GO7 rolls horizontally

KRJMN

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So my GO7 screen is slowly rolling horizontally and I can't seem to make it stop with the adjustment controls. Any tips on what to check?
 
from how I've seen guys respond to this problem before.........

it depends on which game you are using it in. probably a sync issue.

get us some more information, and I am sure someone will come in a solve your problem.
 
did it just start doing this or is this a new game your go7 is in? you could try reflowing the headers pins. one of the pots might be going bad, you can try reflowing them too. i would try that first.
 
Yeah, it just started doing it one day. It's an old centipede machine and namco classics 2 is the game in it. I bought it a year ago and it was looking ok untill a few months ago. I have not changed the game or really done anything to it. I first noticed a problem in the screen during the attract mode. It flips through all the different games to show what they look like, and the screen would flick and then roll once when the picture changed for each game. Then one day it just started to roll at random when the game is being played.
 
No. I haven't done a thing to it since I bought it. I was hoping I wouldn't have too. I'm sure a cap kit would be good for it though, the colors on the screen are looking pretty dull and faded. It took me NINE HOURS to do a cap kit on my sanyo. I am not super excited to have to the same to this one now.
 
No. I haven't done a thing to it since I bought it. I was hoping I wouldn't have too. I'm sure a cap kit would be good for it though, the colors on the screen are looking pretty dull and faded. It took me NINE HOURS to do a cap kit on my sanyo. I am not super excited to have to the same to this one now.

The G07 is much easier to cap than a Sanyo, but 9 hours is outrageous unless you have lots of interruptions. Even an unskilled solderer should be able to remove one old cap and install a new cap within 5 minutes. Considering a G07 only has 17 caps (if you do the curl modification), that means you should have it done within an hour and a half. A full Sanyo cap kit doesn't have much more caps than that, so it should take about the same amount of time - unless you tried to do it without pulling the entire chassis (and maybe monitor) out of the cab to do it on the bench/table. Experienced monitor techs can do cap replacements in under a minute, and can cap a G07 in 15 minutes.

Of course if you cap a G07, it is recommended that you replace the flyback as well - and that can take a little longer to do (less than 30 minutes for the noobs). It's best to get a G07 Deluxe Rebuild Kit from Bob Roberts and install everything in it, or pay someone to do it for you...
 
Well maybe it wasn't quite nine hours, but it felt like it. It wasn't the soldering that took so long it was me searching the board to find the space for each cap. It was my first attempt so I was very paranoid about accidently putting somthing in the wrong way, so I was going super slow as a precaution. Its interesting to hear your work time estimates. I guess I need to get the lead out! Well you've convinced me to do the cap kit, and to not be such a paranoid freak, thanks.
 
If you don't feel like doing it, I'll rebuild your G07 for $80 shipped.

If you do feel like doing it, MAKE SURE YOU CHANGE OUT THE ORIGINAL FLYBACK.
 
Did you ever resolve this? My centipede has been doing this for a while as well. It won't hold. Rolls left and right. Going to pull the chassis and check out X301 & X305. May have a IC501 (HA11244) to swap in not sure of my stock on those. Need to check if I even have any 2SC1685's. Need to finally fix this roll problem. I'd run a cap kit long ago that did not fix this.
 
Did you ever resolve this? My centipede has been doing this for a while as well. It won't hold. Rolls left and right. Going to pull the chassis and check out X301 & X305. May have a IC501 (HA11244) to swap in not sure of my stock on those. Need to check if I even have any 2SC1685's. Need to finally fix this roll problem. I'd run a cap kit long ago that did not fix this.

if you are using negative sync be sure that R314/317 are 390 ohm.

if they are not your pic will role and you will not be able to stop it.
or it will stop for a few and start again.

Peace
Buffett
 
Looking over the schematics - is there any reason they would not be 390 Ohms? Shows clearly that they are. I guess I could see what my supply of 390 Ohm 1/4w resistors is looking like and replace them.

I guess it would be Horizontal sync since the monitor is mounted sideways.
 
post a pic of the screen.

for some reason the factory put the wrong value resistors on the chassis.
why they worked for all theses years with the wrong value knows.

i have change many of them over the years.

your problem may be something different, we need a pic to see.

Peace
Buffett
 
I have pulled the Dragon's Lair G07 chassis for probably the last time. It's teasing me - I get it to work - then it fritzes out. After I got burnt on that yesterday, I recapped another G07 and fired up Bank Panic. So that one's good to go. Today I planned on recapping another and try to get RB Tapper fired up. I've already got Centipede pulled out with a mirror in front of it, so I may be able to pull that chassis and get some pics and a good look at it today.
The only one that's ever rolled like that with absolutely no attempts to lock in is Centipede. I hope your right.
 
Nearly every time I've experienced sync issues on a G07 that has already been recapped, it was due to cracked solder joints on the sync input headers. It's so common on the G07's that it's the first thing I ask an owner to do when they call me with a rolling picture:

"tug on the video input wires lightly and tell me what happens....oh really? The image locked in for a sec? Well great, here's what you have to do......."

LOL
 
I have had multiple sync issues with multiple Centipede's before. I'm not sure what the hell it is with me and Centipede but i don't care if I ever work on another one again.

For mine, this was a pcb issue and not a monitor issue. It seems that sometimes the positive sync circuit becomes unstable and I have to switch to the negative sync option. Centipede supports both positive and negative sync.

What I've done, is re-pin the edge connector for the opposite sync than what you are trying. If you have a roll with positive sync, wire it for negative and see if it works. I remember Brzezicki (the Centipede guru) telling me that he has some Centipede boards that have corrupted sync circuits like mine.

Anyway, maybe this can help?
 
I have had multiple sync issues with multiple Centipede's before. I'm not sure what the hell it is with me and Centipede but i don't care if I ever work on another one again.

For mine, this was a pcb issue and not a monitor issue. It seems that sometimes the positive sync circuit becomes unstable and I have to switch to the negative sync option. Centipede supports both positive and negative sync.

What I've done, is re-pin the edge connector for the opposite sync than what you are trying. If you have a roll with positive sync, wire it for negative and see if it works. I remember Brzezicki (the Centipede guru) telling me that he has some Centipede boards that have corrupted sync circuits like mine.

Anyway, maybe this can help?

Well maybe I'm just dumb when it comes to Centipede, but I didn't even know you could switch to positive or negative sync. Where is this said switch at? I really do not want to repin my edge connector.
The sync circuits look to me to be controlled by about 4 transistors on the chassis, excluding those 390 Ohm resistors I need to look for. Give me the end of today and I'll snap a shot or two. Seems friggin weird that Centipede is as widespread with this problem.
 
I have had multiple sync issues with multiple Centipede's before. I'm not sure what the hell it is with me and Centipede but i don't care if I ever work on another one again.

For mine, this was a pcb issue and not a monitor issue. It seems that sometimes the positive sync circuit becomes unstable and I have to switch to the negative sync option. Centipede supports both positive and negative sync.

What I've done, is re-pin the edge connector for the opposite sync than what you are trying. If you have a roll with positive sync, wire it for negative and see if it works. I remember Brzezicki (the Centipede guru) telling me that he has some Centipede boards that have corrupted sync circuits like mine.

Anyway, maybe this can help?

I had a very similar problem with my Centipede which I thought was the G07. I recapped the G07 and the problem remained. It turned out to be a problem with the Centipede PCB which I never resolved. I picked up another Centipede PCB and the problem went away.
 
Well maybe I'm just dumb when it comes to Centipede, but I didn't even know you could switch to positive or negative sync. Where is this said switch at? I really do not want to repin my edge connector.
The sync circuits look to me to be controlled by about 4 transistors on the chassis, excluding those 390 Ohm resistors I need to look for. Give me the end of today and I'll snap a shot or two. Seems friggin weird that Centipede is as widespread with this problem.


From what I remember, it is just one pin on the edge connector to re-do. Look at the schematic and you can see where it is. Put in a new pin to the edge connector and then run that wire to the negative (or positive, whichever is opposite from the one not currently working) sync pin on your G07 and disconnect the positive plug going into the G07. It really is easy to do and can just be done quickly to test if this is your issue.
 
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