Sync issue with Rastan JAMMA

Tenn_pin

New member
Joined
Dec 28, 2008
Messages
101
Reaction score
0
Location
La Vergne, Tennessee
***Pictures are in my profile.*** I found this Rastan with a 20EZ with what seems to be a sync issue. I put a Superman board in the machine and it works great, so the problem is with the Rastan board. I have tested all of the traces on the board and found no problems. While the game is playing, I can see the features of the play, but there is a lot of pattern lines and colors that makes the screen look scrambled. The players man is also doubled on the screen at times with one being in the correct place on the screen and the semi-ghost image being on the right side (about 3 inches). Where do I start looking for issues?

Thanks,
R
 
Last edited:
Check the power. Some games need a little more power to the board. Super man may take 5 but wont hurt to try. I always start with the power. Then I adjust the monitor. Then I check wires, fuses, and grounds. That is the easy stuff :) And it works about 50% of the time. If that's not it try cleaning the edge of the board. If that's not it clean the legs on the roms. ... Good luck
 
Check the power. Some games need a little more power to the board. Super man may take 5 but wont hurt to try. I always start with the power. Then I adjust the monitor. Then I check wires, fuses, and grounds. That is the easy stuff :) And it works about 50% of the time. If that's not it try cleaning the edge of the board. If that's not it clean the legs on the roms. ... Good luck

+1 I've had a number of graphical issues similar to the ones described fixed by feeding the board just a tiny bit more voltage. By tiny I mean don't go over like 5.15, 5.2ish, just something small, you'd be surprised what a difference .03v can make. Some boards are thirstier than others in general, but I'd say check the +5 at the roms to see if there isn't some kind of drop going on between the edge connectors and the board components. If you've got it set for a flat +5 at the edge connector but the roms are only getting 4.95, than can cause issues like that. Not necessarily indicative of some major board issue, just the nature of a bit of voltage drop through complex circuitry, especially in electronics that have been used as long as arcade games have.

After that, yeah, wires, fuses and grounds, and double check to make sure the sync pin is connected to the right spot on the monitor. I'm not familiar with that monitor or game, but a Rastan manual can be found:

http://tamdb.net/index.php?page=Manuals&PHPSESSID=34a8cccfc7c382291bf69896585c5ec2&lettre=R

and the EZ monitor manual:

http://pdf.textfiles.com/manuals/ARCADE/S-Z/

Double check to see if the signal from the board is horizontal, vertical or composite sync and what pin it's going to on the monitor to make sure it matches. I'd read through them but I don't have the time at the moment. If you have issues getting it figured, post here and I'll read through them.

Probably a lot of this is stuff is things you've already tried, but better to be too complete in an answer than not complete enough. :) Hopefully a bit of a bump to the +5 is the solution or the sync pin is just hooked up to the wrong one.
 
Uh, did you at least try adjusting the holds? Not every board syncs at the exact same frequency....
 
Uh, did you at least try adjusting the holds? Not every board syncs at the exact same frequency....

*headbrick* Yeah, that'd also be a really easy bit of troubleshooting I missed, doh. Horizontal hold would be the route to go from the sound of the player doubled off to the right, wouldn't it? Someone please correct me if I'm wrong on that one, always good to have the right info for troubleshooting if I run into that in the future.
 
*headbrick* Yeah, that'd also be a really easy bit of troubleshooting I missed, doh. Horizontal hold would be the route to go from the sound of the player doubled off to the right, wouldn't it? Someone please correct me if I'm wrong on that one, always good to have the right info for troubleshooting if I run into that in the future.

From what I remember, he's tried adjusting the monitor for the Rastan board. He came by to borrow the Superman board, ... but when he returned it, didn't bring the Rastan board to test it out in our city cabs! Dangit, Cletus!

Seriously though, TennPin, next time you're by the mall, swing buy and we can slap the board in one of our city cabs to make sure there's not some weird jibberish coming out of it that the EZ20 can't understand.

(this is William BTW, the other one that's not Rob or Jason)
 
Thanks everyone

I have reseated all ROMS, adjusted voltage, checked pulses on the board, adjusted all pots for horizonal hold. Thanks for the Superman, William. I will make it back up to the arcade next week. This weekend, nephew is graduating from MTSU, corporate dinner Saturday, and family Christmas dinner at the farm in Giles Co. Pulling out my bald spot just thinking about it. I have not checked the sync diagram for the 20. Will do that this week.

Ghosts and Gobblins is a great game. I play it every morning before work and after Captain Fantastic. Still kicks my ass, but loads of fun to play.

Randel
 
Found the full manual for the monitor:

http://www.mikesarcade.com/arcade/monitors.html

Looking at the manual for Rastan and the manual for the monitor, it seems that both of them operate with negative sync. Neg sync being pin 6 on the r/g/b/sync section of monitor input. Assuming that the sync line is going to that pin, sounds like there's another issue going on. :(
 
You should try connecting it to another monitor if possible before dismissing the monitor or sync wiring...
 
I have checked the sync path from the monitor chassie board to the MPU board, through the MPU to the chip pin. Continuity was good.

5.12V out of the PS and 4.81V at the first test bump from the connector. Not sure why the drop off in voltage. Connector is clean, both male and female sides.

I will pull the chips and clean the legs. I have reseated them, but maybe some corrosion is there that I did not see.

Thanks for all of the replies. I will post a picture of the screen later this week.

Thanks,
R
 
This is where a logic probe or an oscilloscope will come in handy. You can look to see if you are getting the sync pulses out of the board. If not, back trace it to see where it stops so you know what part to replace.

RJ
 
Sorry for the delay

This work thing has AGAIN gotten in the way of the Hobby...

I will be taking the chips out and cleaning legs on Tuesday. Wife has a laundry list of s**t to do for the weekend. Good thing I am on vacation next week.

Is there a schematic for the board that tells what each chips function is?

Thanks,
R
 
Last edited:
Got Pictures

OK, so I am not the most proficcient PC user in the world. I cannot find how to upload pictures here, so if you can look in my profile, I posted 3 pictures of the issues I am having.

Thanks,
R
 
OK, so I am not the most proficcient PC user in the world. I cannot find how to upload pictures here, so if you can look in my profile, I posted 3 pictures of the issues I am having.

Thanks,
R

picture.php


picture.php


picture.php
 
BTW - the first two pics look like a board issue, not a monitor issue. The third picture just looks screwy....
 
The 3rd picture is where the board is not plugged into the machine. I need to reduce the red drive, which I believe will even out the color scheme and drop the red lines on the blank screen.


BTW, how did you get the pictures on the thread?

R
 
1) Right-click on the picture and select 'Copy Image"
2) In your reply box, click the image that looks like this:
insertimage.gif

3) Right click in the box that pops up and select 'Paste".
4) Click 'Okay'
5) Repeat as above for up to 5 different images
6) Click 'Submit Reply'.
 
Back
Top Bottom