Can someone help with geometry on a Hitachi 51F500? - AVS Forum | Home Theater Discussions And Reviews
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post #1 of 5 Old 02-13-2003, 02:00 PM - Thread Starter
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I picked up a Hitachi 51F500 last month and I have a small problem.

When I am watching 2.35:1 movies the top and bottom of the image don't form straight parallel lines. This is most noticeable on the bottom left side of the screen, which has a very noticeable curve. It almost seems like the top and bottom of the image are bowed in slightly though I haven't put up a straight edge to the screen to see if the curve on the bottom left is fooling me into thinking the whole display is bowed in. I have been lurking on this forum and have tried searching for information on the web but I haven't had any luck finding a way to fix this.

Can anyone point me in the right direction? I assume that the service menu will allow me to adjust the geometry and I can get into the service menu by hitting input while turning the set on. I just don't know what items would need adjustment to fix my problem.

Joel Keranen
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post #2 of 5 Old 02-13-2003, 09:07 PM
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Not to sound impolite, please think in the contrary...however, if you do not know what the register items in the service mode are, then I would caution you and advise against going in there and attempting to do this.

That is not to say that after acquiring a service manual you should not attempt it, just don't gain access and start adjusting things.

Hitachi's aren't particularly difficult once you have a degree of familiarity, but they are rather convoluted if you are going at it blindly. And, they are somewhat convoluted with the geometry and convergence navigation (there are three tiers of adjustments in varying gradients).

I don't mean to overly discourage you; it's just that I wouldn't want you to have a problem that puts your set into service. :)

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post #3 of 5 Old 02-13-2003, 10:26 PM - Thread Starter
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Yes but if someone could post the values that need to be adjusted and a procedure for adjustment it would be quite possible to do it. I know that I can buy a service manual and I will if I can't find other sources for adjustment information.
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post #4 of 5 Old 02-13-2003, 10:30 PM
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Here is the mode to adjust geometry and convergence. Pratice makes perfect as far as I am concerned.

1) Receive an NTSC signal.

2) Press Magic Focus to begin magic focus

3) Press magic focus again during the magic focus process to get the ‘stop’ screen

4) While stop screen is up, press "STATUS" or "INFO"on the remote control (R/C) to bring you to DCAM mode and the service grid (64 point grid)

5) When you first get in here… I believe red is the selected color by default (it is flashing).

6) To choose other colors to converge, use the following buttons on the R/C:
a) “STATUS†- Green
b) “0†- Red
c) “ANT†– Blue

7) Start from the center of the screen and work your way out on one color at a time. I adjusted red across the whole screen to match green. Then I switched to blue, and adjusted that to green as well. After you adjust blue, you may want to go back and adjust some red again… etc. until the convergence looks good.
(a) Use 4, 6, 2, and 5 on the R/C to move the cursor position(dotted lines).
(b) Use thumb stick to move the convergence point color.

8) I did not adjust the green at all. I use the green as the guide and did not adjust the location of any green point. This is highly suggested unless you have geometry problems.
9) When going along the lines and adjusting, you may run into the problem of getting an ‘S’ curve on the line. You’ll know if you get there. Basically, no matter what you do to adjust the line to be converged, the middle of the line between the points will not straighten out (it bends between the points). To fix this, the manual recommends going to the (7x5) mode which gives you less points to adjust. I had this problem, and the solution worked. There is also another mode (3x3) which gives you even less points. Basically, if the set looks good, you only fine tune it in (13x9) mode (64 point). If you have serious problems, the grids work as:
3x3 – ‘coarse’
7x5 – ‘medium’
13x9 – ‘fine’

10) To get to each of these patterns use the following on the R/C: (only if you need to)
1. (3x3) Press “STATUS†5 times (only works when DCU is in uncorrected state)
2. (7x5) Press “0†5 times
3. (13x9) Press “ANT†5 times

11) If you adjust the 3x3, then you should go to the 7x5, and then the 13x9. You get the point… depending on where you start, work your way up, and always finish on the 13x9

12) When finishing up the 13x9 mode, to get additional ‘grids’ on the edges of the screen, press the PIP CH button on the remote control while in the digital convergence adjustment mode (DCAM). Fine tune the edge convergence as necessary. To exit, press PIP CH again.

13) When convergence is acceptable, press PIP MODE to write data to ROM memory. ROM WRITE? is displayed to alarm system that ROM will be overwritten with new data. Press the PIP MODE button again to write displayed data to ROM.

14) DATA WRITE TO ROM will take approximately 4 seconds and no picture will be displayed.

15) Green dots will be displayed when operation is completed.

16) Press MUTE to return to convergence pattern, then confirm again convergence is acceptable.

17) Press PIP MODE and then PIP CH to initialize Magic Focus. The initialize operation starts and several windows appear during this operation. It takes about 30 seconds or less.

18) When green dots appear, initialize operation is finished.
19) Turn power OFF.

21) Wait a few seconds. Turn the TV on, and you should have your normal signal. Press Magic Focus button just to make sure the magic focus still works (and that you did the last few steps properly)
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post #5 of 5 Old 02-15-2003, 08:03 AM
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There is some extra features besides those basics above too...

Menu button shuts off the CRT's not being adjusted

Pip channel gets you some extra lines for corner perfection and so on....

Took me two years of practice to get really good at it...

And don't forget to "PIP mode then PIP channel" before you turn the set off or you'll lose magic focus.

Read the whole post twice before doing anything
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