QA Podcast – Episode 11
This episode of the podcast was recorded on Saturday, May 1. For more information on our live podcasts, please visit our BlogTalkRadio site at http://www.blogtalkradio.com/arcaderepairtips. When we are live you can talk to us on the air at (347) 633-9045. On this episode, Tim, Stan and I answered your questions regarding…
- A Street Fighter 2 with horizontal collapse
- A Mortal Kombat with an hourglass shaped picture
- A Donkey Kong with bleeding colors
- A Neo Geo Candy Cab with a dead monitor
- A Raiden 2 with a warped screen
- A Cal .50 with power supply issues
- A Q*Bert with a broken knocker
- A Neo Geo 1 Slot with a resetting issue
- A Mortal Kombat 2 with sprite issues
- Using the 8liners chassis on a TV tube
- Replacing a Donkey Kong Control Panel Overlay
- Converting a Super Pac to a Ms Pac Man
- And some general broken monitor troubleshooting.
We also go over some listener progress updates as well as some details on how arcade cabinets are constructed. Please feel free to leave any comments, questions or suggestions below. As always, you can contact us when we are off the air by email at questions@arcaderepairtips.com or by calling our voicemail line at (972) 8AR-TIPS or (972) 827-8477. Enjoy!
Stan “The Man” Bell has been an avid arcade collector for several years. He has worked on hundreds of arcade games and coin operated machines. He has also made significant contributions to several of our repair projects in the past.
Special thanks goes to [velvet] once again for allowing us to use their music in our content. Please check out their website at http://www.enjoyvelvet.com/ for more information.
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Hi guys,
Thank you for all the work you do to make this hobby more enjoyable for everyone! I’m a big fan of your website and your podcasts, and if my newborn twins give me a chance I’ll try (again) to reach you live via phone during the podcast.
I’m having a problem with a PacMan Plus that I purchased a while back. It was inoperative when I bought it, and I was unable to get any information from the previous owner as to its history. I was able to do some basic troubleshooting with a known good PacMan cabinet, and found that both the board and the monitor are bad. I swapped boards (I included the pac plus daughter board and swapped the entire unit together). I inadvertently further damaged a chip on the pacman plus board, so I’ll be sending that in to a repair service. However, its the monitor I’d like some help with.
The monitor displays a static image (which is at http://www.domoe.com/pacmanscreen.jpg). The bad board puts out random sprites from the game (on the known good pacman cabinet), so this is not the video signal coming from the board. The monitor is receiving 120VAC. Also, when power is applied to the monitor there is a high-pitched noise that is virtually inaudible but I’m pretty sure that if I kept the cabinet powered on for more than 5 minutes that I’d get a nosebleed and a throbbing headache. A visual inspection of the board shows no obvious damage. What could be causing this combination of issues with the monitor?
Thank you for any help you’re able to offer, and I’ll be listening to your future podcasts in hopes of hearing a reply.
Anthony
Oh, I forgot to mention that the monitor is a Wells Gardner 19k4616.
Anthony,
From the picture you sent and the way you described the issue, it sounds like the monitor is either not getting a video signal or is having some sync or voltage issues. The link that you provided really makes me lean more towards a lack of video signal. I would definitely check your harness connection from the board to the monitor. It could be that you are having some wiring problems here. Also, the board might not be receiving the correct voltage from the power supply. Try checking the voltage coming to the board from the harness with a multimeter. Obviously if your board is not getting power then you will not have anything on the screen. Also, looks like your brightness is a bit high and probably needs to be adjusted down.
If you have determined that the wiring is working and the board is getting power then you might want to try and adjust your sync and test your B+ voltage potentiometers on your monitor chassis. You might also check to make sure that your sync wires are coming into the correct pins on your chassis as this might also cause an issue. Adjust the sync and see if you can make out anything on your monitor. Also, be very careful when testing the B+ voltage as it can contain high voltages of AC voltage depending on this chassis. I would definitely save this as a last resort.
We have also featured your question on episode 12 of our Q&A podcast. Please listen to it for more of our thoughts on your question. Thank you for your question and good luck with your repair.
Hey guys,
Thanks a lot for featuring my question on this podcast. I just wanted to give you a quick follow up. I had the Mortal Kombat cabinet with the hula effect on the monitor. I took your advice and got a cap kit for the monitor for around $10. It came with almost all the caps, 19 total, except for one extremely large cap and 4 or 5 small caps. They were marked with which caps to replace on the board, so I suppose it’s the more commonly failed ones or something along those lines.
I discharged the monitor and removed the chasis thanks to your videos, replaced all the caps, put it back in and voila! Straight edges again. Here’s a before and after picture, and thanks again for your help!
http://overridex.net/files/mk-before-after.jpg
P.S. The color difference is just because I used a flash in the second picture.
-Dan
Update #2:
Hey guys, Dan again with the Mortal Kombat cabinet from episode 11. So after a week or so of it working well, I left it on for a while playing it, then went to have dinner and when I came back the monitor was blank, but the lights were still on… when I got closer I could hear a steady ‘pew.. pew.. pew.. pew..’ from the monitor as if it was almost starting up but then not and trying again. Looking at the chassis the fan was twitching in sync with the sound. I did some looking around and it sounded like it might be the flyback. One troubleshooting article for my monitor mentioned one particular resistor getting very hot if the flyback shorted, and sure enough, it was blistering hot.
I got a new flyback from Bob Roberts for $27 and put it in – all is well – so far! Now I mainly just have some cosmetic issues to fix on the cabinet.
I do have one more question for you guys. It’s a tougher one to describe and difficult to take a picture of. This has been happening since I got the cabinet, before and after the cap kit, before and after the new flyback. I get some noise in the picture either only on particular screens of the game, or it’s only noticeable on those screens. When I say noise, I mean sort of white dots/static. I notice it mostly towards the center of the picture. Any ideas what may cause it given when I’ve already changed? Since it’s only happening on particular screens maybe it’s something with the game board? Though it could just be that I notice it on particular color backgrounds… I’m not really sure.
Anyway, any suggestions would be appreciated.
Thanks,
-Dan
Dan,
The noise or static that you are describing could be caused by your chassis not being grounded. Make sure that both your chassis and monitor frame are grounded properly. This issue could also be caused by the game board. You might try plugging in a different JAMMA board to your cabinet to see if the same static still occurs. If you have a chance you might snap a picture of it and send it to us so we can see what you are talking about.
We have also featured your question on episode 13 of our Q&A podcast. Please listen to it for more of our thoughts on your question. Thank you for your question and good luck with your future repairs.