Looking to do a chassis swap (ms9 on A68KTB189X) and have questions.

[Lemony Vengeance]

Hey all, I would like to put an MS9 on a Toshiba a68KTB189X tube and I have questions.

Here’s the yoke measurements:

The frame of the monitor says it was pared with a Toshiba D29CR55 chassis.

There were some connector modification I needed to make to get the connectors to work with the chassis, connected everything up and got this:

Looking over the yoke measurement thread, I’m thinking the yoke may not be compatible with this chassis. Has anyone been able to make this swap? Additionally, if this is compatible, are there any resistors that should be added on the yoke?

 

[nem]

Is that with the width pot maxed? Did you also adjust the horizontal size limit pot?

 

[Lemony Vengeance]

Is that with the width pot maxed? Did you also adjust the horizontal size limit pot?

Width pot is maxed on the remote board (brand new pxlmod remoteboard) size limit on the chassis hasn’t been touched

 

[nem]

Adjust the size limit. It might fill out.

You can also try the wide jumper if it's set to narrow.

 

[phokkun]

Pardon the bleary image but go over HS.LIM like Nem said.

Here's an A68KTB (Toshiba in this case like yours) pulled from a DDR running a MS9 chassis. All I had to do was make an adapter for the yoke.

 

[Lemony Vengeance]

So, update..

The horizontal size pot on any remoteboard I use does not work neither does the HS.LIM on the chassis itself

 

[Plymelk]

How did you splice the new connectors from the Toshiba D29CR55 yoke to mate to the Nanao MS-9? Did you remove the old wires completely and solder new wires to the headers of the yoke or did you snip the existing wires and crimp new terminals to match the MS-9 connector? Sometimes the vertical section can have three headers with different inductance readings depending on which two were used.

The image looks like yoke incompatibility but we know that the Ms-9 and Toshiba yoke are compatible. I assume this chassis is known working?

 

[Lemony Vengeance]

Admittedly I remember it having horizontal adjustment issues in my e29, but didn’t pay it much mind there.. I have a few MS9 chassis I can test with this tube, but I’d rather not pull another just to discover the same issue

 

[nem]

So, update..

The horizontal size pot on any remoteboard I use does not work neither does the HS.LIM on the chassis itself

That explains it. Check Q508.

 

[Lemony Vengeance]

That explains it. Check Q508.

Q508 tests good. Voltage drop between base and collector is .6v, same with B->emitter. There is no continuity when tested backwards.

 

[Lemony Vengeance]

How did you splice the new connectors from the Toshiba D29CR55 yoke to mate to the Nanao MS-9?

Snipped and crimped

The image looks like yoke incompatibility but we know that the Ms-9 and Toshiba yoke are compatible. I assume this chassis is known working?

In my e29, yes.

I also checked b+ voltage and it’s at 77.55 VAC.. slightly above the suggested 76 VAC that is suggested, but still in the right neighborhood.

 

[9999 Damage]

Watching this thread. I've got an Astro with a D29CR55 and Toshiba tube, and I have a spare MS9 sitting around.

 

[Lemony Vengeance]

Here's an A68KTB (Toshiba in this case like yours) pulled from a DDR

I pulled this tube from a Guitar freaks I converted to LCD. The yoke measurements were slightly off from what had been shared in the yoke thread, but it was still very close.

 

[nem]

Is this a recapped chassis?

Anyway, fault is 100% on the chassis. Try replacing the caps near the geometry adjustment pots on the chassis.

 

[IPD]

Do the TRAP and SPC15 pots work?

 

[Lemony Vengeance]

Is this a recapped chassis?

Anyway, fault is 100% on the chassis. Try replacing the caps near the geometry adjustment pots on the chassis.

no not recapped yet.. dang it. hahaha.

 

[Lemony Vengeance]

That explains it. Check Q508.

so, following up on this FINALLY!

Turns out Nem was on the right track. I was speaking with @cruzlink2 about this issue since I had recapped it and it persisted. He suggested I follow his advice here:
https://x.com/Cruzlink2/status/1602763213170524160?t=ZIWT-tPauR52a3iodHsoEg&s=19

and sure enough, that was the issue. Pulling the solder off the contacts, scraping the mask off the traces and linking the pins with the traces a bit better resolved the issue. it's looking good now



believe it or not, it looks much better in person. now that I know this chassis was the cause of the issue, I'm going to put my spare MS9 on the TOSHIBA tube/yoke I mentioned above. given that it's the same model chassis, it'll likely work great. I'll update when I get the other chassis back from repair.