The 3rd video in the Arcade Repair 101 Series, here we go over the most common circuitry you'll find on CPU PCBs. We talk about binary notation, hex notation, RAMs, ROMs, address decoding and lots of other stuff. Enjoy!
7 years later and people like me stumble across your videos and gain so much from them. I’ve been looking for this sort of teaching for ages! And you’ll be helping people for many more years I’m sure. Thanks!
Words can't explain how I appreciate your videos I'm a bench tech that just started in the arcade industry and your videos are the best teacher I ever had. Thanks u so much for these it helps me understand and become a better tech in this field.
Hi Adam, I don't have word to express to appreciate you, the way explaining in your tutorial is highly great.the kind you having is visible in your face. Thank you so much. I wish your long live and your family.
I can't thank you enough for doing this series, never understood how common bus addressing with rom/ram worked till I watched this, looked through some schematics after this as well.
Love this entire series so much Adam!. Went through college learning to repair a lot of this stuff but your excellent videos simplify a lot of things & give invaluable shortcuts for the newbie tech & arcade game repairer. Can't wait to see you post more repair videos & hope you have been really well!
Dude, teach. Complex stuff briefed in just over an hour in a a really digestible manner and re-watchable? Top drawer. Thanks for my first insight into CPU stuff I have understood to a degree. Excellent and still relevant.
Great videos Adam. I think I've binge watched most now. You're a hero for Keeping these rare boards alive. I've learned so much from watching your videos, I think it might be time to find an old board and start having a go! Thanks for sharing a small part of your knowledge.
What great information and very well explained. I was looking for a book on how to get into arcade game repair/restoration and couldn’t find one, but this video answers a ton of entry level questions I had. Well done man!
This is amazing. Thanks so much. I've been looking for a clear explanation of this stuff, for years, and I'm so glad you've created these videos. More! More!
Awesome video! I have nothing to do with arcade games but at the moment I'm jumping into the deep end by repairing a classic Akai S900 sampler. It's fascinating how much these two kinds of devices have in common. It basically runs on a 8086 CPU with a multiplexed data/address bus but besides that I'm relatively certain I could run Donkey Kong on it. 😄 Thank you so much for this concentrated lesson on how these things work! ❤
Thanks for making these videos. I've only worked on board-level pinball repair- never on PCBs other than replacing sound section parts. Your thorough breakdown of a game's logic really gets me inspired to dig into a faulty board.
Awesome video, I've understood binary and basic logic for years but I learned a lot with this video as to how it all ties together with a CPU and memory. I even have a few non-working PCBs and after watching this vid I have a much clearer understanding of where in the circuit the problem is likely occurring. I'm excited to take a fresh look at those boards with my new understanding. I can't wait to see your next video as I know absolutely nothing about video logic and it's something I've wanted to know more about for a long time. Thanks again :)
Thank you so much for this video. I have an atari tempest machine that i just acquired and I have never work on this stuff before, By listening to your video and teaching i ave learn so much, I hope i can use this information to fix my game. Once again thank you. I will be watching more of your videos to educate my self some more.
It's hard to explain computer engineering stuff in 2 hours(i am a computer engineer too) for everyone to understand, but you done well! Thanks dude! This stuff helped me too, because I don't have experience in arcade boards, only fpga's and stuff from new technologies. Keep up the good work! I advice everyone to read more info about any of the topics, so they have a better understanding of what's going on, making their life more easier.
Loving these vids, keep teaching me. In my case your currently helping me fix some troubled retro pc's(memory address issues). After there done i wish to buy an arcade machine which can be quite expensive here in Australia, so a less then perfect fixers dream is what I'll likely end up with. Big thanks to you.
Hi Adam, excellent video. Speaking of video, I am so looking forward to the follow up on the video subsystem. This has always been a huge mystery to me. Cant quite get my head around the use of the PROMs for the colour palette. Anyway keep up the great work. It is very much appreciated.
Thank you for another great info filled video. This old arcade noob is slowly leveling up arcade knowledge. I can't wait for the video repair tutorial.
My brain is mush, but great video. I understood most of it. Next time you do a video with John's Arcade I'll have a better idea of what you guys are talking about. I plan on buying an arcade cabinet and want to learn prior how to troubleshoot/fix any issues that might happen. Thank you so much!!!!
I wish my teacher explaned the things like you do in this video. You should consider teaching as a profession ;-) Thanks Adam, its very interesting and informative ! Cant wait for the follow up video !
thankyou for the video ive been looking for video game circuitry info for a long time its not really found anywhere I cant wait to see more glad i found ur video, can u recomend any theory referances thanks again
Awesome video! I now know how to probe these ic's. I hope you can do a video using the Fluke 9010A as I would very much like to learn how to use that machine and there is no videos on it. Thank you again for this video it really helps me understand things more clearly.
Nice work Adam :-) Can you cover clocks at the start of the next video please (and the use of flip flops to divide the clocks down ? - I've seen lots of 74x74's fail - Oh and also the reset circuity which kick starts the cpu ? - no reset, no worky ) - One thing I have done in the past with hard to read schematics is to print them off and color them in using highlighter pens and sharpies (or screen shot and use paint or whatever as a rough overview), I tend to do the various buses in different colors so you can instantly see what devices are plugged in to the circuits and where.... then if I hit on a problem its easier to follow around... Had Bus Contention on a friends Tron recently, but working remotely together, James seem to have mostly nailed the issues now since posting below. Used a fluke 9010a and an analog scope synced to the chip enables to probe around,
Oh, and suggestion: I'd like to see videos on some circuitry basics, such as the role/types of resistors, capacitors, differences between grounds, etc. How they work in reality, why they are there, how to test for failures. Thanks.
I am trying to repair a Falcon Crazy Kong Pt2 and this will be a big help. I have two problems that could be related. Kong is just thin lines at the top and the game sprites only show at the very bottom part of the screen. It was working until I removed the PCB to work on my cabinet and then when I put it back it had these problems. I have checked the GFX eproms, replaced the 2114 and 5101 ram chips (one had a bad track and pad under) and also looked at quite a few logic sections around them, but so far not found the cause of the fault. My board has 2 sprite buffer ram ships and the schematic shows 4 so I am not 100% how this works, but I am about to use my usb logic probe and after watching this I have a better understanding of how everything works.
Amazing second video Adam, this is the area i've been having most issues with (address decoding). There's a lot of things i've picked up real quick after your first video in this series. Do you happen to have a good clean scan of a TRON manual? The ones in the usual places are a bit fuzzy on the CPU board around the H signals. I've got a board where it will read ROMs but won't read/write RAMs - keeps returning $FF all the time. Thanks again for the series.
Check that enable to the RAM! ;) It may be disabled all the time. I don't have a scan of TRON unfortunately. But I agree... all Midway schematics are such a pain to read in fact. Long live Nintendo! :D
OneCircuit That helped, thanks to help from a friend telling me how to use my scope properly. I had one channel on the scope on /CS and another watching the data lines - turned out to be a broken trace between the main databus 245 and the RAM 245. I found a better scan which i'll share with anyone who needs it just by accident. Board now gets as far as cross-hatch screen but stops - investigation continues.....
Great info. With logic probe you mighty find bad low or fixed signal, is idea of logic pulser that you fix that signal high, & game pcb works as long as you pulse problem area. or ...that's guess, can you explain logic pulser tool
genio!, como estas, soy pablo desd argentina. gracias por los videos, me cuesta seguirte un poco porque no hablo muy bien ingles. igual me sirve mucho, especialmente los graficos en la pizarra. un abrazo
