CRT TVs still appearing on AliBaba it’s clear that CRTs are at the very end of their life.

25 thoughts on “A Vintage Monitor Lives Again With A New Heart

    1. Well outside my skillset but I reckon there are a few people out there who could build a monochrome CRT, it’s ‘just’ a high voltage vacuum tube with phosphor, there’s no critical alignment needed in the assembly because there’s no shadowmask or aperture grille so good glassworking, mechanical assembly and vacuum skills would get you a fair way along, I reckon both Ron, Glasslinger, and Dalibor Farny would get there (ISTR Ron has already shown a basic CRT build?).

      Colour CRTs though, I think that’s a whole other level of manufacturing complexity for the gun assembly, never mind shadown mask or aperture grille, it’s difficult even if you go for an old 90 degree deflection Delta gun arrangement, 110 degree PIL and Trinitron would be harder still.

        1. Sure, it’s an LCD shutter as used in some Tektronix scopes, nice but not really a colour CRT and really a whole extra level of complex to manufacture over a ‘proper’ colour CRT.

          1. I was thinking that you could make the CRT yourself, since they aren’t being made anymore, and buy the LCD shutters, then bring it all together with a Pi and you have the closest you can get to a home made colour CRT.

      1. Trinitrons were throwaway trash designed to sell more TVs and kick start the war on our right to repair. Their pictures were never better than anyone else’s, Sony just used the power of advertising the way Apple does to sell inferior tech at premium prices as prestige items.

        1. That’s not how I remember it. I remember my old Trinitron that I bought used at a garage sale some time in the early to mid 1990s having the best picture in the house!

  1. I think one of the ultimate DIY flexes would be to replace the phosphor layer of an old CRT with a quantum dot layer… the challenge of that would intense but conceptually doable…

  2. Less reliable than their modern counterparts? Where did you get that ridiculous idea? When I was a preteen, in the early 90’s, we had a second hand Curtis Mathis black and white set in one of the rooms of the house. It was over 20 years old at the time and it never even blinked. Televisions have gotten less and less reliable ever since Sony designed the Trinitron. We didn’t have to buy new sets every 5 years back then, because they worked FOR DECADES. The older models with point to point wiring(before circuit boards made manufacturing cheaper and shorter lived) can be kept alive INDEFINITELY. The only things CRT TVs had to worry about was magnetic fields affecting the shadow mask causing colour banding and the occasional issue with power supplies(that every electronic device ever made has, to this day) and sometimes needing to adjust convergence.

    You really should LEARN about tech before trying to write about it.

    1. Old TVs did indeed fail at a fairly decent rate. I made a lot of money in the ’70s and ’80s repairing TVs (and VCRs) Back then, when a TV was a greater precentage of an average person’s salary, and when service data and parts were easily available, TV repair was a very lucrative business. Some time in the early ’80s I saw that this would come to an end and got a degree in electrical engineering so that when TVs were no longer being repaired I’d still have an income. A lot of my co-workers called me a chicken little, but by the early 90s, it was almost impossible to make the kind of money repairing TVs that was possible in the decades before that.

      1. Hold on, please wait a second.
        In that time frame, you surely still had to repair ancient TVs from the 50s/60s! That’s not fair for making a statement about reliability of CRTs!
        Tube radios of that time were equally unreliable.

        No, these old TVs were unreliable because of their lack of proper power supplies, or power supplies at all.

        Once TVs had their internal PSU from which they generated all the other voltages, they were much more reliable.

        Just look at camping TVs or portable TVs from tge 70s/80s.
        They have an optional 12v or 13,8v input, which means a power supply is at work. They’re insulated from AC mains, thus. Also, they had a cleaner and more modular design (circuit boards, plugs etc).

        What I mean to say is that it wasn’t the technology that was bad or immature.
        The CRT tubes and schematics weren’t that different from more recent times.
        It rather was the implementation that was making early sets unreliable.

    1. Yup. But as long as it makes people happy..

      I mean, the 1702 wasn’t THAT great.
      It was a decent video monitor, yes, but not spectacular.

      It was a semi-professional composite monitor, a reliable work horse.
      It was sometimes used by TV studios and video amateurs, for example.

      The stackable design and the many adjustments knobs behind the lid were really handy.

      But that’s it, pretty much.
      – Oh wait, the CRT dot pitch was nice too for game consoles, like the NES or C64.
      It’s a good monitor to watch VHS on, thus.

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