CurtPalme.com Home Theater Forum

[runco940]

Hello All,

I had a question regarding an upgrade. I currently have a Runco 940 with about 1100 hours with mint R,G,B tubes and no tube wear. I can squeeze out 720p onto a 120" 16X9 screen with 99% light control. I am happy for the most part with its performance but an opportunity has come about locally for a used Sony G90.

Is this worth upgrading to? If so what questions should I have answered that are to specific to the G90. I know the obvious regarding chassis hours and tube conditions. I've been reading over this forum for the past few days regarding the G90 it seems apparent that these units are reliable but are not without their issues. The two things I keep reading about are defective YA boards and something called a Dallas Chip.

According to what I've read, both seem very difficult issues to resolve considering the availability of parts. Is there any insight anyone might have to identify which units (batch/lots) seem to be unaffected by these issues? I would appreciate any help or opinions on the matter. All things considered, is this a worthy upgrade? Thanks!

[gjaky]

The G90 is a really big step up from a runco 940. The question is how much do you want to spend on it, sony set the brightnes/contrast settings way too high by default, so an untouched G90 can have wear on the tubes with as less as 1000 hours, and then comes the chance-factor, if the old wear is even and big enough to stay within with your new setup, or you have to buy one or more new tubes which are actually more expensive than the projector itself.

[Curt Palme]

What gjaky said all makes sense.

I've been selling mint tube G90s for $3500 (usually with a new green installed), and have two coming up with all brand new tubes for $4500. They've been flying out the door, I've sold about 15 this year, with at least 5 more coming in before the end of the year.

The only part hard to get is the Ya board with the chip that's unavailable. I've scrapped enough G90s now that I have a full stock of 2-3 sets of boards and other parts for the G90, so getting replacement parts isn't as bad as it used to be 3-4 years ago. Even the Ya board can be had at this point. I just sold my spare, but will have another working one within the week.

Finding a mint G90 is the hard part. All but one of the 15 I've had in this year had significant wear, requiring the change of at least the green tube. One other one could have been used as-is, but since the green showed a bit of wear, I always change them out so the sets are perfect.

[Curt Palme]

What gjaky said all makes sense.

I've been selling mint tube G90s for $3500 (usually with a new green installed), and have two coming up with all brand new tubes for $4500. They've been flying out the door, I've sold about 15 this year, with at least 5 more coming in before the end of the year.

The only part hard to get is the Ya board with the chip that's unavailable. I've scrapped enough G90s now that I have a full stock of 2-3 sets of boards and other parts for the G90, so getting replacement parts isn't as bad as it used to be 3-4 years ago. Even the Ya board can be had at this point. I just sold my spare, but will have another working one within the week.

Finding a mint G90 is the hard part. All but one of the 15 I've had in this year had significant wear, requiring the change of at least the green tube. One other one could have been used as-is, but since the green showed a bit of wear, I always change them out so the sets are perfect.

[runco940]

[Spanky Ham]

A flashlight is ok, but the only real way to check the tube condition is take the lenses off. It takes 10 minutes.

[gjaky]

[draganm]

[HaydnG90]

I know that G90 if its the one I think you're referring to. I've met the owner and seen it in action. It was setup by john Gannon a few years ago. Not sure how many hours are on the tubes but I think its safe to assume there will be wear on the green, unless it was recently retubed. The wear if it exists may be hard to hide as the projected image seemed quite small vs the distance to the screen. I would recommend you take off the green lens and take a look as the price is pretty high if a new green is required.

[Curt Palme]

Tube wear has any number of factors attached to it. Proper throw distance, brightness and contrast settings, and G2/gain settings all affect tube wear. I've seen worn tubes at 1000 hours, I've seen perfect ones at 9000. If you can't physically check the tubes out, either lowball like crazy, demand flash and non flash pix of the tube faces, or simply buy a set where you know the Dallas chip has been replaced, and tubes are new.

If you don't change the Dallas chip at this point, you risk spot burning the tubes if it fails while the set is powered up. I've seen this a few times now.

[Curt Palme]

Tube wear has any number of factors attached to it. Proper throw distance, brightness and contrast settings, and G2/gain settings all affect tube wear. I've seen worn tubes at 1000 hours, I've seen perfect ones at 9000. If you can't physically check the tubes out, either lowball like crazy, demand flash and non flash pix of the tube faces, or simply buy a set where you know the Dallas chip has been replaced, and tubes are new.

If you don't change the Dallas chip at this point, you risk spot burning the tubes if it fails while the set is powered up. I've seen this a few times now.

[runco940]

Thanks for all the response they've been very helpful.