CurtPalme.com Home Theater Forum

[Apfelmousse]

Hi,

I made some experiments prior to hooking it up to the ceiling. In particular I was testing size and centering controls to find out the minimum distance between lenses and screen. With the standard lenses this seems to be around 2,20 meters, focus on the lenses near to the full CW position.

At some point I noticed a strange distortion in the lower left corner. It seems to originate from the blue horizontal circuits, as it depends on blue horizontal size setting. It appears when this setting it is below 100. I added some pics to illustrate. It influences red and to a much lesser extent, green. When blue size setting is above 100 the corner looks perfectly normal.

Anyone else noticed this?

regards
Martin

BTW: I ordered the Dallas chip - directly from Maxim. Delivery will probably take some weeks.

[Curt Palme]

That is usually due to too much convergence or other parameter applied. My first bit of advice though:

Check the Dallas chip date, and if it is pre-2005, DO NOT use the machine. It's a 4 digit date code on the chip, 9912, would mean 1999, 12th week of manufacture.

0542 would mean 2005, the 42 week of manufacture. You do not want to kill all 3 tubes with a spot burn due to an old Dallas chip, trust me!

if it is a later chip, then I'd reset all of the convergence zones of the blue to 128, the default, do a really careful setup using all the other controls, and then use the zone convergence minimally.

[Curt Palme]

That is usually due to too much convergence or other parameter applied. My first bit of advice though:

Check the Dallas chip date, and if it is pre-2005, DO NOT use the machine. It's a 4 digit date code on the chip, 9912, would mean 1999, 12th week of manufacture.

0542 would mean 2005, the 42 week of manufacture. You do not want to kill all 3 tubes with a spot burn due to an old Dallas chip, trust me!

if it is a later chip, then I'd reset all of the convergence zones of the blue to 128, the default, do a really careful setup using all the other controls, and then use the zone convergence minimally.

[Apfelmousse]

Curt,

thanks for the advice. Indeed, I made a first quick setup with the blue lens a little bit misaligned, and had some trouble doing convergence on the left side of the screen.

Promised, I'll do that properly once its up on the ceiling. My main purpose of these tests was to find out the minimum distance to my screen with the maximum raster on the tubes. The lens-program gives a minimum of 2,70 metres, but I can get much closer.

Promised, too, I'll not use the set anymore before the Dallas chip arrives. Mine is dated 98...

cheers
Martin

[Curt Palme]

Yup, that's playing with fire!

[Curt Palme]

Yup, that's playing with fire!

[Apfelmousse]

BTW, I left the set in standby the last days. That did NOT increase the hours counter. Since I have 1300 hours on the total and 70+ on the tubes I wonder how that came.

Can it be the Dallas lost some of its memory once and now re-functions?

As I said in another thread, the tubes look new and the set is very clean inside. It even has a "new" smell when running.

cheers
Martin

[Apfelmousse]

[Curt Palme]

No, you need to initlaize them, otherwise the '31' error code will come up when you try to power up. Let's see if someone else can post how to initialize it (I am running out for dinner), otherwise I'll advise tomorrow.

[Curt Palme]

No, you need to initlaize them, otherwise the '31' error code will come up when you try to power up. Let's see if someone else can post how to initialize it (I am running out for dinner), otherwise I'll advise tomorrow.

[barclay66]

Hi,

You could send them to me together with the old chip as I have the equipment for reading/programming them. Send a PM if You‘re interested.

Regards,
barclay66

[jbltecnicspro]

Not to rehash this - but why oh why did Sony use the Dallas chip instead of an EEPROM? Is there some technical advantage they offer?

[Curt Palme]

Electrohome did it too in the ECPs

[Curt Palme]

Electrohome did it too in the ECPs

[AnalogRocks]

[AnalogRocks]

[Curt Palme]

If you can find one, sure!

[Curt Palme]

If you can find one, sure!

[jbltecnicspro]

[Curt Palme]

Sure, but:
1) I don't think Sony expected people to still have them 20+ years after they were made.
2) Sony couldn't predict (or maybe they didn't test) the fact that a dead Dallas chip could nuke tubes.
3) I'm sure in CRT projector training sessions that they may have covered the Dallas chip changing. Problem is, 10 years and 2-3 owners and techs later, do you think any of that info got passed on? Nope! AV people in general aren't interested in fixing stuff, hell, I've bought many 9" projectors from end users whose AV company told them that they were not HD compatible. By the time they found out they were, they'd already spent $10-20K on a 'HD compatible' digital. Go figure.

[Curt Palme]

Sure, but:
1) I don't think Sony expected people to still have them 20+ years after they were made.
2) Sony couldn't predict (or maybe they didn't test) the fact that a dead Dallas chip could nuke tubes.
3) I'm sure in CRT projector training sessions that they may have covered the Dallas chip changing. Problem is, 10 years and 2-3 owners and techs later, do you think any of that info got passed on? Nope! AV people in general aren't interested in fixing stuff, hell, I've bought many 9" projectors from end users whose AV company told them that they were not HD compatible. By the time they found out they were, they'd already spent $10-20K on a 'HD compatible' digital. Go figure.

[CIR Engineering]

[Apfelmousse]

Hi Guys,

coming back to my initial topic: convergence issue.

I did some study of the "theory of operation" manual here on Curt's site. There'a a DA board generating basic waveforms that are fed into the DB board that adds the zone control. Bottem left seems to be zone #7. But this is for keystone and pincushion only...

What I do not understand: where is the convergence done? And I can do these settings for each colour - but there's only one DA board. I would have expected some circuitry for each colour.

Can anybody enlighten me?

cheers
Martin

BTW: I got a rather modern programmer (a BeeProg+) from my lab today. It supports tens of thousands of chips, in particular all Dallas types. The one's I received from Maxim are 70ns type, which should work in place of a 120ns chip if the circuitry has been properly designed... we'll see

[CIR Engineering]

Also, why is your vertical amplitude set to MIN? I don't think it would cause your issues because I modify the vertical deflection board for running the G90 with 3D so that it can squish the vertical much more, but I think Curt is right and you are pushing a bunch of different values at the same time. If you go too far the projector will shut down and you will be unable to access the video memory again without the projector shutting down. Then you will either have to apply no signal and reset to factory defaults or go into "expert mode" memory managment and delete the memory for the resolution you are working with and start from scratch.

As far as horizontal goes, you can set the magnetics on the horizontal deflection board once you have the projector in its proper mounting location. If you take the decorative cover off the G90 you'll notice three holes in the cover of the horizontal deflection board. You do not even need to open the case!

Set the horizontal amplitude to neutral 128 on all there tubes in the service menu.

Align the three tubes mechanically, such that their outer edges are equidistant from the screen edges on the horizontal while the image is centered in the tube face horizontally.

Put up a cross hatch pattern from an external source.

Use an Allen wrench that fits the magnets behind the three holes and adjust this such that all thee tubes have the correct width at 128 +/-5 for the horizontal amplitude.

You may need to iterate a little bit because of the magnetic change due to the Allen wrench.

This will mitigate any need to push the horizontal amplitude much in either direction.

craigr

[CIR Engineering]

[Apfelmousse]

[Apfelmousse]