Lack of contrast on PVM 20M4E.

[lettuce]

Sorry about another Sony PVM/BVM thread (maybe we should call this sub forum the SONY PVM/BVM forum lol). I am using a VGA 2 BNC cable in conjunction with the SyncStrike to connect my retro RGB consoles up to the PVM 20M4E but am not happy with the amount of contrast im getting from the PVM. The contrast level is around a normal level (not too dark and not too bright) but i have the contrast knob on the front of the PVM turned up to max, so i cant get anymore contrast out of the display, i always like my contrast slightly higher than normal for gaming but im not able to achieve this.

Fudoh, has suggested that maybe i need to add BNC terminators to the Output BNC plugs on the RGB lines, i have order 4 for less appox 3 quid, but if these dont do the trick do any of you PVM/BVM or general tech heads have any other suggestions as to why the contrast level seems to be low. Does altering the voltage on the flyback adjust the contrast or is it the brightness that alters??

[kamiboy]

You want more contrast so colours pop more right? If so then your problem might not be the contrast knob but the fact that for most displays of this nature you cannot fiddle with the colour knob when using RGB sources.

Try hooking up a component or S-video source which both allow for the latter and see if fiddling with colour helps or not.

Might also be prudent to explore the various menu options that effect image quality, such as temperature etc. to see if nothing is set to a wrong amount. Or even better, just reset everything to defaults to get rid of any wrongful tampering.

[lettuce]

You want more contrast so colours pop more right? If so then your problem might not be the contrast knob but the fact that for most displays of this nature you cannot fiddle with the colour knob when using RGB sources.

Try hooking up a component or S-video source which both allow for the latter and see if fiddling with colour helps or not.

Might also be prudent to explore the various menu options that effect image quality, such as temperature etc. to see if nothing is set to a wrong amount. Or even better, just reset everything to defaults to get rid of any wrongful tampering.

Thanks for the info, the colours do seem to be 'off' something just not right!?. But i dont think its the colours thats causing this issue, i mean if you had the the contrast knob turned all the way to max you would think the picture would look all wrong in that it would be to bright and over bearing but it isnt, with the knob cranked all the way up its just at a 'normal' level.

I have glanced over the manual and i know how to reset the 'service menu' to default but what about the normal menu? Fudoh did suggest trying a composhite signal but i dont have any cables to connect to the PVM as the SS doesnt accept a composhite signal and the only composhite console i have is the NES which i use a 2 phone to scart cable with

[kamiboy]

Usually the menu reset function is in the menu. Usually the last option pane.

You don't have a single coaxal cable around in your place? You must have some for audio or what have you. Connecting the NES should be easy then.

[lettuce]

Usually the menu rest function is in the menu. Usually the last option pane.

You don't have single coaxal cable around in your place? You must have some for audio or what have you. Connecting the NES should be easy then.

ill have a look in my draw of crap. Ok have found to BNC adaptors, can these only be used with phone plus or can it be used with on a r/f arieal lead that comes with a megadrive or snes?

[Fudoh]

You can use them with composite video cables, but not with RF signals.

[kamiboy]

ill have a look in my draw of crap. Ok have found to BNC adaptors, can these only be used with phone plus or can it be used with on a r/f arieal lead that comes with a megadrive or snes?

If the cable connectors fit then you should be able to use it.

[ryu]

has anyone else owned a medical pvm? i wouldn't be surprised if the contrast was capped on these since it probably wouldn't be necessary for medical applications (it might even counteract them...).

[Fudoh]

good point!

[RGB32E]

I've never found another PVM-2030 out in the wild that gives as high of contrast as my own PVM-2030 that I picked up virtually brand new. I think it's in part the mileage of the particular PVM you have, and the tube design and condition. Have you played around with lowering the brightness to give more pop to the image? Lowering the color temp to somewhere around 6500K can help too. Also, how dark is the picture surface of the tube under normal room lighting?

[lettuce]

Ok have just tried the NES, the contrast does seem to be slight higher, but only till about half way anything over half way to max doesnt seem to increase the contrast much more. The brightness on the other hand is alot brighter than on the RGB inputs

[lettuce]

Picture via composite,

http://www.youtube.com/watch?v=w6W7mZZo ... e=youtu.be

defiantly needs the red guns convergence sorted out

[kamiboy]

Yeah, it is worth remembering that wear has a deteriorating effect on picture vibrancy.

That being said, there should be something in the service menu to adjust the contrast clamping taking place. I believe that colour convergence issue should also be adjustable.

Seem like you need to break out the old service menu and just start fiddling with values. Turn the contrast knob all the way up and increase/decrease values until you see a change is as good a place to start.

Better save opening up the chassis as a last resort.

[lettuce]

Yeah, it is worth remembering that wear has a deteriorating effect on picture vibrancy.

That being said, there should be something in the service menu to adjust the contrast clamping taking place. I believe that colour convergence issue should also be adjustable.

Seem like you need to break out the old service menu and just start fiddling with values. Turn the contrast knob all the way up and increase/decrease values until you see a change is as good a place to start.

Better save opening up the chassis as a last resort.

Well there a sticker say model number and serial number, and has September 1998, so guess thats how old the tube is. I would have thought these monitors would have a realy long life as i remember in Fagins BVM YT video he said his BVM was over 25 years old and still had an outstanding picture.

So you think there should be convergence options in the service menu??

[kamiboy]

On the newer high end sets I would expect such options to be available in the service menu. Not sure about a medical model from '98.

[fagin]

There is no such thing as chassis based convergence adjustment on these sets.... if you want that kind of adjustment it's a BVM only!

IMO termintors are not needed.... I certainly never needed them on my 14" version.

Sub contrast (under sub control) is what you want to look at via the service menu. This maybe capped quite low which is why you're not seeing much adjustment via your "knob".

BTW high contrast is BAD. It's adds lack of focus and if you have a PVM that's defeating the idea of such imo.

To set anything up properly you really need a color bar set-up to check against (and test grid etc). PM me your postcode.... I'm sure you weren't that far away from me.

What console is that in the video..... to check convergence you really want some white text on a black background imo. A nice test grid will show this immediately.

[fagin]

I've just realised that the video you have posted is composite...... you can't judge convergence from a composite picture mate!

[fagin]

Just do a FACTORY RESETTING cycle and report back (as already suggested).

[lettuce]

Just do a FACTORY RESETTING cycle and report back (as already suggested).

Ive flicked through the manual and cant seen a factory reset for the normal menu, only the service menu. The only resets im able to do is on some options in the menu like the contrast and colour temp settings, and just basically press the 'Reset/Blue Only' button on the front of the PVM on each setting. Is there s system wide Factory reset option?

Ive have one of the 'Mega EverDrive' flashcarts for my Megadrive, and have a program called '240p Test Suite'....

http://junkerhq.net/xrgb/index.php/240p_test_suite

not sure if any of you guys have heard of it or even used it, but i can use that for setup.

[Fudoh]

Artemio introduced it here on the board, so of course we know it (and use it).

[lettuce]

Artemio introduced it here on the board, so of course we know it (and use it).

Ah probably before my time here then maybe

[fagin]

Just do a FACTORY RESETTING cycle and report back (as already suggested).

Ive flicked through the manual and cant seen a factory reset for the normal menu, only the service menu. The only resets im able to do is on some options in the menu like the contrast and colour temp settings, and just basically press the 'Reset/Blue Only' button on the front of the PVM on each setting. Is there s system wide Factory reset option?

Ive have one of the 'Mega EverDrive' flashcarts for my Megadrive, and have a program called '240p Test Suite'....

http://junkerhq.net/xrgb/index.php/240p_test_suite

not sure if any of you guys have heard of it or even used it, but i can use that for setup.

Point 10 Page 16.

[lettuce]

Point 10 Page 16.

Ah yeah did see that, i thought it was just for setting the service menu back to factory settings not the normal menu, but appears to have done both!!

On think i have noticed though is what ever the dial are set at on the front of the PVM when you do this factory reset it takes this position as the default (middle) position after reset. So this way i can turn the contrast know all the way down and do the factory reset and then i can boost the contrast more as it will amp up more.

Question about the Aperture and Phase Controls, the aperture is supposed to adjust the sharpness of the screen but appears to change nothing and the Phase is supposed to add a green or pinkish tint to the colour but again appears to change nothing when altering the knob, any ideas why these 2 knobs appear to do sod all??

[gamefan71]

Point 10 Page 16.

Question about the Aperture and Phase Controls, the aperture is supposed to adjust the sharpness of the screen but appears to change nothing and the Phase is supposed to add a green or pinkish tint to the colour but again appears to change nothing when altering the knob, any ideas why these 2 knobs appear to do sod all??

Both of those controls are disabled when using the RGB mode.

[lettuce]

Both of those controls are disabled when using the RGB mode.

Booo no far!!

Im alot happy with the display im getting from the PVM now...




http://www.youtube.com/watch?v=dkB6GDSy ... e=youtu.be

watch in 720p for scanline fest!

[kamiboy]

Indeed, nothing can quite beat a scanlined bossom.

I must commend you on your choice of game as well.