Golden Axe rebuild: I think I figured something out with my width problem.

Jaak

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As many of you know I have been having a problem getting the width of my 19k7000 to play nice with over four 19 inch tubes over the last six months or so. Well today I think I found my problem.

First let me say that this is my first foray into rebuilding any arcade game and I knew nothing at all about CRT tubes and the chassis that drive them. I managed to luck into three k7000 boards in terrible non working condition when I picked up the decrepit Golden Axe in question. I chose the cleanest of the three boards and used the other two as parts donors. None of them had a good flyback that was not arcing, so that was replace with one from Arcade Parts and Repair. I also ended up having to replace a physically snapped width coil.

Well at that time I had no idea there were two types of k7000 boards. It turned out that I had one 19k7000 and two 25k7000s. I wanted to use one of the boards to drive a19 inch tube and completely lucked out when I started rebuilding the 19 inch board. I also unluckily was scavenging parts from the two 25 inch boards. I ended up scavenging the width coil from one of the donor boards and installed it into the 19 inch board.

I had later learned that there are two sizes of k7000 cassis and completely forgot that I had to replace the width coil on my 19 inch. This realization literally came to me in a dream. I woke up this morning and the first thing out of my mouth was morning breath and "SONOVABITCH!"

I did some reading and found that the width coil for the 25 inch version of the k7000 has an inductance range of 29uH to 250uH. The 19's range is only 15uH to 125uH. I took the width coil of and unwound loops until I got close enough.

I've run out of time at this point and I'm going to install everything tomorrow and test. Wish me luck!
 

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Well, it made a difference, but didn't solve the problem completely. I'm back to hunting more 19s.
 
So this was a mistake. I was completely wrong about the 19k7000 having a lower inductance range on its width coil. It has a much higher range. Ignore anything I've said before.
 
I managed to source two original width coils and tested the inductance ranges.

Coil #1 61uF to 554uF
Coil #2 62uF to 544uF

Based on these two readings I think a datasheet world claim an inductance ranges of 60uF to 550uF.

I hope this is useful to someone in the future.
 
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