Fudoh's ode to old display technology

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Tempest_2084
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Re: Fudoh's ode to old display technology

Post by Tempest_2084 »

After a little more adjusting this is where I ended up. Once again that orange on the left really isn't there (well it is a little (it's a lighter red) but you can only really see it on the solid red RGB screen and only then if you're looking for it). It's not perfect (especially with the convergence in some spots) but at this point I think it's the best it's going to get. I may attempt a few strips to fix some of the minor convergence issues, but I think this is as good as I'm going to get it. As everyone keeps telling me, this is a low end trinitron, not a PVM.

Next up on the operating table, my PVM. it has some geometry issues but I'm NOT going to muck with the yoke on this one. Never again... :)
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Any tips for the convergence issues? I tried to minimize the horizontal convergence issue at the top of the screen by adjusting VR3 on the yoke, but that also affected it everywhere else so I ended up with decent convergence at the top but it was off on the bottom half of the screen. I did play with that dial on the neckboard (RV702) but that seemed to control some weird geometry setting where all four corners started to bow upwards. I quickly put it back to where it was (I hope). This is what I get for playing with strange dials. Would pulling up or down on the yoke maybe fix this?

Never did fix that vertical linearity issue on the left. I guess I'll just have to live with it.
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ASDR
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Re: Fudoh's ode to old display technology

Post by ASDR »

Looks pretty good already for big & flat Trinitron TV!

The horizontal linearity issue is strange, seems quite severe to me. Never know what to do about that, though. There's like a handful of TVs that have an SLIN adjustment, but otherwise? Hm.

Is this not your yoke, CCA, neckboard etc.?

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Should be pretty clear what everything is?

Those horizontal convergence issues at the sides can be fixed with those little pieces that slide in/out the side of the yoke, but they might not be installed. They only put those in at the factory if there's an issue to correct. I should look at one of mine if it's a magnet or permalloy or whatever. Maybe I can make my own with permalloy foil / magnet tape and a piece of cardboard or plastic, slide them into position and then fix them with caulk.
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Tempest_2084
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Re: Fudoh's ode to old display technology

Post by Tempest_2084 »

I honestly don't care too much about the linearity issue. Not much I can do about it without completely redoing the yoke again. The geometry is so good I really don't want to do that.

No it doesn't have that plate, but I wonder if the VR1-3 dials correspond to those adjusts shown in the manual

So you think the convergence issues can be fixed with those convergence strips under the yoke? I tried but I had no luck. All I did was throw the convergence completely out of whack.
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maxtherabbit
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Re: Fudoh's ode to old display technology

Post by maxtherabbit »

there might be a variable inductor in the h drive path to adjust the linearity, I've worked on monitors that have one
yoZe
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Re: Fudoh's ode to old display technology

Post by yoZe »

A lot of crt tv have horizontal linearity problems and I never found anything, either on the chassis or in the service menu to correct this defect.
I regularly search for a solution to this problem but I still haven't found anything until now.
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Tempest_2084
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Re: Fudoh's ode to old display technology

Post by Tempest_2084 »

Yeah I'm more concerned about the convergence issues at this point as those are far more visible. Unfortunately I'm starting to think I can't fix those without a yoke readjustment either.

One thing I never did in all this time was remove the bottom wedge. It was the only one that was still glued on and I figured leaving one on while I adjust the yoke wouldn't hurt. Do you think I should remove it and try adjusting the yoke again or is that wedge probably not causing any of my problems?
yoZe
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Re: Fudoh's ode to old display technology

Post by yoZe »

From my experience (and believe me I have reworked the image on a lot of crt's), from your pictures, readjusting the yoke will not improve the convergence. I think you already have a very good convergence.
You can at the limit bring a little better with strips in the corners but even with strips I am not convinced that we can obtain better than what you already have.
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Tempest_2084
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Re: Fudoh's ode to old display technology

Post by Tempest_2084 »

yoZe wrote:From my experience (and believe me I have reworked the image on a lot of crt's), from your pictures, readjusting the yoke will not improve the convergence. I think you already have a very good convergence.
You can at the limit bring a little better with strips in the corners but even with strips I am not convinced that we can obtain better than what you already have.
Good to know. I guess I'll do some testing and see if it shows up too badly in games then.
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Re: Fudoh's ode to old display technology

Post by Tempest_2084 »

Did some tests and 95%+ of the games look just fine. The 5% or so that have a display issue are mostly only visible if you're looking for it (i.e. you know the convergence is off in the upper right so you purposely look there to see the red bleed). There are a few games (very few) where the convergence issue is obvious, but it's only cosmetic and doesn't hurt the gameplay at all. Overall I can live with what I have, it's way better than it was.

My only complaint is that the upper right (and to a lesser extent the upper left) have a 'hook' or a 'horn' still that's most obvious in bright solid colored screens. I've played with convergence strips all day and I can either fix the hook or have normal convergence, I can't seem to do both. Unless someone knows of a SM option to fix this (UPIN doesn't help) I'm going to give up on it. Oddly, I seem to recall setting some option the last time I played with the SM that did affect 'hooking' in the corners. I seem to recall it being a binary option (1 or 0) and not something that had a range of numbers, but I can't seem to find it now. There are tons of options past the normal geometry settings that i have no idea what they do and I'm afraid to play with them as some of them seem to deal with power or frequency and that's a good way to break your set.

I do have a question for all you resolution experts out there. Before I started mucking around with the set I found that there were some pretty serious issues with different systems displaying in the overscan area. For example I had to underscan the Genesis to get the SNES to fit onto the screen and there was no hope that the Neo Geo wouldn't be chopped off unless I severely underscanned just about all my systems. Oddly enough I've noticed that now all the systems pretty much fit the screen with only a little underscan or overscan issues. Even the Neo Geo fits pretty well. What could have caused something like this? I'm not imagining it. Maybe it's due to the linearity issue?
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Tempest_2084
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Re: Fudoh's ode to old display technology

Post by Tempest_2084 »

Got one more question before I close this set back up. How does one figure out if the focus is set correctly? I *think* it is, but sometimes I wonder if the center of the screen isn't quite as sharp as it could be. Is this a 'judge for yourself' kind of thing or is there a good pattern to use?
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Josh128
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Re: Fudoh's ode to old display technology

Post by Josh128 »

Focus must be balanced from center to the top and bottoms. Best focus in center will leave you with blurry tops/bottoms/corners and vice versa. My Hitachi 27MMV20B manual says to put up a crosshatch and adjust focus for the 6th horizontal line from the top, as this should be the best balance. In the 240p suite grid with red outlines, that would be the 4th or 5th horizontal white line from the top.
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Tempest_2084
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Re: Fudoh's ode to old display technology

Post by Tempest_2084 »

Josh128 wrote:Focus must be balanced from center to the top and bottoms. Best focus in center will leave you with blurry tops/bottoms/corners and vice versa. My Hitachi 27MMV20B manual says to put up a crosshatch and adjust focus for the 6th horizontal line from the top, as this should be the best balance. In the 240p suite grid with red outlines, that would be the 4th or 5th horizontal white line from the top.
I guess I have it focused pretty well then. I just eyeballed it until the corners weren't blurry and the center area looked crisp. I'll take one last look before closing it up though.
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Re: Fudoh's ode to old display technology

Post by tongshadow »

yoZe wrote:A lot of crt tv have horizontal linearity problems and I never found anything, either on the chassis or in the service menu to correct this defect.
I regularly search for a solution to this problem but I still haven't found anything until now.
It's either bad polymer/ceramic capacitors that are responsible for the "S-Shaping" wavelength, and sometimes a bad coil, or just a flat tube being flat.
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Re: Fudoh's ode to old display technology

Post by yoZe »

tongshadow wrote:It's either bad polymer/ceramic capacitors that are responsible for the "S-Shaping" wavelength, and sometimes a bad coil, or just a flat tube being flat.
It means that some capacitors have lost their capacity or it's a chassis design problem with capacitors not having the right value from the beginning?
Otherwise, the problem is the same on flat or curved tubes.
I have for example 4 flat trinitrons with a FE-2 chassis which have no linearity problem.
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Tempest_2084
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Re: Fudoh's ode to old display technology

Post by Tempest_2084 »

The weird thing is I swear it didn't have this problem until after I started messing with the yoke. I figured I just didn't get the yoke back 100% in the right spot. Then again a cap could have started going bad in the year or so since I last fiddled with it.
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Re: Fudoh's ode to old display technology

Post by tongshadow »

yoZe wrote:
tongshadow wrote:It's either bad polymer/ceramic capacitors that are responsible for the "S-Shaping" wavelength, and sometimes a bad coil, or just a flat tube being flat.
It means that some capacitors have lost their capacity or it's a chassis design problem with capacitors not having the right value from the beginning?
Otherwise, the problem is the same on flat or curved tubes.
I have for example 4 flat trinitrons with a FE-2 chassis which have no linearity problem.
A little bit of both, it's hard to tell unless you have bought the display brand new. Here's a interesting document about H-Linearity.
http://www.gradllc.com/IMAGES/LINEARITY.pdf

With enough engineering and electronics it's possible to have perfect linearity in both axis on flat panels, otherwise the BVM-D24/32 wouldnt be flat nor considered the best displays.
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Re: Fudoh's ode to old display technology

Post by Tempest_2084 »

I decided to dig out some of my other 'backup' CRTs to see if they're any better than my Sony. First up is my Sharp 27SC260. It's a nice curved screen CRT that does component (don't know if the curved screen is a huge benefit or not). Looking at the grid however I noticed that the grid lines were 'squiggly' in spots. I tried to take some pictures but I don't know if the squiggles show up to well (you can see them pretty well in the convergence grid screenshot). Is this something that I should be worried about? I couldn't see how it affected the picture any, but I thought I read somewhere that this meant the caps were going. Beyond that, there's some small convergence issues on the top horizontal line (barely noticeable and better than my Sony) and the geometry on the top right edge isn't the best but it's not bad. I was actually thinking about using this one instead of my Trinitron but there are two issues. 1. The picture isn't as sharp (no pun intended) and 2. I can't adjust the geometry at all (the SM options don't do anything).

I'm wondering if I open it up and adjust the focus knob (assuming it has one) if I can increase the sharpness a little, but the corners are already slightly blurrier than the center screen so I don't know if that would be a good idea. I really do miss those Trinitron scanlines too. The second problem isn't too bad, but the picture really needs to be shifted a smidgen to the right and down as some games that like to use the entire screen are very slightly cut off. I could live with it if I had to, but it's really annoying that I can't do anything about it.

Any comments on this particular tube vs my Trinny?
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Genesis Grid
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Genesis Convergence
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SNES Grid (see the squiggles on the right near the red?)
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Tempest_2084
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Re: Fudoh's ode to old display technology

Post by Tempest_2084 »

My other backup CRT is a Sharp 27F543. This one has some issues that definitely need addressing. The grid doesn't look too horrible but needs some adjusting that I don't think can be fixed 100% through the SM (at least the SM works on this one), which means a yoke adjust. There's some more of those 'squiggles' and there also seems to be some sort of interference that you can see if you look very closely, especially where the red and white meet. The convergence grid on the other hand shows just how screwed up the linearity is on the right side of the screen. This is probably attributing to the biggest issue this set has in that it has bad 'barrel distortion' (I think that's the correct term) where the image 'warps' as it comes in from the side to the center and then warps again on the way out towards the other side. It's pretty noticeable on any side scrolling game. I'm thinking this one needs way too much work and is probably going to be given away to a friend of mine. Once again the screen isn't nearly as sharp as my Trinitron and has a 'screen door' look to it (is that shadow mask?) that I don't care for. The brightness is also somewhat dim unless you turn the picture and brightness way up which to me means that the tube is getting old (even though it's a 2004 model).
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ASDR
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Re: Fudoh's ode to old display technology

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Josh128 wrote:Focus must be balanced from center to the top and bottoms. Best focus in center will leave you with blurry tops/bottoms/corners and vice versa. My Hitachi 27MMV20B manual says to put up a crosshatch and adjust focus for the 6th horizontal line from the top, as this should be the best balance. In the 240p suite grid with red outlines, that would be the 4th or 5th horizontal white line from the top.
Yeah, something like that seems to be the textbook procedure. I honestly find it easy to adjust, just wiggle it back and forth a bit until it looks good.

I wanted to add on some fancier TVs there's a 'focus phase' setting in the SM as well that can further tweak focus. PC CRTs and fancy PVMs etc. also have separate hori/vert focus adjust.
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Re: Fudoh's ode to old display technology

Post by Tempest_2084 »

Last but not least here is my PVM 1943MD. This is the one I'd really like to get working to be my backup, but as you can see it has some geometry issues (no convergence issues thankfully). Any suggestions on how to fix the wonky geometry here? There are dials inside for all the standard SM adjustments (not nearly as convenient I might add) but geometry issues seem to be asymmetric, so I'm guessing it's going to take magnets or strips to fix. I really don't want to mess with the yoke which I fear will make things worse. Any suggestions?

Also there's a white 'box' on top of the yoke that seems to have two dials on it. They're labeled and I'm not sure what they do. Anyone know?
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SNES Test Pattern
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Genesis Test Pattern
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Convergence
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ASDR
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Re: Fudoh's ode to old display technology

Post by ASDR »

Tempest_2084 wrote:Last but not least here is my PVM 1943MD. This is the one I'd really like to get working to be my backup, but as you can see it has some geometry issues (no convergence issues thankfully). Any suggestions on how to fix the wonky geometry here?
Uh, this looks quite wonky indeed. Give the age of the CRT, might be time for a recap?
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Re: Fudoh's ode to old display technology

Post by Tempest_2084 »

ASDR wrote:
Tempest_2084 wrote:Last but not least here is my PVM 1943MD. This is the one I'd really like to get working to be my backup, but as you can see it has some geometry issues (no convergence issues thankfully). Any suggestions on how to fix the wonky geometry here?
Uh, this looks quite wonky indeed. Give the age of the CRT, might be time for a recap?
I wish I could find someone who could do that for me. That's beyond my abilities.

Any suggestions for something I can do with the internal dials or strips? What could those two dials on the white box on the yoke possibly do?
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Re: Fudoh's ode to old display technology

Post by Tempest_2084 »

This is where I got the PVM before I closed it up. All things considered it's not bad, but there's some bowing in the center (yoke sag) and the bottom right side pulls up a bit. I tried for an hour with strips but I couldn't really do much other than screw with the convergence. One of my problems is that it was actually quite difficult to even get one of the strips under the yoke on this monitor and the bottom right side is blocked by the board on the side of the case. Ultimately I think it probably needs a recap, but that's beyond my abilities. I wish there was someone in my area that did such things, I'd pay good money to have a recapped and adjusted PVM.
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Re: Fudoh's ode to old display technology

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maxtherabbit wrote:that's about as good as I've ever seen one of those WEGAs look tbh
You ain't seen nothin', then.
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(by no means am I calling that perfect, the vertical linearity is off - but that is my old KV-32FS100... all 100% done in the service menu)
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Re: Fudoh's ode to old display technology

Post by Tempest_2084 »

I'm jealous. :)

Honestly, I think my best bet is to look for another Trinny and hope it has better geometry/convergence than my current one. I don't think there's much more I can do with it.
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Re: Fudoh's ode to old display technology

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Tempest_2084 wrote:I'm jealous. :)

Honestly, I think my best bet is to look for another Trinny and hope it has better geometry/convergence than my current one. I don't think there's much more I can do with it.
My suggestion for service menu stuff is to focus hard on UPIN/LPIN, PAMP, VBOW... switch back and forth between anything involving bowing and pincushioning and you can really get those corners dialed-in
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Re: Fudoh's ode to old display technology

Post by Tempest_2084 »

kitty666cats wrote:
Tempest_2084 wrote:I'm jealous. :)

Honestly, I think my best bet is to look for another Trinny and hope it has better geometry/convergence than my current one. I don't think there's much more I can do with it.
My suggestion for service menu stuff is to focus hard on UPIN/LPIN, PAMP, VBOW... switch back and forth between anything involving bowing and pincushioning and you can really get those corners dialed-in
With my TV I spent a good hour or so playing with the service menu, but to fix what's wrong I need to either redo the yoke adjustment again and potentially screw up what I've got and/or get some magnets (not just the convergence strips I have) and play with those. As for my PVM, that I'm afraid probably needs a recap (or possibly magnets as well). Since the TV isn't a rare or desirable Trinitron model (it's a base KV27FS100) I'm more inclined to just find a better one and keep this one as a backup. For the PVM I'd love to find someone who can recap and adjust it, but as far as I know no one around here does that and there's no way I'm shipping it somewhere.
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Re: Fudoh's ode to old display technology

Post by kitty666cats »

Tempest_2084 wrote:
kitty666cats wrote:
Tempest_2084 wrote:I'm jealous. :)

Honestly, I think my best bet is to look for another Trinny and hope it has better geometry/convergence than my current one. I don't think there's much more I can do with it.
My suggestion for service menu stuff is to focus hard on UPIN/LPIN, PAMP, VBOW... switch back and forth between anything involving bowing and pincushioning and you can really get those corners dialed-in
With my TV I spent a good hour or so playing with the service menu, but to fix what's wrong I need to either redo the yoke adjustment again and potentially screw up what I've got and/or get some magnets (not just the convergence strips I have) and play with those. As for my PVM, that I'm afraid probably needs a recap (or possibly magnets as well). Since the TV isn't a rare or desirable Trinitron model (it's a base KV27FS100) I'm more inclined to just find a better one and keep this one as a backup. For the PVM I'd love to find someone who can recap and adjust it, but as far as I know no one around here does that and there's no way I'm shipping it somewhere.
KV-__FS100s are awesome! Just because they aren't that one with a PVM's voltage regulation doesn't mean they aren't desirable...
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Re: Fudoh's ode to old display technology

Post by Tempest_2084 »

kitty666cats wrote: KV-__FS100s are awesome! Just because they aren't that one with a PVM's voltage regulation doesn't mean they aren't desirable...
Oh I didn't mean it was a bad tv, I meant it wasn't one of those rare expensive models. To keep any Trinitron model is good enough for what I need. I'm looking for a 100 or 120 as a replacement.
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Re: Fudoh's ode to old display technology

Post by Tempest_2084 »

So I was able to pick up a JVC D Series tonight for $5 (av-27D304). I'm rather impressed with the set as it has nice geometry and convergence. The picture seems pretty sharp, but the scanlines aren't as nice as my Trintron. One thing I've noticed is that the geometry seems to change slightly with different games. For example take a look at Axelay, you can clearly see that the top pincushions inward. However now take a look at SMW and you can see that the pincushion issue is mostly gone. It also doesn't show up on the grid pattern so I'm wondering why it's there with Axelay. It also seemed to show up in LoZ: LttP when there was a bright white bar over the lake scene on the title screen, so now I'm thinking that it may only happen when the screen is very bright (although SMW is pretty bright at the top too). Has anyone seen something like this before? Other than that I'm very happy with the picture.

Axelay and SMW
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Here are some other pics I took on various systems (ignore the raster lines in some of them). I'm really considering using this set instead of my Trintron. The last picture (Goonies on the NES) is interesting because it makes the mice stand out a bit from the background while on the real TV they're much more red so they blend in a little.
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Oh and the obligatory grid shot
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Another thing I've noticed is that this set has a moderately loud buzz which is kind of annoying. You can't hear it when there's music going on but when it's quiet you can hear it pretty well. Someone told me that it might be the speakers and you can get rid of it if you use an external pair of speakers, but I'm wondering how that will work since I don't see an option to disable the internal speakers and use external ones like there is on the Trinitron.
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