Help calibrating a 1084 monitor with a new LOPT

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keropi
Posts: 323
Joined: Sat Sep 20, 2008 9:33 am
Location: Ioannina , Greece

Help calibrating a 1084 monitor with a new LOPT

Post by keropi »

Hiya!

My 1084S-P1 monitor had a dead lopt and it changed with with the compatible HR-7533 LOPT. Everything seems great so I fired up the 240p Test Suite on the megadrive.
Picture is sharp, colors are correct but I have 2 issues that I think are related:

a. Backlit zone test
The square that you move around is blurry , ie the pixels are not sharp and well defined, infact they seem out of focus.

b. IRE test
At "13 IRE" the screen is kinda blurry / out of focus (maybe the backlit test above is the same mode?) . As IRE decreases so is the screen's sharpness.
Also I noticed that at "13 IRE" the screen "zooms out" a little.

I have an identical 1084S-P1 monitor as well and I did a comparison side-by-side. It is not affected by these 2 issues.
Could this be a limitation of the HR-7533 LOPT compared to the original Commodore used?
Is there something I need to setup? I have adjusted the LOPT FOCUS using the grid patterns and it's as sharp as possible , infact you cannot tell the difference between the repaired 1084 and the stock one with the factory settings.

I am attaching some pics showing the monitor in action, sadly I can't take a good one of the problems I described above because the background is black and the IRE lettering / backlit box are so white that it messes up the camera... but hopefully you can see in the "13 IRE" picture that the letters are not that well defined.

Any advice/help will be greatly appreciated, TIA! :)

http://i.imgur.com/T3TelQx.jpg
http://i.imgur.com/lLZ85QF.jpg
http://i.imgur.com/mPjOCXM.jpg
http://i.imgur.com/s7aCzRu.jpg
http://i.imgur.com/mSWXfVG.jpg
http://i.imgur.com/nMm4qa4.jpg
http://i.imgur.com/hVTt6HV.jpg
http://i.imgur.com/owBubHo.jpg
http://i.imgur.com/XZ7TgAZ.jpg
http://i.imgur.com/roqHqPV.jpg
http://i.imgur.com/UQAogoo.jpg
xga
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Re: Help calibrating a 1084 monitor with a new LOPT

Post by xga »

I wonder if caps need to be replaced?
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keropi
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Location: Ioannina , Greece

Re: Help calibrating a 1084 monitor with a new LOPT

Post by keropi »

I forgot to mention that. caps have been replaced several months ago before the LOPT failure and everything was working fine back then.
MKL
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Re: Help calibrating a 1084 monitor with a new LOPT

Post by MKL »

keropi wrote:I have an identical 1084S-P1 monitor as well and I did a comparison side-by-side. It is not affected by these 2 issues.
Swap chassis/tubes and see if it's tube related.
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keropi
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Location: Ioannina , Greece

Re: Help calibrating a 1084 monitor with a new LOPT

Post by keropi »

Not that keen to swap tubes since I will need to calibrate again both the lopt and the RGB values on the neckboard, plus the combo was fine before the LOPT failure.
I did test the 240p suite on the PCE though, all IRE tests are fine on it - even those close to zero.

I am thinking that there is some calibration I need to do because of the new LOPT , the fact that at the lowest IRE setting the screen zooms out a little could be related to some voltage setting.

edit:
called it a day, did a tiny compromise with the LOPT focus setting and closed the monitor - after 25 years it won't be perfect :lol:
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