I just picked up a DD PCB. Was sold as working, but sadly seems to have a lot of errors. I’m fascinated by this video and will be following your tips to get mine working again. Thank you so much!
Thank you for you comment! Happy that you liked my repair video! I actually plan to release more repair videos soon. Next one should be another double dragon and also a Indiana Jones Temple of Doom Atari System 1 repair.
2 года назад
Hi, I just discovered your channel and I really like it. I also repair boards (but I speak french in my videos), and I learn lots of useful stuff watching your videos. I have repaired several bootleg boards, and I never have access to the schematics. They seem a huge help to avoid or speed up reverse engineering. Thanks for sharing your work!
They really are. Working on bootlegs or without schematics is possible but much more challenging.
2 года назад
@@christophzett I am currently working on a Thunder Hoop and the only schemamatics I have are in MAME's source code 😀. MAME is really helpful by the way!
I just wanted to tell you that your videos were fantastic. They really helped me. I have subscribed and look forward to any other videos you release. Thank you!!!
It is a logic probe and it shows if a ttl signal is high, low, pulsing or floating, It's sort of a poor mans oscilloscope - but it is really useful because you can check a signal line in a the blink of an eye. If you need to really know the details regarding a signal an oscilloscope will still be necessary.
arcade games ROM chips only use 11 address lines but the RAM chips use 16 address lines, why is that? Any reasons why the checksum to test the ROM chips is only 16bit checksum and not 8bit or 32bit checksum?
great video .. can you please explain what the other board here is..? is it a generic SYSTEM board? that the ROM PCB plugs into ? and were all games requiring this System board also ? and can we have more info on these system boards required to run these game boards..
hi great videos i have a problem on a double dragon bootleg pcb , stuck on rom check screen their is no 63701 check at all? any idea where to start as iam really stuck.
When I remember right the 63701 is the co processor for the characters, right? Well if it is stuck on this screen then I guess roms, the 63701 itself or the ram chip next to the roms are usual suspects. Checking the roms in an eprom programmer would be the first step I guess.
Hi a need help a have 6 games dont work if a switz the game on there is no pic or sound only blue screen please if you czn help me dubble dragon / street fighter 2 dont no the ader games
Hey man, I'm not sure you'll ever read this considering it's a rather old video but I have an issue with a DD pcb and I was wondering if you could help: The backdroung is completely messed up. All the sprites are perfect (characters, weapons, barrels) and so is the sound. But the background is a mess. i.imgur.com/zzbfXrb.jpg I've tried to study the schematics but it's really complex and I'm not sure where to look at. Can you pinpoint me to the right direction? (I'm equipped with a logic probe)
I sure try to read all the comments even if the videos are older. Well I'd say judging from the picture you provided there is at least 2 problems with the background tiles circuit. Some background tiles look fine. But firstly some tiles seem to have messed up colors while showing the basic graphical data that they were supposed to. And Secondly some tiles seem to contain the wrong type of graphical data all together. There is probably an issue with the back pcb. First thing I would do is remove socketed Eproms IC77, IC78, IC108, and IC109, clean them and reseat them. See if that changes anything. Second thing I would do is test them in an eprom reader agains the mame roms to see if their data is corrupt. Maybe try that and if you want you can get back to me and I can try to help further. ;-)
@@christophzett thanks so much, I'll try as soon as I'm back home from holidays. Since then I've seen your other video (where you show a mapping of each chips and what part they act on) and it helped me incredibly in understanding how the pcb works. Thanks again for your amazing work and I'll get back to you as soon as I can.
@@christophzett hey man, I'm back from holidays and back at it. I've tested the 4 background eproms. All tested good against their Mame counterpart. I've tried using a logic probe I've bought a while ago, but it was a first price I bought on AliExpress. My readings were odds to say the least. All outputs were high. On all 4 chips. Compared to pulsing on other eproms. But my probe is so low quality that it might not mean anything. I have checked all my traces and couldnt find anything wrong. Some rams definitely feels corroded but it's true for everywhere on the board. Not sure what to try next. I might get a better idea with my oscilloscope on those eproms.
@@christophzett so today I tested all the background eproms with my oscilloscope and the only thing I could find was that pin 23 (A11) didn't seem to receive a logic signal (blank signal). I've traced it to IC 38 and 58 (Ram I guess) and I indeed had a bank signal on the output (pin 19) and a signal in the input (pin 18). I thought I had my culprit but after swapping ic 38 nothing changed at all... So I'm stuck again. Any idea?
@@Mod_In_France Does the scrambled background look exactly the same every time you reboot the game or might there be some randomness to it? If yes that could mean that there is indeed a problem with a ram chip that holds the information for the background tiles.
You're like an arcade Louis Rossmann. I love that this is step-by-step. Helps arcade newbies like myself!
Thank you, great compliment. Wish you good luck with your repairs.
I just picked up a DD PCB. Was sold as working, but sadly seems to have a lot of errors. I’m fascinated by this video and will be following your tips to get mine working again. Thank you so much!
Nice work. Great problem solving and trace repairs.
Just found your channel. I really enjoyed this full troubleshooting walkthrough from ebay purchase to fixed. Please keep up the good work!
Thank you very much! Please check out my other vids!
Great video! I'd love to see more arcade PCB repair, particularly troubleshooting them with the logic probe.
Thank you for you comment! Happy that you liked my repair video! I actually plan to release more repair videos soon. Next one should be another double dragon and also a Indiana Jones Temple of Doom Atari System 1 repair.
Hi, I just discovered your channel and I really like it. I also repair boards (but I speak french in my videos), and I learn lots of useful stuff watching your videos. I have repaired several bootleg boards, and I never have access to the schematics. They seem a huge help to avoid or speed up reverse engineering.
Thanks for sharing your work!
They really are. Working on bootlegs or without schematics is possible but much more challenging.
@@christophzett I am currently working on a Thunder Hoop and the only schemamatics I have are in MAME's source code 😀.
MAME is really helpful by the way!
I just wanted to tell you that your videos were fantastic. They really helped me. I have subscribed and look forward to any other videos you release. Thank you!!!
Thank you very much! Next video coming soon I hope. It will either be another double dragon or a road runner atari pcb.
Work of determination :-)
Thank you very much!
Excellent video and top Mark's for your repairs very nice and clean, fantastic 👍👍👍
Very inspiring video, thanks. Love to get my hands on one of these arcade machines one day
Just supported your channel
Awesome repair 🙂
Juste for my knowledge, the light pen you use is working like an oscilloscope?
It is a logic probe and it shows if a ttl signal is high, low, pulsing or floating, It's sort of a poor mans oscilloscope - but it is really useful because you can check a signal line in a the blink of an eye. If you need to really know the details regarding a signal an oscilloscope will still be necessary.
@@christophzett Thanks a lot for your answer :)
arcade games ROM chips only use 11 address lines but the RAM chips use 16 address lines, why is that? Any reasons why the checksum to test the ROM chips is only 16bit checksum and not 8bit or 32bit checksum?
great video .. can you please explain what the other board here is..? is it a generic SYSTEM board? that the ROM PCB plugs into ? and were all games requiring this System board also ? and can we have more info on these system boards required to run these game boards..
mouse piss is what causes problems and having the pcb on the bottom of the cabinet. makes a good home for mouse lol
Would anyone know why my boot logo is half missing and characters are also missing. I have tried the options in this video with no luck
hi great videos i have a problem on a double dragon bootleg pcb , stuck on rom check screen their is no 63701 check at all? any idea where to start as iam really stuck.
When I remember right the 63701 is the co processor for the characters, right? Well if it is stuck on this screen then I guess roms, the 63701 itself or the ram chip next to the roms are usual suspects. Checking the roms in an eprom programmer would be the first step I guess.
Ok :-)
You dont need fluke 9010a
I like your video good explain
Hey I have an X-Men vs street fighter but the volume was too loud and when the technician turned it down the whole graphic messed up can it be fixed?
I have the same problem but.. not ur solution... pin 39 of cpu al time off.. what could else make garbage image ?
Awesome insight! Thanks for the video. =)
Hi great video do you know where I can get schematic for Street Fighter arcade pcb
There are really dozens of different streetfighter versions. I'd say just do a google search or try klov.com.
doktorzett thank you for replying
Hey please help I have a really weird arcade pcb. It says it’s royal bonus 2
Please please help
Hi a need help a have 6 games dont work if a switz the game on there is no pic or sound only blue screen please if you czn help me dubble dragon / street fighter 2 dont no the ader games
Hey man, I'm not sure you'll ever read this considering it's a rather old video but I have an issue with a DD pcb and I was wondering if you could help:
The backdroung is completely messed up. All the sprites are perfect (characters, weapons, barrels) and so is the sound. But the background is a mess. i.imgur.com/zzbfXrb.jpg
I've tried to study the schematics but it's really complex and I'm not sure where to look at.
Can you pinpoint me to the right direction? (I'm equipped with a logic probe)
I sure try to read all the comments even if the videos are older.
Well I'd say judging from the picture you provided there is at least 2 problems with the background tiles circuit. Some background tiles look fine. But firstly some tiles seem to have messed up colors while showing the basic graphical data that they were supposed to. And Secondly some tiles seem to contain the wrong type of graphical data all together.
There is probably an issue with the back pcb. First thing I would do is remove socketed Eproms IC77, IC78, IC108, and IC109, clean them and reseat them. See if that changes anything. Second thing I would do is test them in an eprom reader agains the mame roms to see if their data is corrupt. Maybe try that and if you want you can get back to me and I can try to help further. ;-)
@@christophzett thanks so much, I'll try as soon as I'm back home from holidays. Since then I've seen your other video (where you show a mapping of each chips and what part they act on) and it helped me incredibly in understanding how the pcb works. Thanks again for your amazing work and I'll get back to you as soon as I can.
@@christophzett hey man, I'm back from holidays and back at it. I've tested the 4 background eproms. All tested good against their Mame counterpart.
I've tried using a logic probe I've bought a while ago, but it was a first price I bought on AliExpress. My readings were odds to say the least. All outputs were high. On all 4 chips. Compared to pulsing on other eproms. But my probe is so low quality that it might not mean anything.
I have checked all my traces and couldnt find anything wrong. Some rams definitely feels corroded but it's true for everywhere on the board.
Not sure what to try next. I might get a better idea with my oscilloscope on those eproms.
@@christophzett so today I tested all the background eproms with my oscilloscope and the only thing I could find was that pin 23 (A11) didn't seem to receive a logic signal (blank signal). I've traced it to IC 38 and 58 (Ram I guess) and I indeed had a bank signal on the output (pin 19) and a signal in the input (pin 18).
I thought I had my culprit but after swapping ic 38 nothing changed at all...
So I'm stuck again. Any idea?
@@Mod_In_France Does the scrambled background look exactly the same every time you reboot the game or might there be some randomness to it? If yes that could mean that there is indeed a problem with a ram chip that holds the information for the background tiles.
I need to sent you some of my stuff to be recap
hello friend first of all excellent video, I have the same game but with different fails, I hope you could help me I hope your answer greetings
Hi
Were are you.?
You are dead? :-)
Why you dont make videos?
We want VIDEO
No I am okay, thank you - more vids coming soon, next one will probably be a centipede pcb repair
doktorzett
Its a joke.
We waiting for your great video
Regards