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-   -   Pvm-8040 b&w? (http://www.videokarma.org/showthread.php?t=270720)

CRTs4life 07-26-2018 05:52 PM

Pvm-8040 b&w?
 
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Greetings VK friends!

I recently had a neighbor give me a pvm-8040 and a gvm1311q he intended to recycle or trash bin as he got them in a gov't auction and wasn't interested in the older a/v items. Happy to report the gvm-1311q is fine, I had no idea Sony made super fine pitch desktop monitors. I feel really lucky to have these instead of a landfill.
The 8" pvm works but is only displaying black and white. ?
As far as I can tell all of these 8040's were color. The monitor has a sticker on the front that says "DOC CAM". Maybe for police documents, etc?
I am puzzled and at a loss and I am a complete rookie with anything besides consumer CRTs.
On some pvms by pressing degauss and power you can access the service menu but this 8040 has no manual degauss.
There is no way I can find to adjust the color level like on a consumer.

Would any of you folks have any thoughts on this? Please and thank you in advance.

P.S.- The closest service manual I readily found was for an 8042 and not sure of finding what I needed.
Can anyone tell me what the white knob on the neck board/ca board adjusts?
Also, behind the tube, right side on the bottom there is a pot with a black, slotted knob for adjusting. Can anyone provide what that is as well?

Again, thanks!

P.S.S.- I tried two different input sources to make sure it wasn't the device or a cable.

zeno 07-26-2018 06:39 PM

White nob either focus, H Stat ( convergence ) or G2. Look at the FBT
& see how many pots are on it. Usually 2 ( focus & G2 ). That will narrow
things down. It wont hurt to turn it & see.
If the other pot is the one almost under the anode connector it looks
like a high wattage pot maybe for hoz centering or width.
Cant help with color. It may need a Sony remote to get to it or the
right button push combo.
BTW does this take composite video ??

73 Zeno:smoke:
LFOD !

Chip Chester 07-26-2018 07:43 PM

Could be the chroma is just turned way down, either by user-accessible control or PCB trimpot.

In edit suites of old (like CMX-controlled 1" and D2 edit bays) there was sometimes a document camera or title camera used to shoot title cards -- non-digital actual layout/paste-up cards of logos or other graphic elements. These were keyed over video using the switcher. You had to zoom in/out, focus, and frame or crop the elements for use in edits. Real old-school. These cams were usually black and white, so that monitor might be modified.

Bonus trivia: 3-D-looking "page turns" were done by Xeroxing the graphic element on acetate sheets (like thick paper) and the editor would hold the corner of the acetate and lift/turn the sheet for the effect. Pointless anecdote.

CRTs4life 07-26-2018 09:27 PM

Quote:

Originally Posted by zeno (Post 3202362)

BTW does this take composite video ??

73 Zeno:smoke:
LFOD !

Yes, it has both composite and s-video, both look very clear but b&w.

@Chip Chester - Build date says 1994 so I'm not sure if this qualifies as super old school but your theory is totally conceivable/feasible.

Next step I'll mark the pots and turn them to see what happens. To be cont'd......

Chip Chester 07-26-2018 10:25 PM

Get a copy of the manual first, before you commence t' tweakin'.

CRTs4life 07-26-2018 11:55 PM

The white knob on the neck board is convergence like Xeno mentioned, even marked H Stat. The black knob pot on the pcb is in fact the horizontal adjust.
The flyback transformer has 2 adjustments, focus and screen. No color when I moved anything (obvious to you guys I think) but I found it interesting that when I moved "screen" far to one direction all the edges showed the red green blue edge. (I am old enough to remember b&w tvs but I can't remember how the pixels looked up very close.) Anyway just talking. This pvm is so basic that it may not even have a service menu if that's possible, I definitely haven't seen a remote available for it either.
Thanks again for the comments, hopefully someone will recognize this model.

Electronic M 07-28-2018 03:23 PM

Monochrome TV did not have pixels...Some had scan lines or grain from coarse ground phosphor (both should be constrained to lower end or poorly adjusted sets), but there were no pixels...A monochrome CRT needs only one color of phosphor to work so the entire face can be evenly coated with it. A color CRT needs three phosphor colors (red green and blue) that evenly cover the face but each be kept separate from the other colors and individually addressable by the electron gun(s) and thus the three need to be laid down in separate discrete dots in an even pixel-like mosaic.


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