Hantarex mtc 900e Rainbow colors, desperate for help!

MegaChundler

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Hantarex mtc 900e Rainbow colors, desperate for help!

This is a long story, so I'll try to cut to the chase. I bought an Operation Wolf arcade almost a year ago for a good price, which played blind but had a dead monitor. I decided to make it my first monitor project, and learned a huge amount, mostly from reading you guys on here, which I'm very grateful for! Anyways, I recapped, installed a new flyback, and replaced the largest wire wound resistor which was broken. I finally got the thing to power up, and to show the images on the monitor as the game played..... the issue is that the colors are all rainbow! And before you ask, yes, I degaussed with the degaussing coil several times without any effect whatsoever.

Another point that may be of interest, is that the neckboard snaps and pops (arcing, I can see it with the light off) while the games boots up. It used to do this constantly, until I turned down the B+ voltage, but still pops at startup for about 10 seconds. My concern is that the neckboard is not properly grounded. It is connected to the DAG wire, but nothing else.
Any help is greatly appreciated! Thanks guys!
 
did you use the coil that is part of the monitor or did you use an external degaussing coil and what was the procedure you used? I have had some seriously bad monitors that the attached coil could not fix but cleared up greatly by using my bulk eraser on it.
 
Thanks for the reply!

I'm referring to an external degaussing coil ($50 on eBay). I used a couple of methods, basically starting near the screen and doing larger circles with the cool and backing away until I'm about ten feet away. Had absolutely no effect after a few attempts.
 
so you watched the colors move all over the screen while you wee moving the coil? I just want to make sure that the coil was working properly. I don't like to assume anything it always bites me later.
 
I don't remember if these used the bonded yokes like the later Polos, but if the yoke isn't bonded, I would try turning it. you shouldn't be able to; if you can turn the yoke then that means it was loosened at some point. if this is the case and the yoke slides backward away from the tube and down the neck, you can arrive at the magnetized effect. this will probably show up as discolored lines across the screen, or like a rainbow effect. (the picture would be nice)

if your discolored splotches are in one concentrated area on the screen, then that's probably a bad purity adjustment. if the convergence rings were loosened and moved, this can cause this too. you can usually tell by the dust/dirt on the neck where they're supposed to go if they've moved around.

the last thing with the convergence rings is to check that the seal is still across them. if it is, then the rings were never moved from their factory adjustment. if not, then you're going to be in a world of pain. a telltale indicator that the rings were futzed with however is in the convergence itself; if the screen has poor convergence, either the whole ring assembly moved or someone tinkered with the rings.
 
Here's a video of what I'm talking about
https://m.youtube.com/watch?feature=youtu.be&v=ytUfrHqZ6GM

Here's a picture of the board, but it's an old pic before I replaced the caps and

Yes, while using the degaussing coil I could see a slight change in color, but nothing changed permanently.

Mecha, I will check the yoke again, but if I remember right, I tried to see if it was loose in the past and it was pretty stuck in place. I'll double check this.

Thanks for the feedback guys
 
holy crap
that thing is right out of foucs (turn it down) + plus your screen is to high (turn it down)
mech it looks like u nailed it (converg rings)

ed
 
So I checked the rings, and it still had the factory glue on the convergence rings, and a white painted line that all lined up... the yoke barely moves at all when I try. Doesn't make sense that the convergence rings would all be out of wack if they still had the glue and appeared to be lined up from the factory.
 
ya they look fine
did u chk your screen and foucs (on the flyback)
and a question here
why did u mount that load resister that way ?
as it will induce ripple into your requlator
i sujest u mount it with a screw and nut on the heat sink and run proper wire to either end

ed
 
Any more ideas? Could it be that the convergence rings are out of wack, even though they appear to be factory set?
 
I mounted the wire wound resistor on there as a temporary set up until I could get it bolted in place. If I adjust the focus on the flyback, it causes the arcing on the neckboard to get worse.
 
if u are turning the foucs down to get a good foucs and u get arching on the neck board ?
then either your tube socket is shot (common)
or your tube has a slow leak
or your ground is all wrong (which btw will cause the color problems)

ed
 
I have a suspicion that my grounding is messed up. My neckboard is connected to the DAG wire, but the neckboard isn't connected to the metal frame of the chassis at all. I'm not exactly sure how to correct this. How can I ensure a good ground from the neckboard to the chassis frame?
 
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