Sega Rally - screen problem

@Parris, Here is a photo of the cab on the day I got it. As you see the screen was not too bad then, just a little annoying. 3 days in almost half the screen was gone.

It was meant as a restoration project for the summer, did't think the job would be this big.
That's my Jamma/MAME cab next to it, The one I replaced the old monitor with a CRT TV. Its a real light-weight compared to Sega Rally.

At this stage I like the idea of getting the board repaired by someone with plenty of experience with this job. Any place you can recommend. I could even post the board to America if needed.

 

The monitor chassis? Well, I could do it, but unfortunately I don't have a tube to test it on, so it would be a question of doing the cap job, testing the vertical output chip and resistor as best I could and replacing if necessary, and hoping for the best! I don't fancy powering up without a tube, really!

As it is a Sega, you could try Andy Geezer at Segashed. There are a few techy based guys up your way on the Jamma+ forum, such as yorkshire_spam, but I know he's a busy man. Likewise with Ordyne (giz10p.co.uk) but you could try. LukeWells is in Lancs. If it were a Hanty, you could have got them to sort it.

 

I have just arranged to get a whole working replacement from Videotronics. Their just down the road from me.
I'll use the chassis from that on my installed tube and have a go at the capkit on the old chassis later.

 

Mo in Bradford isn't it?

 

That's the bloke.

 

You mean the eBay user Videotronic Suk? Oh sorry, that's Videotronics UK :110:

Well don't forget to discharge your chassis first! In fact, discharge them both.

 

LOL - he's got a bit of a tainted reputation that fella from all the posts I have ever seen mentioning his name. If I were you I'd go down, ask him to test anything in front of you and make sure it's all 100% before leaving.

The only item I have ever purchased from him was Naomi cart and frankly there was nothing wrong with it, but I've heard others complain bitterly and slag him off endlessly.

 

On that discharge issue being discussed here earlier. I went to see my mate (35 years in the TV business) and as we were chatting I watched him discharge an ordinary TV by getting a flat screwdriver, putting it under the rubber cap until it touched a terminal, then used another screwdriver touching the first and off to the frame. A small crackle later he pulled the whole thing apart without dying...

He laughed when I mentioned soldering stuff together, but he then said 'It's actually pretty dangerous... not enough to kill you.... but it could cause a heart attack or a stroke, so....'

 

Yeah, a lot of TV repairmen used 2 screwdrivers. Personally, I wouldn't recommend that (unless you're really confident you won't slip!), but he's not the only person who does that certainly.

I asked Randy Fromm (who had an arcade school - very experienced guy) about the leaving the cab plugged in vs unplugging. Here's his answer:

The outcome of Parris talking to his engineer friend, me talking to my engineer friends and Randy Fromm's opinion seems to be one common factor that's agreed on: you DON'T discharge to ground but to the monitor cage. Whether you use an HT probe, (properly made up) screwdriver/wire combo or the two screwdriver method is your choice, but there's no reason for the cab to be left plugged in to keep it earthed. In fact, Randy pointed out that Americans don't use the redundant switch and called it an odd UK custom as everything that needs a switch has a switch on it. In that case, if your cab doesn't have a switch in America, there's no easy way to leave it plugged in WITHOUT power flowing surely? So you'd HAVE to discharge that cab without it being plugged in!

*EDIT*

Bob Roberts (another respected ex-arcade tech with many years' experience) updated his page to reference this, too:

http://www.therealbobroberts.net/sb.html

Long story short, he said the same as Randy. It has nothing to do with ground and therefore you don't need to earth your cab.

 

I have seen the "two screwdriver" method on youtube. Looks crazy to me. I think I'll go for the single with a well connected wire and a strong clip on the end.

I am just waiting to find out what days I am working next week, Then I will arrange to collect the monitor, I'll also ask if I can see it working before handing over the cash.

 

IT LIVES, and more importantly so do I. I've got the hang of discharging now.

Got the replacement screen from VideotronicsUK. It was removed from a working Daytona USA cab. I saw it running from cold for about 5 minutes and powers off smoothly with no signs of a bad flyback.

Installed it in my cab (tube and all) and the picture is brighter, cleaner and has no sign of any interference noise like the old one had.
I still get a small amount of screen folding at the top of the screen but I must put this down to the game its self as I saw Daytona working fine. Anyway it doesn't ruin the game at all.

The only annoying thing now is that I can't adjust the screen width (H.Size). Its a large copper wound barrel in the front panel. I have carefully turned it with a plastic key but the width stays the same.
How far should I turn this? Its hard to see under the screen, and I don't want to brake my new setup.

 

Did we determine the monitor for sure?

There should be a bunch of potentiometers somewhere - either on the chassis or there will be a remote board. One of those will do H Size. Do V Size and you should get rid of whatever's at the top, too.

The two screwdriver method is quite dangerous as it means putting both hands in the cab. If you accidentally touch something, that increases the chance of a shock across the heart.

 

How would the game cause screen folding? Sounds a bit suspicious to me

 

Well the monitor and chassis were working great in the Daytona cab it came from. As soon as it went into mine the top inch is folded, just like the old one did.
its not the settings, I went through them again.
If its not my game board (which I also doubt) then could it be the cabinet power system not giving enough power the the monitor?
I have no other games to test with.

Anyway, it plays great and the new tube has no screen burn at all. I got the picture h.size done. I just needed to keep turning the coil 8/9 times, its not as sensitive as the other small adjusters.

 

Ask on a forum such as Jamma+ or ArcadeOtaku - there may be a local who'd pop round with a board.

 

Unplug the video cable to the monitor board, turn up the screen brightness (using the knob under the focus) so that the screen turns a light grey, if the screen looks weird at the top (ie it's not grey but black) then it could be a transformer issue (unlikely but it's possible), turn off the machine, plug the video cable back in and see what the top of the screen looks like when the games running.

If you've replaced the whole chassis board and CRT then it's unlikely to be a monitor issue and screen folding doesn't sound like a game board fault. Unplug the degausing loop and see if that makes any difference.

 

Just tried all that. The screen turns grey with a few lines moving vertically down the screen. That area at the top stays black.
unplugging the degaussing loop makes no difference I can see.
Do you think its more likely power related than something like the filter-board?

I got registered at Jamma+ so I'll see what they think.

Thanks for the help on this so far, its appreciated.

 

There should be a noise filter unit in the machine, bypass this and see if it gets rid of your problem.

 

You mean a AC line filter? I think there is one in the bottom of the cab, I'll try that next

 

Any more luck or does the silence mean that you zapped yourself and are currently pushing up daisies?