Nanao ms9 29su

[dracotom]

Hello all,
I come ask a little help if possible.
So, i have a Nanao MS9 chassis and my problem come from the CRT PCB i guess.
when i turn on my monitor i can ear a noise inside the tube and look like on my crt PCB.
If i let it turn some minutes, usually my transistor Q506 die or i have a vertical line on the screen. I searched the problem with all  horizontal component but with any succes...
I serarched too in the power supply area but nothing look like bad.
If anybody have an idea i'm of course interested
I find a video on youtube, the guy have exactly the same prob as me, if that can help you...
https://youtu.be/aO5ETnzR5nk?t=274
In advznce thank you!

[grantspain]

actually you told us why you have this issue in the video-perhaps you did not realise

the original tube/chassis combo was most likely ms2930,2931,2932 or 2934-these are all 0.198mh hl chassis, the ms9-29 is 0.300mh hl

this is why you have the very wide picture and the nasty noise-they are not compatible

[dracotom]

Hello, thanks for your reply!
if i unserstand good it's my tube who is not compatible with the chassis?
i don't have the same tube as the one in the video.
but you right, the tube is not the original for this chassis, it is a Naomi tube with a 29E31S chassis, do you think the problem come from here too?
I though with the same size and plugs was enough to make it work good, i was wrong.
i can have the original tube so i'll make a test.
Do you have a topic with the differents tubes/chassis compatibles?
I read some posts of you, you seem to really good know this MS9 chassis, do you know if it's possible to plug a vga cable on it?
Thanks a lot for your advices, i'll test it quick!

[grantspain]

you would need to read the inductance of the windings of each vertical and horizontal to prove it

es31 were never used on Toshiba tubes, they were used on a tube made by shanghai novel-this tube is 0.300mh but there was a difference on the pinout of the neck-something to do with an extra ground pin I think

[princess prin prin]

The Sanwa 29E31S manual (ver. 1.2) reports the Toshiba A68KSM696X as one of the possible tubes besides the Chinese ones.

[dracotom]

Hello,
i would like to thanks you  grantspain,
you was right, it was my non compatible tube the source of the problem.
i swapped with the original one and it works perfectly fine!
Thanks to share your experience
And do you know if i can plug this chassis with a vga cable?
Thanks again for your help!!

[grantspain]

the ms9-29 is a manual switching 15k/25k chassis(auto switching if ms9-29A)
to display 31khz vga signal you would need a converter of some kind, I do not have any experience with doing this but I have seen you can achieve this with soft 15k or an arcade vga card-someone else will be able to answer this question