Amplifone monitor advice

Black Matrix

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Hey Guys,
I have a 25" Star Wars CP that has been the bain of my existence for a couple years now. I had rebuilt the monitor with all the Bob Roberts kits and got it working well. Even left it on for 24 hours accidentally once and it was still working when I came back. Recently, I went out to work on a Tron that was on the same plug as the SW. When I plugged them in, I started hearing popping/cracking. Unplugged everything thinking it was the Tron. When I reapplied power, I think the Transister at Q3 was beginning to smoke, but I can't quite be sure. Finally got up the courage to plug it in today and found that Flyback was arcing to the focus controls next to the flyback or the wires near it. My question is could the Q3 be causing my problems or is there a more likely culprit. I also just found one of the 3 black wires(that lead to the neck) on the corner opposite of the flyback has come loose. I suppose it could have shorted something, but I hadn't noticed it before. Any suggestions as to what to try. I don't think I have lost the flyback yet or it wouldn't be arcing. I'll have to check if the Q3 came with the monitor cap rebuild kit. If not, the extended burn test, could have put it on the brink of failure. Plus the large ceramic resister 22ohm has also seen better days. Mostly just looking for suggestions from people who have more experience on these than me. Could the Deflector board be causing this. The PCB also has a mathbox error, but I don't think that would have done it. Thanks in advance.
 
If your flyback is arcing, it likely has a crack in it. I doubt it has anything to do with the deflection board. Id pull it, check for anything that looks not soldered perfectly, and any burn marks, you might get lucky finding something loose.

Andrew
 
Mathbox error has nothing to do with it. You should check your voltages coming out of the deflection board and see if you have your + and - 30 at pins 7 and 8, pin 6 is your ground ( going off memory, pretty sure that is correct, might be backwards on what pin is +30 and what pin is -30 but it will be obvious when you check it). Could be that the black wire was touching something and causing an arc. You really need to just rebuild both of those boards per the FAQ.
 
I have rebuilt both boards, but the rebuilds don't include all the parts. It may have been the black wire which I will fix shortly. But the flyback is a nearly brand new cinelabs. It shouldn't be cracked after 48 hours of use tops. I'll check the deflection, but I think it should be fine. Just got to figure out this high voltage. But the fact that it is arcing at all makes me think its still good. However, it was in an outbuilding and it did have some condensation on it when I plugged it in last. It may be as simple as that.
 
I have rebuilt both boards, but the rebuilds don't include all the parts. It may have been the black wire which I will fix shortly. But the flyback is a nearly brand new cinelabs. It shouldn't be cracked after 48 hours of use tops. I'll check the deflection, but I think it should be fine. Just got to figure out this high voltage. But the fact that it is arcing at all makes me think its still good. However, it was in an outbuilding and it did have some condensation on it when I plugged it in last. It may be as simple as that.

Everyone repeat after me - Man made bound to fail
I had a brand new Cinelabs flyback that ALMOST split the casing all the way around. It had no more than 10 hours on it. I still use those flybacks because I've otherwise had zero problems with them.

Can I assume you own a HV probe? If you're going to be working on vector monitors IMHO it is a MUST have item. If you just rebuilt this how do you know how many Kv this is producing? I suppose a person could check the B+ and get it relatively close, but you HAVE to readjust the HV section when replacing a flyback.
 
What kind of voltage is an Ampliphone pushing. Would a 30K voltage probe suffice. Did the b+ thing first time, but that hasn't lasted. I may have to pick one up soon if its a necessity. Plus it should make it easier to test regular monitor fly backs as well.
 
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