CurtPalme.com Home Theater Forum

[speedyandre]

Hi

After struggling with powerup failures my 1292 is working, but the blue tube is dim compared to the others.
I can look in it when displaying testpaterns without lasering my eyes
In the setup the gains for blue are pretty high so I think the last owner also had this problem and didn't know how to correct it.
The picture doesn't show correct whites, it tends to be beige.
Also my htpc didn't clone like it should so I'm missing a part of the screen and I didn't setup the 1292 for pc use yet



André

[Curt Palme]

It's most likely a bad tube. THis tends to be common with Sony 8 and 9" tubes. I'd post for a new blue tube.

[Curt Palme]

It's most likely a bad tube. THis tends to be common with Sony 8 and 9" tubes. I'd post for a new blue tube.

[speedyandre]

Is was looking for some good news, e.g. swap this and that board
Couldn't it be the HV block, I can try to exchange some cables but I'm affraid it won't help ....

André

[Curt Palme]

No, it's not hte HV. The cables aren't long enough to switch between tubes on the 1292, so unless you want to send me the video driver boards to test in a set here, you're sort of stuck..

[Curt Palme]

No, it's not hte HV. The cables aren't long enough to switch between tubes on the 1292, so unless you want to send me the video driver boards to test in a set here, you're sort of stuck..

[speedyandre]

I've been swapping boards for a while to get it up and running, I don't think that a driver board is bad.
The neckboard of the blue tube has been swapped, it gave me no better picture.
What I've tried is swapping the neckboard, the DC and the E board and also some power boards (PA and EA).
Can the blue tube give a dim picture while all voltages on the tube are the same as on the other tubes?

André

[Curt Palme]

Yes, it's the blue tube that is bad..

[Curt Palme]

Yes, it's the blue tube that is bad..

[speedyandre]

I guess I'd better listen to my cd's then looking and listening to this hoovercraft

André

[r.bauer]

So I took the Sencore CR7000 Analyzer & Restorer over to André and tested his 2500hr blue SONY 09MX tube: It was bad, very bad! No emission at all on the scale while the red tube had emission through the roof.

So I applied a couple of Re-activate cycles of approx 5 seconds each: nothing. Three 2 sec. LOW-restore attempts and one 2 sec NORMAL-restore attempt and nothing changed. Still no emission at all. It would only go into very low emission at a bias setting of -20V instead of the regular -132V. We powered up the projector after these attempts and blue was still very dim, even with bias and gain set at max. Again, no improvement.

Until now I have fixed only MEC tubes, although with different problems. They all had Bad G2 settings and clear raster and retrace lines. All these tubes were fixed with one or two short 3-sec cycles of LOW-restore. Only once I had to apply a 5 sec cycle of NORMAL-restore. And every time there was improvement after each cycle. Sometimes more cycles were required to completely fix the tube

So I really pushed it with this SONY tube, but the fact that nothing has changed at all makes it clear that this tube does not have any emission and the Cathode is not the problem, as with earlier successful MEC attempts. I have already burned off enough cathode material in this gun.

Any other suggestions as why this tube does not have enough emission? I can only think of a less then perfect vacuum in the tube, and that cannot be fixed. Any other suggestions, and possibly fixes are welcome.

Comment: The 09MX tube was not listed in the Sencore tube listing, so I used the P19 MEC parameters instead, as the tubes are used in similar circuits.

About the CR7000:
- Re-activate is nothing more than a 50% increase in filament voltage, this can sometimes burn off debri.
- Restore has four settings: low 20mA 2sec, normal 80mA 2*2 sec, high 100mA 3*2sec and extended100mA 15 sec. This I have never had to go higher than normal
- Rejuvenate: Never had to use this one.
The CR7000 has very low restore settings, as these are required for CRT projection tubes. High settings can easily destroy a CRT projection tube.

Last minute thought:
The 1292 uses the push-pull method where both the cathode AND the G1 are fed with a complementary video signal to achieve the required voltage swing of 70 to 80 volts. Could it be that the G1 is the problem? I will think about this tomorrow.

[Ile]

I have bare 09MX or 09MI blue tube (they are similar) from BG1200. Tube is about 7-8 or something, so don't know how well it will pair with others...

[speedyandre]

I maybe can use another similar tube (if it is pin compatible) when this is the end of the story.
Can you make a picture of the wear, I hope it is full sized and equal.

André

[speedyandre]

Any ideas about this tube or the G1 as Reinier thought?
The last days I've put a full white on the blue tube for hours to get it back alive but it doesn't work so far

André

[Ile]

G1 problem should be in mobo or in neck board cable, because you swapped neck board already. Pretty unlikely...

Maybe bad vacuum in tube can cause this. Sony tubes have glued front glass and that white goo goes soft when it's in contact with glycol.

[speedyandre]

I'll get this one up
Since I found some 09MX tubes for sale I want to be more confident that they are compatible with the 09MFX3 tubes in my Sony 1292.
Sony is known for using the same pinout on different tubes, can someone tell if some pins on tubes for Barco 1200 are cut?
Maybe a close-up pic can show some more, especially how some leads are connected inside the tube

André

[speedyandre]

The labels in my 1292 say 09MFX3.
I hope someone knows if the 09MX (if no pins are cut) is really (pin)compatible
The neckboard is a quite complicated sandwich of boards, so a mod to change the pins is hard to do ....

André