What's new
It will be "ShuzhouhanshanTVfittings".

In Chinese, it will be "苏州寒山电视配件".
 
After viewing an earlier picture, the company is called "Shuzhou Hanshan TV"

Edit: Looks like @gitanes beat me to it. ;) :D
 
I tried one of these new replacement flyback transformers on a working MS-2931 chassis yesterday.

Before installing the new replacement flyback I tested the chassis with the original Nanao flyback first. Everything looked fine.

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Desoldering the original Nanao flyback went smoothly.

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And it came out without much fuss.

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New replacement flyback was soldered in. Note the three circles in red. These are actual pins on the orignal Nanao flyback and on the new replacement flyback they are stiff wire which you have to carefully position into place whilst aligning the pins of the flyback through the holes on the board.

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New replacement flyback installed. Note one of the stiff wires bottom right of the flyback.

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I connected everything back up on the chassis and carefully powered it on, ready to turn it off immediately if I heard any high pitched squeals or buzzing, but instead I was greeted with this disappointing image.

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I then remembered that I would need to adjust the focus pot on the new replacement flyback. I got out the mirror and was able to get the focus nice and sharp.

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Looking good, but I noticed the vertical and horizontal sizing was off. I reduced both vertical and horizontal sizing to zero via the OSD menu which produced this result :

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Vertical size is about spot on, but the horizontal size is still too wide and probably needs to be reduced by another 5% or so.

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I then tested B+ and it read a little low at 178.4V. I adjusted this up slightly to 180V but made no difference to the horizontal sizing. I then went into the "FACTORY" menu and played around with the vertical and horizontal limit size, but this didn't seem to make any difference. Perhaps I'm missing something... One other thing that I tried (and I STRONGLY recommend against trying this as it can kill your chassis) was adjusting the Horizontal Drive pot slightly, this also made no difference.

XSA4NmA.jpg


I then turned everything off, discharged the CRT, removed the chassis, desoldered the new replacement flyback and soldered back the original Nanao flyback and connected everything back up again. Using the same horizontal and vertical size settings, you can see the difference compared to the original Nanao flyback.

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I adjusted the vertical and horizontal settings back to their original settings for the original Nanao flyback.

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So to summarise, these new replacement flybacks do exist and do appear to work (I ran the chassis for about three hours with the new replacement flyback) without any squealing or buzzing, however they don't appear to be a 100% match due to the vertical and mainly horizontal size issue. Someone smarter than me might be able to suggest a change of value with a resistor or capacitor on the MS-2931 chassis to improve the horizontal sizing when used with the new replacement flyback. Perhaps this would be easier to solve with a MS-2930 chassis as I imagine you could change the value of the h-size pot to fix the issue.

I'd be interested to hear how other people go with their new replacement flybacks and if they run into the same issue I had.
 
@xga - That's one of the best tech write-ups I've seen in these forums. I didn't have to reread and take a guess at anything you said! Thank you!

Cool to see this working, and I hope we can solve the H-SIZE issue.
 
Outstanding @xga

While it might need some tweaking, this is excellent news for blast city owners. That picture doesn't look too bad, and a working chassis is much better than a dead one.
 
I'm still excited I bought my 4. The horizontal is probably just a resistor change
 
has anyone tried these new flybacks other than @xga. Grant on ao ordered some and I alerted him to this thread he's going to try to figure it out. Hes just super busy at the moment.
 
I got my MS-2931 back from the dead and working with that flyback, so yes, they work.
That said, the flyback is not as good as the original, the construction is more weak and looks "cheap".
Also, i had to turn the focus to the max on the flyback to get a good image.
The chassis also got a full recap so I'm still tweaking the geometry and colors.
My conclusion so far, the quality of the image is worst that when it was using the original flyback (kinda expected) but still, it's working good and the image quality is good just not as good as before.
 
Also, i had to turn the focus to the max on the flyback to get a good image.
@xga - Did you experience the same thing? Did you have to turn your focus pot all the way up for a decent image?
 
I was always told that turning the focus up all the way would destroy both the tube and the flybacks. Similar to having to crank the screen pot all the way.

Any truth to this?
 
Focus looks off on all the pics I see here. Corners are fuzzy. It's good to at least have some sort of replacement but it does not appear to be a perfect match yet.
 
Anyone know if the flybacks are the same between the MS2931 and the MS2933?
 
I've replaced a flyback today on a MS2931 blast city chassis and getting the same issue where H.Size is too large even at minimum width. Has anyone figured something out about this ? A way to fix it ?
 
it will need a cap value changed, i need a chassis to test a new flyback and then find the right cap- someone is sending one in soon so maybe will have an update
it will be a poly cap in the horizontal circuit and it will be rated at 200-250v and probably around 220nf- 330nf
 
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