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Hitachi gone green

JCM
11-03-2006, 07:14 PM
My two-year-old 51F510 has recently developed a definite green cast. I've adjusted the user-available controls to reduce the green as far as it will go, and I've boosted all the other colors to the max, but grey scenes are still showing up slightly green. I watched a little of "Make a Deal" on a different TV yesterday, and the girls' dresses were blue. On my Hitachi, they were green. Oddly, whites are still pure white.

Anybody have any advice I'm tempted to take the back off and reduce the green pot, but the last time I did that it was back in the '60s -- and the color on that set was never the same again. Can I even do it with this TV, or do I need to get into the service menu? Or -- tell me it ain't so -- do I need to get a technician to come out?

I searched the ISF site and got a line on a nearby ISF calibrator who goes by the name of Chad B, working out of Richmond, VA. Anybody have any experience with him? His website is at http://www.hdtvbychadb.com/.

d6500k
11-03-2006, 07:52 PM
I'm tempted to take the back off and reduce the green pot,

Whoa there big fella....

That "pot" has moved some since the 60's;)

Before you tear into too much stuff, check all of the input connections. Could be something as simple as a Blue component cable being a bit loose.

Chad has the tools to calibrated your display BTW.

Doug k

JCM
11-04-2006, 09:36 AM
Thanks for the quick reply.

All cable connections are tight, and the excessive green cast is present on all inputs: two use component cables and two use composite. The 51F510 has a large number of picture settings the user can twiddle with -- one of the reasons I bought it. Red and blue are definitely there, and bright.

I see no alternative to getting a technician in, but I wondered if anyone had any idea what might have caused the problem. I don't think I've ever read of this particular problem before -- that is a color shoots way up in intensity for no known reason. I did a search using just "green" on this forum and read through a whole bunch of postings. Have any of you techies ever encountered it?

d6500k
11-04-2006, 12:33 PM
Panasonics were known for a "POP" which was a precurser to a similar condition you seem to have encountered. It would radically intensify the voltage thru a screen VR (pot), thus making the affected gun much brighter than it need be. I've seen it on Hits. as well, just not as often.

To test, look for scan lines in the raster. These appear as curved arcs about 5 to 10 inches apart. The best way is to remove the screen and peer into the guns themselves (black screen). Obviously, your green gun (center) is the one to check first. If removal of the screen is not your cup'o'tea, then darken ther room completely. Input no signal (black screen) and look for the scan lines in the raster. If seen, you may then wish to call for a tech, or remove the speaker grill, locate the focus pak and the green (POT) which will be marked as Green Screen. Turn it down until the scan lines are just gone, up until you see them just barely, then back down to just gone. You can count on the grayscale being hosed after this procedure, but it already is anyway. Be really sure that you are on the green screen control as the focus pots are on the same pak and sometimes the whole assembly is upside down. Just be sure.

I highly recommend that you hire a tech for the procedure as he will most probably measure the actual voltages and set them accurately. But, with care, and since you have "done it before" it is not that tough and will most likely do the job. A service manual for your display would be a good thing to have at your side.

Good Viewing,

Doug k

madison square
11-16-2006, 07:08 PM
I have a Hitacchi 51F710 that had the same problem,only that it took on a purple tint . This was after 7 months. I had a Hitachi tech come to see what was wrong. He said that the red gun had drifted ? He took off the front of the unit, speaker grill and got access to the units color guns. He then adjusted them by turning some knobs on them he did it by eye no meters. It looked good and left. I then relized that the picture had now taken on a green tint. Had him come back. He again adjusted and left. Sets blue gun was set to high and picture looked worse then before. I then decided that i would get an ISF tech to calibrate it and see if it would make a difrence after reading about calibration. I contacted Kevin Miller at ISFTV to do the calibration. Well to all the people who say that calibration by an ISF tech is not worth the money, i would now say it is worth every penny. Kevin spent over 2 hours adjusting grey scale,convergence,focus,and readjusted the color guns to industry standards.End result a picture that now kicks ass. The colors are now so vivid and accurate that this RPT looks as good if not better then any plasma or Lcd i have seen in Circuit City. Calibration is definitlly worth the money if you want the kind of HD picture these sets are able to produce. You can contact Kevin at [email protected] if you have any questions as he sure helped me

JCM
11-19-2006, 03:34 PM
I've decided to go with an ISF calibration. I'm trying to set up an appointment with a local ISF calibrator (but he hasn't been in contact with me much so far). I'll let you know how it goes.

Meanwhile, I ordered a service manual. I may try to do an eyeball calibration to get the green back to a reasonable level.

I mentioned this in another posting but not here -- my black level changed about the same time as the color balance. I was able to readjust that with the user-accessible controls, but I haven't put in the time needed to get the picture back as good as it was before. Another reason to look forward to an ISF calibration.

I've been doing some searches out in the great wasteland of the Internet and found a few more people who had a similar problem. One posting was by a technician who said the color gains were "very critical," meaning, I guess, that a small adjustment produced a large color change on the screen.

billcherjen
11-23-2006, 05:51 PM
I have an Hitachi 51G500S that developed a green tint after a few months. The other colors are just OK. I would like to get an experienced ISF tech to calibrate my set, but I don't know of any in this area (15 mi. east of Pittsburgh, PA). Can anyone recommend a good ISF tech around here?

d6500k
11-23-2006, 06:23 PM
http://www.highdefforum.com/showthread.php?t=30869
Should lead you on the path to a calibrator.


Doug k

JCM
12-02-2006, 11:30 AM
D6500k,

I'd like to thank you for your advice. :bowdown:

I got the service manual as you suggested and adjusted the green pot as well as I could by eye with the color setting turned all the way down. The pot is very touchy, I found -- small adjustments result in big color changes. Then I checked each of the color temperature settings until I found one that gave me grey greys. It turned out to be "high," whereas I was using "medium" before. The picture seems to be back to normal now.

I'm sure I'll still have to do some tweaking with the user controls, but at least skies are blue again, and black-and-white movies are really black and white.

Also, I made an appointment with Chad Billheimer for later this month. I'm hopeful he'll be able to really improve the set's picture performance.

madison square
12-17-2006, 06:04 PM
How did you make out with the calibration. Did it solve the problem of the green tint. My Hitachi 51f710 looks outstanding since i had it calibrated. Football games are terific as is most of the braodcasts in 1080i. It is amazing the diference in some HD programing over others. The local news on NBC is just beautiful,ABC local new has started to broadcast in HD but its just not as sharp as Nbc. Does the fact that NBC is in1080i and ABC is in 720P the reason . I have Cablevision with a 8300HD set top box. The ISF tech who did my calibrated did mention that garbage in garbage out. I would not say that ABC local news is garbage in but it just does not measure up to Fox's 720p broa:hithere: dcast football games. Anybody have any thoughts.

JCM
12-18-2006, 08:14 PM
I'll let you know. The big calibration day hasn't come yet.

After living with my tweak for a while, I will have to say that I didn't get the grey greys I said I thought I had in my last post. Sepia greys is more like it. Dark scenes are kind of a reddish brown. Still better than green, though, so I didn't try to tweak it any more by eye. I wouldn't know what to change to get the colors back in balance.

d6500k
12-18-2006, 09:49 PM
Still better than green, though,
Yea Brother!

Your probably looking at d55 or so which is really great for B/W films BTW.

At least the green is gone...

Merry Christmas!

Doug k

JCM
12-30-2006, 08:59 PM
I promised madison square a report on my ISF calibration, and here it is.

Chad Billheimer was here today and worked his butt off. The results are extremely satisfactory. He spent most of the day working on the TV without a break, other than to answer my questions. He has a great work ethic, and he is very knowledgeable. Not only is the greyscale back where it should be, but the colors are more vivid without appearing artificial. He cleaned the lenses, sharpened up the focus, straightened out the geometry, and perfected the convergence. Probably did a few other things that I'm not aware of. My hat's off to him, and I would recommend him to anyone.

If you are at all dissatisfied with your picture, the ISF calibration is worth the money, in my humble opinion.

After he left, we watched some Dish HD programming and then played the pilot of "Lost" on my ancient Sony 480i DVD player. He did an extra tweak on the DVD input, because my Sony doesn't have an adjustment for black level.

Frankly, I think standard definition DVD beats Dish HD hands down. But again, that's just my humble "O."

kfalls
03-12-2007, 07:37 AM
I took an ISF calibration class a couple of years ago thinking I would get into calibration as a side job. When my day job was eliminated because of downsizing I put this on-hold until I could find another permanent job to hold me until I can establish a business.
In the mean time I had the same "pop" problem I've read in this thread where the screen had a green tint. I connected my grayscale sensor and computer and found my grayscale was way out of calibration. Once calibrated everything looked "right" again. I'm a big supporter of ISF calibration and have seen first-hand its results. Always well worth the money.

madison square
03-12-2007, 05:23 PM
Thats just what the ISF calibrater found when he calibrated my Hitachi. Once he got the gray scale to where it should be 6500 or as close as he was able to the picture was beautiful. I just don't know why it went so out of whack as it was fine for 7 months.