Qnic CGM 2500

JukeboxJon

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Donor 2016, 2025
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Hey guys could use some guidance from one of the Vets here on this one. Its a k7000 clone and actually very straightforward chassis. So started off it was missing the fuse its a 3A fuse i put in a SB because thats what the k7000 uses only 1.5 A SB. The manual dosent say. So after powering it on r901 a ceramic 1.5ohm 5watt resistor starts getting super hot and smokes. I replaced it even though I dont think there is anything wrong with the one i took out I didnt leave it run long enough to burn it up. I replaced the power regulator its uses the same one as k7000, dont think there was anything wrong with the one I took out. Tested the bridge rectifier diodes they all test good in circuit I think. Im not sure id they. Re suppose to only test like a diode on the negative side or both ways. Any other ideas?

Maybe a bad cap? I dont see any suspicious and i tested them for shorts. I guess I might as well order the cap kit and do that.


Here is the manual. All I can think is maybe shotgunning new bridge rectifier diodes?

 

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Well I check the HOT it has an odball one and it was reading shorted so I took it out and tested it and it tested fine, checked that the pad was in place and that was good and wasnt causing the short, so I put it back in, read good, fired it back up and it did something, almost acted like it tried to fire up, then nothing and back to r901 getting super hot and the HOT reads shorted again so IDK wtf is going on with this thing. Going to shotgun a capkit in it and see but if that dosent work @zenomorp you want to give it a go? would be a great video to add to your collection and its compatible with most 25" standard res tubes. The Qnic CGM 2500 was actually pretty common in Neo Geos and it has a full manual available.


I mean k7000 works fine on it, but where is the Science and fun in that!? Great looking tube too.
 

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