Taito Egret II with Tube MS9-29S and Chasis 29A (from NAC) Green Boot Problem!

[Dhampird]

Hello, some months ago i get another Egret2, i know the seller changed the tube and chassis (swaped from a NAC) in the Egret2, then i have a MS9-29S tube (A68KJU96X) and MS9 29A chassis.
Well, after turn on the candy i can see how the screen shows the image with a green tint colour for 1-2 secs almost, after that the colours are displayed ok, no more green tint colour on screen. I thought this happen because the 29A chassis dont have autodegauss (tell that i noticed 29A is conected to the Egret2 video jamma conector without modifications, i mean that the jumper cable, that joins degauss circuit in Egret2 jamma conector is present like if a 29T was conected, if i´m right that jumper cable on conector should be released using a 29A chasis to add a manual switch instead that jumper cable)
Then, i get a 29T chassis from Japan, because i´ll want the autodegauss and no the 29A, well, at first 29T test i noticed that the Green tint still appeared on screen and this time not for 1-2 seconds, appear all the time, i had to move the Gain Green pot on Remote to adjust the colour to avoid the Green Tint on screen, after do that Green Tint appear on screen only for 1-2 secs after boot.
I tried also the 29T from the another Egret2 i have, same results, it seems Green tint appear at first Turn ON and need change the Green Gain pot on remote.
After those tests i reccapped and resoldered all the 29T and 29A, also i cleaned the tube to try see if something wrong in yoke, no changes, remains the Green boot screen after Turn on.
Also i recapped all the PSU
I thought that maybe that problem is normal because for some reason the tube turns on earlier and shows that green tint with the game intro displayed image that in anothers tubes should be displayed on black, seems like the tube turns on earlier than another tubes and happen that? All tests are done with an Atomiswave Base conected to jamma, in the another Egret2 tube (MS9 29T) this not happen, i mean the Green Tint colour on boot for 1-2 secs.
I remember that with 29A the Green Boot tint happen only for a 1-2 secs and after all colours displayed ok, i suppose this happen because the Green tint pot on chasis is adjusted to avoid the Green saturation always, like i did with 29T to avoid the Green tint saturation, but then, this tell me that the tube displays always a Green tint (not only in boot after turn on)? Why happen this? Could be related with something in tube Yoke?, a voltage problem?
Any help is welcome.

[buttersoft]

You can see problems with coloured screens to do with short-circuits within an electron gun, if i have that right. Your problem doesn't sound quite like this, but could be examined with a tube tester/rejuvenator.

[Dhampird]

Mmmm...please let me know whick kind of tester i could use and how begin to make tests, i read about a "Blue Ring Tester" somewhere but i dont know if that tester can be usefull in this case. I´m just reading about the devices  tube tester/rejuvenator , which model could use in this case with nanao ms9?
Thanks a lot for reply.

[buttersoft]

Lets clear up some terms. The monitor is composed of the glass tube, and the chassis (electronics/PCB). If you've changed the tube to a fully compatible tube with the same pinouts and voltages (see below) but are using the same chassis, and the green problem is still there at all, even briefly, it's far more likely to be a fault with the green transistor on the neckboard, or something in the green video signal path like a half-broken trimpot.

If the problem only happens with one tube, it might be the tube. This is what I thought you said above.

I don't know enough about specific rejuvenator models to recommend one, sorry. Most of them came with a book of tube numbers which would tell you the pinout and voltages for your tube, and then which socket adapter to use for the rejuvenation. Most models would get away with 4 or 5 socket adapters, as tubes weren't so different from one another. You could try finding the pinout and voltages for your tube, including the bias voltages, and working backwards. Pull the model number off the tube itself and try google. I'm not sure, but maybe you could use that info to find a compatible rejuvenator.  I'd guess most of them would work, but i don't know that for sure. This site might also help - http://tubular.atomized.org/

Rejuvenation or removal of shorts is always a gamble - it might work, or it might appear to be going ok but then kill the tube without warning. Using the tester functions to identify problems doesn't hurt anything though. It'll be easier and maybe cheaper to get another tube though, be aware.

[Dhampird]

Hello, it seems problem be related only with the tube itself inside that Egret2 , i mean that i tested 3 different chassis with that tube, a 29A and 2 differents 29T chassis, those chassis dont show none problem in another different tube i have here (MS9-29T), then i discard problems on pots or transistors with those chassis, seems problem happen only with the MS9-29S tube.
Now i have a 29T attached to the MS9-29S tube, I adjusted better flyback, Green cut Off (chassis), and Green Gain (remote) but the boot Green Screens always remains when machine turns on (also tell that i had to use a low brightness config to get perfect blacks, it seems the Green effect still working on background changing brightness or blacks if brightness is high?)
I dont know for sure if this is normal because for some reason (voltage problem?) , maybe that 29S tube screen after turn on, lights faster than it should? and maybe if will turn on with 1 second delay the screen always will display perfect colours on it?, i mean with this that maybe all tubes do that green boot but in this case for some reason image on the tube is displayed more faster and there is no time to green boot dissapear from screen?, i dont know.
Any voltage problem could be a reason?
Here a video with the green problem itself on boot:

Thanks a lot for rejuvenator info, i´ll search more about it.

[grantspain]

if it was a gun short it would be there all the time
if it were a chassis signal related issue it would be almost impossible for more than one chassis to show the same fault-improbable I should say
only leaves game board
have you tried a different video source?

[Dhampird]

Hello grantspain about:

if it was a gun short it would be there all the time

its there all the time but i touched Green Cut Off (chassis) and Green Gain(remote) to dont see the Green tint all the time, is the only way to avoid see Green Screen all the time, anyways even touching that pots the boot remain in Green like video show. If i remember well Green Cut Off value should be near to 0 ohm and same for Gain Green, i could measure the value.

if it were a chassis signal related issue it would be almost impossible for more than one chassis to show the same fault-improbable I should say

i think the same, no chassis problem, even i tested those without recapping and later fully recapped and all resoldered and same results.

only leaves game board,have you tried a different video source?

i remember test a j-pac with groovymame and pc and same happened at boot, after that i changed 29A chassis por a 29T and i saw how the green screen was present on screen all the time, the "solution" was touch Green Cut Off pot and Green Gain to avoid the green on screen all the time, but seems the problem remains there, then should i think in a gun short?