Ikegami TM2080 capkit

[kukrapok]

Hi all,

I registered on this forum because I recently acquired an Ikegami TM2080RP monitor and I'm having slight geometry issues with it:
1) The picture isn't perfectly symetrical, if I set it (trapezoid/pincushion) so that one side is straight, the opposite side will be slightly bent/wavy.
I could stretch the display horizontally to hide this problem but I'd prefer having a perfectly straight picture, or at least something as close as perfect as possible by replacing aging electrolytic caps if you think it would do the trick.
This issue is most noticeable when adjusting the pincushion to minimum or maximum, then you can clearly see that the vertical "center" isn't where it should be and it's uneven on the sides. (I can't imagine it was like that when the monitor was brand new?).
I just took a picture to show you guys how it looks along with a few other shots showing the overall geometry after I set it up the best I could.

2) The horizontal line at the top is slightly bent towards the bottom (this doesn't bother me too much)
3) When I center the picture horizontally and stretch the width, the picture moves slightly to the right, like it stretched the right portion of the screen more than the left.
I then have to move the picture to the left a little bit with the h.phase setting and stretch the width again. If I don't stretch the display that way, I end up with squares on the left and rectangles on the right. (I experimented with the settings and this issue could just be that I suck at setting things up, I managed to get something almost perfect)

Apart from that, the picture is really nice (especially after I calibrated with the ASP15 probe that I was lucky enough to find for a good price), I much prefer this monitor to the aperture grille ones.

I hope you guys will be able to help me with this as I really want to get the most out of this monitor and I think I already read about users capkitting their monitors, not sure if they were Ikegamis as they're less common than their Sony counterparts.


http://img15.hostingpics.net/pics/203820IMG1126.jpg
http://img15.hostingpics.net/pics/111729IMG1115.jpg
http://img15.hostingpics.net/pics/469233IMG1113.jpg
http://img15.hostingpics.net/pics/951959IMG1116.jpg

Cheers and thanks in advance.

[buttersoft]

If the third shot in your list is representative, I don't see the problem. Assuming you haven't set massive overscan to hide a distorted (coloured?) border, that looks fine for an aging CRT. Added to which, by reputation Ikegami made the most expensive, absolute top-of-the-line, best-ever broadcast sets. If the OSD and external adjustments don't cover it, there might be more pots inside (like the red gain, for one ) Check the service manual there.

Cap kits were most often for arcade monitors. Low-end monitors that were on 24/7. Stuff you open up and tinker with, that doesn't have trapezoid or pincushion adjustments or whatever. No one really does/did kits for broadcast and production gear, or if they did they can't have been common. If you were a really good tech, you didn't need them, you just used your own; if you weren't, messing around with a few caps wasn't going to help whichever superfine adjustment you needed to make - the caps wouldn't have a fine enough tolerance anyway, and the provided adjustments were meant to compensate for that variation. Added to which, recapping an older set isn't guaranteed to fix tiny niggles like the top center bowing down just slightly, though the pincushion probably would be affected if you did it right.

Lastly, the number of caps inside that thing is going to be phenomenal, and some of them might be really exotic. For the cube PVMs Sony used all sorts of two-part caps in the horizontal stages, constructed something like multi-leg bridge resistors but way larger, 2kV polymer stuff. Finding some of those would be impossible, let alone the expense. So you'd have to start modifying things, or just finding room.

I don't know enough about Ikegami to state that the same will be true. They were much more specialised and much smaller than Sony, and may perforce have used off-the-shelf components. Bearing in mind all of the above, open it up and have a look. You could always try to figure out which adjustments you really want to make, and target those sections.

Apologies for the largely negative post Tinkering is fun, and if you do go ahead, remember to be safe around the high voltages!

EDIT: You're implying people on here sell/list PVM cap kits? Is there a thread for that? I might be keen...

[kel]

buttersoft is right, your pictures are not very representative of the issue you are describing. From where I'm sitting that looks like pretty good geometry for a CRT.

From what you are describing it sounds like a horizontal linearity issue and if that is a copy of Castlevania SOTN I can see there then you will definitely notice if your monitor has bad horizontal linearity when playing that as it is a side scroller. As you are moving through the areas the picture will stretch and shrink a little as it scrolls from one side of the screen to the other. Is this the kind of issue you are referring to?

[kukrapok]

Thanks for your replies

No problem about the negative post, I have to say I was expecting most people to say that geometry looks decent on this monitor from those pics I posted and that replacing worn out capacitors would be difficult if it was possible at all.

I had a quick look inside the monitor and I didn't see that many capacitors, at least they didn't seem that numerous to my unexperienced eyes.
I thought it was just a matter of finding capacitors with the same specs
I will take a few pictures of the different boards later when I have time.

I guess I was using the wrong terms when saying "capkits" for PVMs but I'm pretty sure I already read posts of users replacing the caps on their pro monitors.
I remember seeing capkits for BVMs 20F1U on eBay recently, one guy was selling packages with all the capacitors needed in order to fix most geometry problems on these monitors, I'll try and find the link and edit my post.

I also found that link:
https://andynumbers.wordpress.com/2015/ ... -tm20-18r/
At the bottom you can read in the last paragraph that this guy replaced all the capacitors on his two Ikegami monitors' deflection boards.
One is a TM20-17 and the other is a TM20-18 with a pull out drawer just like mine, I'll contact him.

And yep, I can see the image distort itself in scrolling games, at first I thought it was mainly because it's very curved but it's not consistent across the screen. It's minor but I'm picky about that stuff and once you see it you can't unsee it. It's also noticeable on vertical scrolling games as I had to compensate with pincushion and it messes up scrolling around corners.

Thanks again for your help guys.

EDIT: Here's the capkit for the BVM, this specific kit is for D20F1U's but iirc the same seller was selling kits for the 15khz BVMs too so you might as well contact him, maybe he has more kits available.
http://www.ebay.com/itm/SONY-BVM-D20F1U ... 2070935616

[andy251203]

The 80 series is a newer, more modern monitor than the 17 or 18, and I don't have one so I can't really tell you much about it other than it is most likely completely different on the inside. Looking at your pictures, you don't need to change capacitors. My Ikegamis had major classic cap issues such as jailbars, foldover and a washed out image that were fixed by changing them. Your minor geometry issues won't be fixed by changing caps. Also, you probably have newer and longer lasting caps in your monitor, since it's a higher end model.

Like the other people here already stated, you probably just need to tweak your linearity adjustments slightly if the squares in your grid pattern are not all the same size.

[buttersoft]

I found it interesting that the blogger reports Ikegami as being cheaper and lower spec than the Sonys. I have to say I find the picture quality better on Ikegami, but then i've never seen a 20" one live. I've certainly heard that here in Aus, around '92-'95, the top-of-line BVMs were going for about $20K-$25K new, where the best Ikegami's were up north of $40K. The ABC filled old parliament house with smaller models, and changed them out every two years or so, which is unbelievable when you think about it.

Appreciate the links though, I'll have to give some thought as to what to do next

EDIT: Changing caps is a matter of getting the same spec, yes. Always use the same capacitance value, and wherever humanly possible the same type of cap (electro, tantalum, polymer). Voltage rating must be the same or higher - more than likely the manufacturer included a margin of error, but you wouldn't want to chance it. It's easiest to go one-for-one replacements, but you can work with parallel or series caps if you're confident using the calculators online. That can save buying high minimum quantities of multiple types in a few spots.

[Ikaruga11]

Aside from the first screenshot, your CRT looks perfectly fine.

[kel]

If it is a horizontal linearity issue then I doubt you will find any adjustments for it, not unless it has an adjustable horizontal linearity coil which i doubt but then I suppose you never know until you look.

The culprit will be somewhere on the horizontal output circuit or even the flyback transformer itself but less likely. If you are lucky it might be an electrolytic or ceramic cap but blanket replacing the whole lot will be expensive and could end in disappointment. It could also be the horizontal linearity coil itself but good luck in finding a replacement if so.

Ideally you would want to find or get hold of the service manual with schematics.

[SamIAm]

It never hurts to open up one of these things and eyeball all of the larger caps for signs of bulging or leaking. You might be able to find a power-supply board and a main yoke-control board with groups of larger caps, and these in particular are both likely to go bad early and give highly visible picture faults.

I've seen one Ikegami service manual, and sadly, unlike Sony service manuals, it didn't have a complete list of parts. I think you'd be stuck going in and recording cap values manually. It's quite the slog, and unless you see signs of caps going bad, I wouldn't bother.

Your pics look quite good for a CRT. If you don't see any obviously bad caps, I'd just leave it.