Hantarex MTC9000 chassis help

[qjuk]

The B+ is 132.7v so that seems to be fine.

I notice there does not seem to be any static buildup when you turn on the monitor.

I’ll have some more time over the weekend, so I’ll get out the HV probe and see what the HT voltage is reading and if it is stable and take it from there.

 

[Retroman839]

I read that a term called
“Doming “ from either an impact
Or from heat causing the shadow mask to warp because of a lesser quality metal used In the shadow mask ?

The distortion caused in the mask from over heating misdirects the guns ..

Abouve image looks like almost 4 separate bubbles bottom right bulging the most ..

I just don’t understand how you can get this image then get a good image after some minutes Warming up unless it’s your shadow mask getting heat then reforming back to its correct shape / position .

Them guns should all be coming through together.

4 separate magnetic fields ?

Yoke ?

 

[qjuk]

That image above was caused by a bad focus connection due to the socket on the neck board.
When I replaced the socket, that picture no longer appears.
The screen from cold now starts up out of focus (but you can just about make out the game image) and the brightness is dim, when it warms up everything looks sharp and great, however something is clicking/arcing (I can’t be 100% sure) as I can’t find where it’s coming from.

The other thing that is concerning me is that the large 30w resistor is getting really hot and there’s no static buildup when you power it on. I’m now thinking it’s the LOPT (flyback) that’s the issue.

Next step is measure the HV when I’ve got a spare moment. If that looks suspect, I’ll be replacing the LOPT

 

[wheeeeel]

That image above was caused by a bad focus connection due to the socket on the neck board.
When I replaced the socket, that picture no longer appears.
The screen from cold now starts up out of focus (but you can just about make out the game image) and the brightness is dim, when it warms up everything looks sharp and great, however something is clicking/arcing (I can’t be 100% sure) as I can’t find where it’s coming from.

The other thing that is concerning me is that the large 30w resistor is getting really hot and there’s no static buildup when you power it on. I’m now thinking it’s the LOPT (flyback) that’s the issue.

Next step is measure the HV when I’ve got a spare moment. If that looks suspect, I’ll be replacing the LOPT

Normally if the 30W resistor gets really hot on the MTC 9000, it's due to the over current protection kicking in.
I could be wrong, but I always assumed if a fault is detected by the OCP it will shut down any High Voltage to protect the chassis / tube, but since you've got something displayed this may be something different in your case.
When the OCP triggers the most common culprits are a bad flyback and/or blown HOT, so these are probably still worth checking.

 

[qjuk]

Got the HV probe out on this today. It’s measuring 12kV which is obviously not right as I believe it should be 23kV.
Unfortunately because my HV probe has a slightly larger rounded tip (and is not changeable) it’s not so easy to get a good angle to measure under the anode cap on this. Slipping the probe under the cap lifts part of the insulation cup up and I was getting loads of crackling/arcing. I didn’t leave it there long to be honest. I’m sure the HV voltage should start at pretty much a tad under the correct level from cold, only creeping up a tiny bit when fully warm.

 

[gunblade]

yeah 23-24kv and it should be at that pretty quickly
you need to be braver with the ht probe, push right into the clip and hold solid, do not worry about the noise