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MS2934 Flyback replacement

LazerFlux

LazerFlux

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So I've got an MS2934 that appears to have a bad flyback.
board's recapped and continuity tested, transistors appear fine. 180V @31KHz pin on the flyback is not outputting.
The labels on both flybacks I have as samples are long since worn.

The service manual I've been able to locate does not a part number for the flyback, so I'm not 100% on which flyback it actually is.

Does anyone know what flyback is in this? is it the same one as the 2931/2932?
Or does anyone have a more complete service manual, with a BOM?

I'm looking at this as a possible replacement, assuming the above is true. https://www.ebay.com/itm/223543070073
I know that these are not as high quality as the originals, however finding a replacement flyback that's NOS appears to be impossible, or I'd have to buy a whole chassis for quite a bit of cash.

Thank you for any knowledge imparted.
 
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I don't have an exact answer for you since I don't have a 2934 on hand, but if you do find that the MS2931 flyback is the same, I have 3 non-working chassis here all with different issues and I'd be willing to let one go at cost.
 
trashedcabs said:
I don't have an exact answer for you since I don't have a 2934 on hand, but if you do find that the MS2931 flyback is the same, I have 3 non-working chassis here all with different issues and I'd be willing to let one go at cost.
Click to expand...
Thank you! I'll let you know. Hopefully that is indeed the case
 
trashedcabs said:
I don't have an exact answer for you since I don't have a 2934 on hand, but if you do find that the MS2931 flyback is the same, I have 3 non-working chassis here all with different issues and I'd be willing to let one go at cost.
Click to expand...
I've asked an expert and received a tentative answer that the MSU1FUS11 from the MS2930 and MS2931 should be compatible. Up for an experiment?
 
I bought a replacement MSU1FUS11 from Tekno-Service, however the footprint appears to be different. The two upper/side pins which would normally fit are lopped off, and there are 3 wires instead.

@trashedcabs Do you have the model # from your flyback by any chance, or are you able to compare it to the ones shown in this image? (Original MS2934 flyback on the left, replacement on the right)
PXL_20250805_181624084.jpg
 
trashedcabs said:
Mine is also MSU1FUS11

FWIW this is pretty common for third-party flys. They use a generic plastic shell and the footprint is usually close enough but it's typical to have to bend things around to make it fit.

There's a good install log here: https://www.arcade-projects.com/threads/nanao-ms-2931.9238/page-7#post-154801
Click to expand...
Thank you! I'll have to check some schematics to ensure I'll be using the correct pins/wires, as there are only two extra pins on the MS2934. I'll update this thread on progress/adjustments.
 
In my experience on an MS2931, you need to use the "HV Adj" pot on the chassis (near the flyback) to fix the image size issue in that install thread.
That said, I can't confirm if it's the same on an MS2934, or if the flyback is even compatible.
 
I have one of his Sanwa E31S flys and it immediately puts my chassis into shutdown.

To be fair with HR Diemen flys being low availability and Chinese repros being the only option, at this point I've given up and am dealing with using used flys. I've multiple from APAR die within hours and the Teknoservice ones are massively overpriced and have issues.
 
The ones on APAR look to be of the same or similar manufacture as TKS, based on visual features. However, if it's a perfect drop-in replacement I'm all ears.

As far as used chassis', go, let me know if anyone has a working MS2934 around that isn't 600+USD (like the one being sold by TKS right now). From what I can tell, while the 2931 and 2934 flybacks may be compatible, they have a different footprint and pin layout. In the meantime, I'll see if I can make this TKS flyback work out okay.
 
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