John's Arcade Forum - Classic Arcade and Pinball Collecting and Restoring Discussion Forum - RETRO MAME - Nintendo Vs Forum

ok so I spent an hour or so fine tuning my Millipede's monitor to a gorgeous picture, but then while letting it burn in for a few hours, it suddenly lost sync and when I got it stable again I got this droop in the image, cold boot or warmed up makes no difference, the image droops on the left side (which would be the tube's top) you can see what it looks like in this picture http://www.coinopspace.com/photo/img-20140314-202636 (http://www.coinopspace.com/photo/img-20140314-202636) I am fairly certain I need to do a cap kit, but I wanted opinions from you guys if there is anything else I should look at on the chassis that can cause this issue, I really don't want to have to take the chassis out more than once.
It is the original Matsushita monitor, I would normally replace the whole monitor due to the poor design, but in this case the tube checks out good and It had a great picture up till now.

Thanks for any suggestions you have on this.

one of mine just did that yesterday.
actually it did three whammies on me, it looked too green, sagged like your pic and needed a new neck board.
I did a cap kit , changed the neck board and one of the adjusters needed to be changed.
it was one of those 4600 style wg.

Yes, I would recommend you just doing a cap kit. I guarantee you it will fix all of your problems. :)

OK thanks guys, kind of figured that was what i needed to do to resolve the issue. I had just never seen this type of failure in a monitor before now, I guess I had been lucky  ;D

Always start with a cap kit so you can at least rule it out. And, it's preventative maintenance.

Ok so I capped this monitor, and while I was at it, re-flowed the solder to the potentiometers, the IC, and the header pins. and It has improved the situation, but it's not gone. It now only has the slight droop on 1/2 inch of the screen but only when it warms up and it stays on that area, so it's playable,  I'm going to try to adjust the B+ and see if that helps anything.

any Ideas as to what else to try? I still haven't replaced Big Blue yet or rebuilt the ARII, and those are next in line.
There is a service bulletin that mentions upping the voltage of one of the caps to 250V if you have sync problems So maybe I should try that?

I guess it didn't lol

Well turns out I was pretty dumb!  ;D ;D and when adjusting the monitor I did it by myself, and so when adjusting the old metal horizontal hold pot I couldn't find the proper setting. After I brought in a helper I just played with that potentiometer and voila distortion gone, so problem solved......and I'm a bonehead  :D

see the results http://www.coinopspace.com/photo/img-19800105-160201 (http://www.coinopspace.com/photo/img-19800105-160201)

hey man its all trial and error .
good you got it fixed.

Good work! Get a mirror next time. :)

Dude, that's why I'm a bonehead LOL  ;D had one and used it,  but I still couldn't get it right.

Don't feel bad! Adjusting monitors is a bit of an art form. You need to have an eye for it. I can't tell you how many games I got with really bad looking monitors. A lot of times they just needed about ten minutes of adjusting to make it perfect. Sometimes it's a lot of knob turning, other times you have to adjust the convergence, you'd be surprised how a bad monitor can turn good with just some minor adjustments. My Burgertime monitor looked HORRIBLE. The picture was blurry. I spent like 10 minutes converging it and it looked brand new when I was done. It's worth taking the time to adjust it right, sometimes that's all it needs!

Saw this thread and figured I'd jump in with an issue that is kinda-sorta related--

I picked up a Millipede this weekend and upon plugging it in the first thing I noticed was the TM202G monitor was extremely dim. Pulling off the back to address the issue I discovered the 10k ohm brightness adjustment was missing its center knob thing altogether (so no way to adjust). I've been online trying to locate a suitable replacement for it but nothing really matches up with the part number anywhere. Scoured Bob Roberts site, etc.

Scroll to PDF pages 54-55 for the video amplifier PCB
http://pdf.textfiles.com/manuals/ARCADE/SMALLFILENAME/tm202g.pdf

What I think it is (1/2 watt? doesn't seem to be mentioned)
http://www.mcmelectronics.com/product/28-493?scode=GS401&catargetid=530004080000291395&cadevice=c&gclid=CMq1xfn_r78CFU1qMgodoVkANw

Also looking at getting a cap kit to install so any advice for this particular monitor is mucho appreciated.

M

I can tell you this monitor drove me absolutely nuts! it's got so many fiddly adjustments and points of possible failure that I seriously considered replacing it. I'm glad I didn't, because even though I had to spend many hours adjusting everything (including the yoke), it has a gorgeous picture.

First thing to keep in mind is that the tubes on these are very hard to get replacements for, and are typically only found in ancient Panasonic TV's.
It has a uncommon neck socket so if you need a new tube, you may wish to just replace it all if you find your tube is bad.

Second, is the flyback replacements for these have some issues and have sometimes been known to cause damage to the chassis, specifically the focus potentiometer.... so my advice is don't replace the flyback unless you need to.
Cap kits are not available too many places for this model monitor, Bob Roberts and Arcadeshop are pretty much the only two I found with reasonable prices. I went with arcadeshop since I was already ordering a bunch of stuff there.

In my experience with mine I replaced the caps, reflowed all the RGB headers and board interconnect points. After that all I had to do was a bunch off fiddling with the adjustments to get it looking nice. Patience was the key here.

you could try finding someone with a scrap chassis and rob the potentiometer from it if you are worried that you won't be able to find a close enough replacement, they are often sold cheap by arcade hobbyists when the tubes go out (like I said new tubes can be hard to find) But the one you posted a link to looks compatible.

I recommend to do the cap kit and potentiometer and go from there. If you still have issues after that is done, I'd get the tube tested before moving forward with any further repairs.

Send Bob and e-mail he may have it and just doesn't have it listed on his site.

Bob replied this morning and said finding a clunker chassis to scavenge was the best bet so I'm working picking one of the two that are on eBay. Of the two choices there's a cheapie for $30 but man you gotta love it when someone uses the absolute sh*ttiest camera ever to take a picture of something they want to sell online.

This may be the world's most expensive 10k ohm potentiometer, ever.

Made an offer on the other "better photo" chassis and got it. Guess I'll order a new Millipede CPO and trackball replacement parts to keep myself occupied in the meantime.

i guess i don't understand exactly but why are you buying a dead chassis to get a 10k pot when they cost literally a dime?

LOL I do what Bob says. That particular pot is not available anymore per Bob. If you have a link to the same pot where it costs $.10 please feel free to share.

If you can measure the spacing of the holes I'll find you one.

Or you can just mount it anywhere you want an hook it up with wires instead of it being soldered directly to the board. Hey a 10K pot is a 10K pot no matter how you hook it up or where you mount it.

That's a really good idea.

hmmm i never thought monitor adjustments would be such a challenge to novice and experts alike!

story time, my two arcade operator and repair friends respectively could not figure out how to get the picture right with an odd game PCB. in the end they ended up telling me that it was a strange sync issue and my monitor just was not compatible. i thought i knew what it was but i didn't dare tell them what i thought as they tons more experience than i did. long story short after they left and i was alone i adjusted the horizontal sync and go the board to display perfectly.

i could tell you a hundred difficult things with arcade machines but adjusting the monitor comes so easy for me. i think it's all about having the "eye" as i do graphic design work.

It's possible your game isn't compatible, I have come across that issue with older games.

who me? like i said, i adjusted the monitor and it was in fact compatible. these operators are just not used to adjusting the H sync at all. i think once it is set right it works on any game you throw at it unless it is a bootleg