Impress Monitor issue

[thchardcore]

Before I start, we need the classy KC smiley face that everyone would abuse after raunchy or homosexual jokes back on these forums. That is all.

I picked up a Capcom Impress a few months back, besides one cig burn, absolute beauty as far as lack of yellowing and overall cosmetic shape is concerned.

Some chassis/tube info: Toei chassis, Toshiba A68KJU96X-02

The picture tends to wobble though, almost like a grounding issue or something, but its like parts of the image wobble within the screen, the whole screen is not moving up and down, more of a twitching of some of the sprites, and no, its not the board .While I love how crisp the Toei's picture is, I have a refurbished Nanao MS9-29A with a Toshiba A68KJU96X tube that has some burn sitting next to me. I assume that I could just do a straight swap, if not I have another non burned Toshiba A68KJU96X tube, but the yoke was kind of messed with as far as seating and purity/convergence adjustments, so I'd rather just swap chassis. Question is, does the X-02 mean it might not work as it is different from the straight X? Also, do you think the problem with the Toei is related to the power supply? I know I can source an exact replacement but I'm looking at at least 60 USD to do so.

Anyway, any advice would be great.

Regards,

[Mellor]

You could try measuring the resistance at the yoke plug to see if they match. Both the horizontal and vertical deflection. I believe Grant says there is something else you need to test as well but I think it requires a special tool you prob won't have. Might be a starting block though.

[thegreathopper]

I did put a reply on yesterday but it has vanished.. never mind I will have another go.

I have done a full cap replacement on a Impress a while ago, it is a easy chassis to do a cap replacement as everything is well spaced out, it may be something a lot simpler that this, have you checked all connections from the neck board to the screen? there should be at least one earth connection to the screen from the neck board, sometimes they fall off in transit.

I have swapped a screen and a chassis on a Impress, the screen I replaced due to burn in came from a Sega Astro cab which I believe would of had a Nanao MS9 chassis. so if your chassis has had it you could put the Nanao chassis in the cab.

Also the Wei Ya 3129A chassis will work with this screen as I have tried this out so no it works fine.

I have a couple of these Toei chassis as I have a Impress and a neo 29 which both have these chassis fitted. luckily apart from burn in on a screen which I replaced and was kindly supplied and delivered by Mr Megalo I am very pleased with these monitors.

[mukurop]

Those chassis was made by HITACHI, they drive Toshiba tube on capcom Impress and Hitachi tube in Super Neo 29 cab, the chassis are the same but the neck board are not, basically it is possible swap the chassis but all Toshiba tubes must comes with original neck board from Capcom impress.
Toshiba tube on new astro City and all Sega cabs must be drived by NANAO chassis do not try to use the Hitachi one or you got it damaged due to the different impedence of the tube. On my advice the best way is replace the monitor and chassis.

[grantspain]

Those chassis was made by HITACHI, they drive Toshiba tube on capcom Impress and Hitachi tube in Super Neo 29 cab, the chassis are the same but the neck board sre not, basically it is possible swap the chassis but all Toshiba tubes must comes with original neck board from Capcom impress.
Toshiba tube on new astro City and all Sega cabs must be drived by NANAO chassis do not try to use the Hitachi one or you got it damaged due to the different impedence of the tube. On my advice the best way is replace the monitor and chassis.

it all comes down to the yoke specifactions,neck pin layout and heater voltage.
nanao ms8 series,ms9 series,sanwa pm1745,sanwa 29es31s,wei ya 2931,rodotron 666a,neotec 2702 all are interchangable as they run only almost identical yoke specs-if you had a standard multimeter you can read the horizontal and vertical resistance of the yoke and also you need an inductance meter to read the horizontal and vertical inductance,also you need totake into account the power voltage required by the chassis.earlier chassis will need an isolation transformer and 120 vac-later chassis do not require any such thing.
i have never seen a hitachi chassis so i cannot comment on those

[thegreathopper]

Those chassis was made by HITACHI, they drive Toshiba tube on capcom Impress and Hitachi tube in Super Neo 29 cab, the chassis are the same but the neck board sre not, basically it is possible swap the chassis but all Toshiba tubes must comes with original neck board from Capcom impress.
Toshiba tube on new astro City and all Sega cabs must be drived by NANAO chassis do not try to use the Hitachi one or you got it damaged due to the different impedence of the tube. On my advice the best way is replace the monitor and chassis.

I swapped out the Hitachi tube on my Neo 29 a couple of years ago with a Toshiba from a Sega cab and apart from the picture being much better now it runs fine.
What are the differences on the neck board as they are the same pin layout.

[mukurop]

As you can see the two neckboards are different, both neckboards have the same chassis (Hitachi GML) but the one on the left comes from Super Neo 29 and attached to Hitachi GMK-29FSN tube(same neckboard with blue knobs it is also used in Astro city with nanao chassis and Toshiba A68KJU96X Tube or Hitachi GMK-29FSN) the one on the right comes from capcom Impress and its for Toshiba A68KJU96X-02 tube Only.
Hitachi GML chassis have gray plastic base on Capcom Impress and Black Plastic base on Super Neo 29 they are the same eccept for the neck board.
Basically it is possible swap the chassis from Super neo 29 to Astro City-New Astro city but capcom impress wich have Toshiba A68KJU96X-02 need its neck board.

[grantspain]

i can't see a difference in those neck cards,both standard 10 pin 29" neck pinout-only minor thing is the left crt socket has a cut out

[mukurop]

and yes those neck boards are very similar but designed for a different horizontal and vertical resistance and inductance of the yoke, if you take a close look, you can see that the socked not are exsactly the same the one with blue control knobs do not fit well on Toshiba A68KJU96X-02 tube! I want advice because I have damaged one chassis to try swapping directly without adapt the right neck board. I have two capcom Impress, one New Astro, one Super Neo 29 and one Net City cab I have managed to swap monitors chassis and repair them lot of times, please trust me. I stay in Italy but have lot of friends in japan and they are tecnician who help me all the times for repair those staff. In attach some cabs in action in my room. Sorry for my bad English...I will do my best to make me clear.

[grantspain]

the neck board should have no affect whatsoever to the yoke/deflection/frequency,the only thing that could affect is the heater voltage-which would be a resistor modification
the crt socket are fractionally different but they should fit,at worst you would need to file out a bit of the plastic case

for anyone wanting to swap chassis just get a lcr inductance meter and a standard multimeter,from the readings you will be able to match chassis safely

be interesting for someone to get this toei chassis yoke readings

[thchardcore]

What could be causing the slight "twitching I mentioned" it seems to wobble more when I **** with the vert size/hold. Bad Pots possibly?

[grantspain]

maybe a leaky b+ filter cap or another cap,ground issues normally give interference type issues