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Can anyone diagnose my CRT image?

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  • Can anyone diagnose my CRT image?

    Hi all, super happy with my new (old) cabinet pick up, LAI with a Kortek chassis i think, even though i don't know the model.

    The image and colours generally look great but I have some weird interference going on which appears to be manifesting as white squiggly lines across the image, this is without the JAMMA harness plugged in so you can just see the raw monitor picture to make it easier to see whats happening.

    The video also shows the refresh rate difference across the screen, but im trying to show the white dotted lines.



    Would love the friendly experts to see if they can offer an opinion and maybe some advice, thanks so much!
    Last edited by zer0entity; 20 September 2019, 10:26 PM.

  • #2
    Possible bad earth
    More likely eht spray
    Any arcing going under yoke cap ?
    Any arcing around fbt ?
    Check neck board ground connection ro crt earth strap
    Pinball, Its an Addiction

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    • #3
      Thanks Ando. Can I ask what eht spray is?
      And also, what am I looking for when checking Ground and Earth connections?
      From a noobs point of view nothing looks out of place or weird around the back but I need to know what I'm looking for. I understand not to go poking my hand around the monitor so any further advice would be appreciated.

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      • #4
        Originally posted by zer0entity View Post
        Thanks Ando. Can I ask what eht spray is?
        And also, what am I looking for when checking Ground and Earth connections?
        From a noobs point of view nothing looks out of place or weird around the back but I need to know what I'm looking for. I understand not to go poking my hand around the monitor so any further advice would be appreciated.
        You said you've re-capped the chassis, what caps did you use?

        Personally, your best option is to send your chassis to [MENTION=204]Jomac[/MENTION] and get him to go over it for you.

        The only issue you might have is you've now attempted to repair the chassis yourself.

        Have a chat to Joey (Jomac) and see what he suggests.

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        • #5
          Hi mate no I haven't attempted anything at all, sorry if you misunderstood! Literally just asking questions at the moment!

          I would be honoured to summon the mighty [MENTION=204]Jomac[/MENTION] even just for some advice on here, thanks!

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          • #6
            Originally posted by zer0entity View Post
            Hi mate no I haven't attempted anything at all, sorry if you misunderstood! Literally just asking questions at the moment!

            I would be honoured to summon the mighty [MENTION=204]Jomac[/MENTION] even just for some advice on here, thanks!
            Drop him a PM.

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            • #7
              Cheers, will do!

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              • #8
                Originally posted by zer0entity View Post
                Thanks Ando. Can I ask what eht spray is?
                And also, what am I looking for when checking Ground and Earth connections?
                From a noobs point of view nothing looks out of place or weird around the back but I need to know what I'm looking for. I understand not to go poking my hand around the monitor so any further advice would be appreciated.
                Extra High Tension, Around 28000 Volts comes from the flyback transformer to the CRT anode cap, ( that black rubber cap ) Be careful it can hold a charge even when power is off. The spray is arcing you can usually hear it, sometimes smell it. Very common in seaside environments.

                There should be an earth strap around CRT that connect to the neck PCB make sure this is sound and circuit is complete.

                Take care around High Voltage
                As John mention Joey is excellent if you are really stuck.
                Pinball, Its an Addiction

                Comment


                • #9
                  Originally posted by Ando77 View Post
                  Extra High Tension, Around 28000 Volts comes from the flyback transformer to the CRT anode cap, ( that black rubber cap ) Be careful it can hold a charge even when power is off. The spray is arcing you can usually hear it, sometimes smell it. Very common in seaside environments.

                  There should be an earth strap around CRT that connect to the neck PCB make sure this is sound and circuit is complete.

                  Take care around High Voltage
                  As John mention Joey is excellent if you are really stuck.
                  Thank you for your expertise [MENTION=1636]Ando77[/MENTION] i really appreciate it. I have identified the parts you have mentioned. I can't see or smell anything out of the ordinary so that's good. I'm not about to go poking around though, JAMMA wiring is one thing, 240 Volt CRT's are another. I have contacted Jomac so will see if I hear anything back. I notice there seems to be a wire coming from the transformer at the bottom of the cab which runs to the big metal coin box, I assume that's as it should be and adjusting that wouldn't change/fix the issue? That's the only thing i'm willing to do myself.

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                  • #10
                    This looks more like a Grounding or Earthing issue , in this thread I explain pretty everything it can be , the same applies to all sorts of interference on CRT's , yours fits perfectly into category.
                    http://www.aussiearcade.com.au/showt...ht=#post773846

                    Not problem if you find the chassis is faulty I can sort that out for you.

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                    • #11
                      Just replied to your PM Joey.
                      AA is full of really helpful folks and it's fantastic, I'll keep you all updated on my machines progress, cheers!

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