Sony PVM possible sync issue?

[16shot]

Hello everyone,

First post from me on these boards although i've been lurking around here for quite a while

Having recently more or less inherited a Sony PVM-14L2, i seem to be experiencing an issue with it where a slight static wave appears at the very top of the raster (please see attached pictures).

Now, the problem occurs only when an ntsc 240p signal is fed to the monitor (example any low-res video game) and is *not* present with an ntsc 480i signal (example PC or Playstation boot sequence). Also worth mentioning is that it is only visible when the monitor is set on underscan or 16:9 mode as it remains hidden under the bezel otherwise...

Both my old japanese Playstation and Saturn produce this (again, in 240p modes only) through composite and s-video using official cables from way back in the day, i do not unfortunately have the necessary leads to try it out in RGB at the moment.

Upon investigating on the issue, i noticed quite a few of you ladies and gentlemen seem to use PVMs for classic videogames and so, wondered whether any of you guys experience the same thing with your very own unit?

Any feedback would be very appreciated indeed!

In advance, many thanks!

[fagin]

Move to RGB using composite sync.

If that doesn't "fix" it I suspect you have a problem with your chassis.

[16shot]

I see... Thanks Fagin.

Probably time to invest into one of those scart to RGB and sync cable then as it could be due to noise in the actual signal fed into the monitor...

Oddly enough as mentioned above the picture is indeed perfect when displaying in 480i, and in the case of the Playstation, the interlaced boot up sequence looks fine up until switching to low res, so one could never tell there's any problem as long as 480i mode is used.

I've had a thorough look into the service menu with the help of the actual service manual and everything seems fine in there as well, messing about a bit with the values in the sync/hold section does produce some change without really fixing anything.

Do you use one of those screens yourself Fagin?

In fact, may i ask anyone using one of those pvms with underscan/16:9 feature to try it out and see what kind of result comes out? Pretty straightforward, connect ntsc Playstation/Saturn using s-video or composite into PVM, fire up, switch on underscan and look out for any wobble/wave at the top 3-5 lines of the raster.

i do realize a lot of us around here are more or less allergic to all things non RGB but, it would be of great help!

Again, thanks a million!

[ryu]

i think it's because of the underscan. i've had similar "issues" with other pvm and pgm models.. iirc one had the exact same thing when the screen wasn't properly filled up.

just don't use underscan

[fagin]

I'll put money on it that it's a sync issue myself. Unless there is a (inherent) problem with the chassis, expanding the edges out won't suddenly alter the image. Having a wavy edge only or compression is another story, but that is not what the OP has imo.

16shot,
No I don't own a PVM unfortunately, but I have seen similar "issues" with other set-ups I have had and "cleaning" the sync corrected it. But I know plenty of people who own PVM's, use RGB and don't have the issue.

The worse thing that will happen is that you'll invest in an RGB cable and you'll get an overall much sharper and nicer image at the very least. So it wouldn't be a total loss.

[ryu]

isn't the wavy edge most likely a geometry issue? i was talking about the 3 lines he's got on the top on these pictures

[16shot]

Oh i'm positive this is a sync issue as the geometry on it is spot on when checked using test patterns from my PC, which seems to carry a fairly 'clean' sync signal.

Hehe i guess i'm trying to find out whether the monitor is more or less functioning the way it's supposed to. Production and TV studios are currently literally binning those out but then they have been through some serious abuse you can instantly tell.

Granted Ryu, there is no real use for underscan when casually playing some games on this which i am, however, it can come in handy when hooking up a supergun along with one of those crazy 'overscan beyond the overscan' Irem pcbs for instance. 'Casual' yes, but hey! one never knows

Right you are as well Fagin, definitely worth seeing what can be done about that RGB cable. Will do that and get back with some results.

Thanks for your input! Keep'em coming!

Cheers

[fagin]

isn't the wavy edge most likely a geometry issue? i was talking about the 3 lines he's got on the top on these pictures

Yes I'd agree that a wavy edge is probably geometry, but the OP's issue is not a wavy edge.... his wavyness is coming in through the video signal in the top corner for well over a couple of inches. You can see that pretty clearly on the test grid. Look closely at his picture.

[fagin]

Oh i'm positive this is a sync issue as the geometry on it is spot on when checked using test patterns from my PC, which seems to carry a fairly 'clean' sync signal.

It will be a tad more than "fairly" clean... it WILL BE clean coming from a PC.

[gray117]

This is 'normal' as far as the working of your monitor is concerned.

Why it happens though I never really found out - it may well be a sync issue.

I must admit that 'back in the day' if I was making some widescreen video to be shown on a 4:3 display I'd prepare a letter boxed 4:3 version just to avoid things like this, that odd lighter/darker black border you can get on other screens or some exhibitor deciding to stretch the picture vertically 'because it looks better filling the screen' [argh that ratio ignoring attitude still makes my skin crawl].

I had always assumed it was supposed to be some kind of a scan marker, very common on sony trinitrons, probably to help with vertical alignments - this was at a time when you were simply lucky to have any widescreen support at all... but perhaps it is perfectly avoidable...?...

[16shot]

Thanks for your input Gray!

It does indeed look as though there isn't so much wrong with this set in the end...

I've had a chance to try it out with my Wii through component, the Wii's interesting since a few Virtual Console titles will allow switching to their native resolutions. The conclusion i've come to is that the distortion occurs only in NTSC 240p mode (on the Wii as well, faintly), all other modes are fine (including PAL interlaced and non-interlaced modes).

Perhaps something one of those sync cleaners would get rid of who knows...

To be honest, after having witnessed the quality of the picture through component, i'm finding it a bit difficult to blame the monitor for any fault at all... It looks nothing short of mind-boggling!!!

[16shot]

... Bumping this thread a little...

Got a Sync Strike involved in an ultimate attempt to tackle and isolate the cause of the squiggle issue i'm having with my monitor (see first post) so thought i'd get back with some results.

Everything works beautifully, as said before it is hard to imagine how the picture quality could possibly be any better. And while the Sync Strike does improve the overall stability of the signal, the squiggle, sadly, is still there.

This leaves us with the only possible cause being some kind of fault (?) with the PVM itself.

Fagin, having spotted your recent catch of a 14M4, which is the direct ancestor of the 14L2, have you actually noticed any of this stuff on your unit?

Sorry for my insistance on this. Any extra feedback at this point would be very appreciated, as i might consider full-on maintenance on this monitor while Sony still offer support on that model.

Thanks guys!

[fagin]

By using the Sync Strike you have erradicated a sync issue imo. I would suggest it's potentially a problem with your chassis then as I get no such issues. I know a few people with PVM's and this is not an issue. Sorry. The fact that you have tried this on two sources would also indicate a target device issue.

[16shot]

The fact that you have tried this on two sources would also indicate a target device issue.

Precisely, thanks for the feedback!

Time to look into servicing the bastard... It essentially boils down to either get it refurbished by professionals, or play a game of russian roulette and locate another monitor locally, at the risk of ending up with a pile of semi-defect PVMs

The Sync Strike does not lie that's for sure. Proof of this is the monitor's on screen menu system now displaying consistently without failure or flicker when in 240p, presumably due to even/odd lines being redrawn in the right order at all time.

[kamiboy]

Hey

My friendly neighbourhood FedEx delivery guy arrived at my building with a minty, mint 14L2 yesterday.

I was all excited to test a whole bunch of systems on it until the logistical implications dawned on me so I settled for just 3, NES, SNES and RGB modded PC Engine.

Unfortunately my Core Grafx seems to have given up the ghost since last I used it. It refuses to turn on, so I ended up only testing NES and SNES.

As for the underscan top screen shaking issue that you were experiencing, I can confirm that the same problem is present on my display when playing the NES, complete with the same curved upper right corner.

The SNES image does not fill enough of the screen to reach the area that exhibits the instability so I cannot confirm it either way for that system.

In any regard, what the deuce are you thinking playing games in underscan anyway? It looks ugly, especially with those three coloured raster lines at the top and shrunk image on the already too small 14" screen.

Just toggle off the underscan and play games as they were designed to be played, with overscan and worry free.

[16shot]

Thanks a million Kamiboy that was fast i truly appreciate!

Very interesting... So it does look a lot like the 14L2 doesn't *fully* support 240p video signals!

yes that underscan function isn't exactly flattering is it, it does however prove useful for arcade pcbs or ports that use the full raster including the overscan area (R-Type being a well known example).

Other than that, sorry to hear about your PC Engine, blown fuse i would've thought?

[kamiboy]

Blown fuse is indeed what I am thinking too, so I went ahead and ordered som 1a fuses. I have some 1.5a ones left over from the blown fuse on my SNES, but from what I hear I am supposed to use a replacement fuse with the the same amperage rating or less, never more.

We'll see when the fuses arrive, hopefully for the weekend for once.