K7401 Recap now ticking and a cap went POP

tenjuna

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I haven't dived into troubleshooting yet, but I have been researching and it seems K7401 monitors are notorious for having issues after a recap.

Aside from the possibility I installed a cap wrong (which I have not checked yet), does anyone have any tips or tricks for these things or experienced the same kind of issue with a resolution?

I will troubleshoot after I move to Texas, or maybe I will just buy another chassis and/or monitor if this thing is really that sensitive.
 
Cap popping is because it was installed backwards; depending on model the silkscreen can be wrong.
 
I haven't dived into troubleshooting yet, but I have been researching and it seems K7401 monitors are notorious for having issues after a recap.

Aside from the possibility I installed a cap wrong (which I have not checked yet), does anyone have any tips or tricks for these things or experienced the same kind of issue with a resolution?

I will troubleshoot after I move to Texas, or maybe I will just buy another chassis and/or monitor if this thing is really that sensitive.
I've never had this problem. I've also never heard of some epidemic of people killing K7400s with cap kits. you need more of these videos in your life: https://www.youtube.com/@MikesArcadeMonitorRepair

Cap popping is because it was installed backwards; depending on model the silkscreen can be wrong.
I've never observed this on a Wells-Gardner monitor.
 
I've never observed this on a Wells-Gardner monitor.
Correct; I was not being specific again. I believe I heard in the past G07 had at least 1 incorrect marking. I was speaking more to observing the caps vs. depending on the silkscreen.
 
Correct; I was not being specific again. I believe I heard in the past G07 had at least 1 incorrect marking. I was speaking more to observing the caps vs. depending on the silkscreen.
oh yeah C302. funny enough I've never installed that cap backwards. LOL

and yes, you should always pay attention to how the old part was installed. I don't think it happens often but there's some people that go removing every single cap at once and I _strongly_ discourage doing that.
 
Understood, I did in fact double check alignment before installing each cap (which I do one at a time), but I assume I messed something up.

I was referring more to the ticking sound, which appears to have a lot of articles and videos about but not much on WHY it happens. I also suppose that if I installed something wrong that it could have unintended consequences, I guess I was just pre-emptively looking for other solutions.

And to be fair, I do watch Mike's Arcade videos :)
 
While it might help to know which cap popped, your troubleshooting odyssey should begin with checking whether you have a power supply problem or a horizontal circuit problem. Mike has done a couple of videos about this. The light bulb test and the frequency of the ticking can be used to help identify, in general, which circuit is suspect.
If you haven't already seen this one, check it out:

As for why the ticking sound happens, it is an indication the the voltage is trying to come up, but something is causing the monitor to shut down. Commonly caused by an overload in the horizontal section (a short, for example), a power supply component failure, the shutdown circuit activating due to miss-adjustment, or excessive high voltage. Lots of info about the theory of operation and failure modes on the internet. Since arcade monitors are basically just stripped-down television chassis (minus the RF input, IF and chroma sections), check some of the TV theory sites for even more info.

Best of luck.
 
I haven't dived into troubleshooting yet, but I have been researching and it seems K7401 monitors are notorious for having issues after a recap.

Aside from the possibility I installed a cap wrong (which I have not checked yet), does anyone have any tips or tricks for these things or experienced the same kind of issue with a resolution?

I will troubleshoot after I move to Texas, or maybe I will just buy another chassis and/or monitor if this thing is really that sensitive.
Without details, I would say you installed a cap backwards or incorrect value which caused it to vent (pop). The cap was somewhere in the SMPS or HV circuit causing the monitor to shutdown (tick).
 
Without details, I would say you installed a cap backwards or incorrect value which caused it to vent (pop). The cap was somewhere in the SMPS or HV circuit causing the monitor to shutdown (tick).
I of course had to assume the ticking was related, but this helps thank you. I am going to come back to this one after I move here in a few weeks.
 
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