[Tim Smith]

I took my sony 1270 apart today so that I could adjust the G2 level according to the 1271 service manual. The manual lists various pins on the CFB-5 connector that you need to measure with a digital voltmeter.


Well, I was pretty shocked to find that the board that is supposed to have the CFB-5 connector only has a 2 pin connector on the 1270.


Here's a picture of where the CFB-5 connector is supposed to be -
http://www.biggerhammer.net/mediaroo...up_general.jpg


Any techs out there know how to adjust the G2 levels without the CFB-5 connector? Do you have a service manual that explains how to adjust it on the 1270.

 

[Brian Hampton]

Yeah,


G2 on a 1270 is different. You have to do the other method described in the manual. Get the jumper connector from where manual saya to find it and short the 2 pins you found to disable AKB, then set G2 by eye as described in the manual.


-B

 

[Tim Smith]

Thanks Brian. That's a bummer. I was hoping there was a more absolute (objective) way to set the G2.

 

[Brian Hampton]

Hey,


For what it's worth. I no longer believe in the 4 volts method.


When I first did my G2's to 4 volts I was really happy. Everything looked great to me at the time and I had the notion it was all set to spec. Eventually though I wanted to get the blacks that CRT's are rumored to have. With the 4 volt setting my bias values for the tubes had to be pretty close to zero to get blacks that were black.


I have done both methods and using the eye method my voltages were usually pretty close to 3.5 volts. I think the by eye method is more accurate even though you don't have the 3 digit precision feeling you can get from a meter.


Good Luck,


Brian

 

[Tim Smith]

Well, I adjusted the G2 today and then calibrated the greyscale with a color analyzer. I think the biggest improvement has been gained because of the G2 adjustment (although I can't prove this since I needed to complete both before watching a movie). Before the G2 adjustment the pluge pattern was pratically all black. Now I can actually see the 5 ire spots.


I'm going to take a break and watch a complete movie later. Hopefully I'll still be happy with the adjustments after not looking at for so long.


Oh, and for those who use the "I am the Gladiator" scene from The Gladiator, I can now see the soldier standing in the doorway.

 

[Brian Hampton]

Hi,


Care to share your values post calibration? I assume you did the G2 with Contrast-80 and Brightness-50 and Bias and Gain at default (whatever values those were on your machine). If so it may be fun to set my values to the same as yours (precal), then adjust G2 as you did, then plug in your post cal values for Bais, Gain, Contrast, and brightness. Who knows, it may be fruitfull.


-B

 

[Tim Smith]

I haven't used my pj again, tomorrow I'll post the settings but I doubt they'll be of any use. I calibrated using avia on a dvd player going through a scaler. I'm sure the scaler and dvd player introduce their own coloring. In addition, my tube wear is different from yours, which would probably make the gain and bias settings useless. I ended up turning my red way down in both bias and gain.


As for the G2 setup - I followed mooneyass' setup manual by adjusting contrast to 80 and brightness to 50. I attempted setting bias and gain back to factory defaults but they remained at the previous settings. So I set bias to 140 and gain to 180, according to mooneyass' instructions. Then I shorted pins 1 and 2, looked into each tube face and adjusted the G2 controls for each until I barely saw the 5 ire patches. I then released the short.


Another note, I used an older Minolta TV color analyzer to set grayscale. I did it using xyY mode (as an absolute reference rather than trying to teach the analyzer my crt colors) which would hopefully lessen errors. This instrument is not very sensitive in low light conditions so I started at 40 IRE and went to 80 IRE. I was probably within +/- .015 or .020 for all IRE's in between.

 

[Brian Hampton]

Hey,


You actually don't need to post the settings. I had a momentary lapse of reason. What sounded like it could be a fun thing to just check is most certainly a waste of time. I know (I think that I know) people like WM keep records of settings when they calibrate and no 2 machines are calibrated to the same values.


Someday, I'll bite the bullet and get a color analyzer (or try to get WM to calibrate my FP) but not just yet as I got other stuff that's got to happen first.


Thanks and Good Luck,


Brian