Subject: Dragon Breed M72 color repair log
Posted: 07 April 2015 at 9:27am
Nice one :D]]>
Subject: Dragon Breed M72 color repair log
Posted: 06 April 2015 at 12:26am
Fun game too
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Subject: Dragon Breed M72 color repair log
Posted: 05 April 2015 at 5:29pm
Nice repair
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Subject: Dragon Breed M72 color repair log
Posted: 05 April 2015 at 4:55pm
A friend of mine had a color problem with his Dragon Breed M72 board.
The image was too reddish with greens barely visible (it was more visible on the screen than on this screenshot):
Checking the RGB outputs on the Jamma connector with the scope showed that the green pin had a much weaker signal than the red and blue pins.
I retraced the green pin from the jamma connector to pin 3 of a 74LS38 (IC67) and a resistor network (RA14) on the main board. The red and blue pins were also connected to the same 74LS38 (pins 8 and 11) and to independent resistor networks (RA13 & RA15).
74LS38 is a quad 2-input NAND buffer with open-collector outputs and pins 3, 8 and 11 are outputs.
Checking the output signals on the 74LS38 showed a similar signal on pins 8 and 11 (red and blue) but a weaker signal on pin 3 (green).
I replaced the 74LS38. The signal on pin 3 looked then the same than pins 8 and 11 and the colors were back to the normal with a good balance on screen:
Edited by Yves M - 05 April 2015 at 4:56pm]]>
Subject: Taito F3 mother board sound repair log
Posted: 05 April 2015 at 4:12pm
I got a Taito F3 mother board that got sound only sometimes.
It was not a volume or scratchy sound problem. When the sound was playing, it played perfectly but it was only playing for a few seconds during intros or in game then it disappeared instantly within a few seconds...
I noticed that the sound could appear magically when starting a new game or passing to a new screen or level in game (only for a few seconds then disappeared suddenly).
I tried to bend the board with no results having the sound back but when I could get the sound running, touching the board made it instantly disappearing.
It was clearly a bad contact somewhere... Also, due to the way the sound was "appearing" and "disappearing" I focused looking at the sound generating part and not the amplifying system.
After a few hours of looking at the PCB with no results (there was a broken trace on the solder side but repairing it didn't change anything), I finally found that the pin #24 on the Ensoniq OTISR2 chip located at IC26 looked like to have less solder on the parts side than the other pins.
That was simply a bad solder joint as I reflowed it and the sound worked perfectly then !
Edited by Yves M - 05 April 2015 at 5:15pm]]>
Subject: Konami Devastators Repair Log
Posted: 03 April 2015 at 4:48pm
Hi there,
I I had a devastators board that was doing this:
The sound was fine, and the game plays as normal. The tiles all looked messed up, and there was some static corruption on top of the moving background graphics.
First, I pulled the EPROMs and found that the tile EROMs were all bad. I replaced them with new chips, freshly flashed. The image was better, but some corruption remained. After probing around the tile processors, I found that two address lines on the Konami 52109 custom chip were floating:
I ordered a replacement chip from mikesarcade.com, and some Chipquik. Chipquik is an alloy with a really low melting point (around 60C). You run it down each edge of a surface mounted chip, and it mixes with the existing solder. You can then heat up the alloy on all four edges, and it stays melted for a really long time. You can then just pick up the chip using some Blutack stuck to the end of a screw driver.
Finally, I soldered in the new chip. I used lots of liquid flux, and very little solder, and it went in easily. Any excess solder I removed with a little solder wick. Fitting the chip was much easier than I'd feared. It was my first attempt at replacing an SMD component, and it went very smoothly! The EEVBlog tutorials on youtube were really helpful (#186 and #437). I used the drag method described in the EEVBlog blog video #186.
Once the chip was replaced, it looked like this:
Finally, the total board, after fixing up the EPROM labels:
Now the game runs perfectly:
I'm starting to get the hang of these repairs now! Next I'm going to see if I can figure out how to convert a Taito Football Champ into something else.
Subject: Taito Bubble Bobble Repair Log
Posted: 31 March 2015 at 12:47am
lol yea twas hoping to just sub in the other video board from the second bootleg but when I got it I noticed they are slightly different and I'm unsure you can just plug-n-play do different video boards fromm to different bootlegs - wish I had pinouts for the 60pin connector the joins the cpu to the video pcb but alas can't find them especially for two different bootlegs :-(]]>
Subject: Taito Bubble Bobble Repair Log
Posted: 30 March 2015 at 11:00pm
Have you read the aussie arcade fix log?
http://wiki.aussiearcade.com.au/index.php/PCB_Repair_Logs_Bubble_Bobble
Hope the link works as I am using my phone atm. Third time is the charm lol it is for an original pcb but most boots are pretty much identical
- Ben
Edited by ben76 - 30 March 2015 at 11:02pm]]>
Subject: Taito Bubble Bobble Repair Log
Posted: 30 March 2015 at 10:34pm
Well, I purchased another BB bootleg that has some issues aswell, anyone interested in taking over this project? someone that can also do the REDUX upgrade - can keep one of the boards as partial payment - thanks in advance]]>
Subject: Taito Bubble Bobble Repair Log
Posted: 12 March 2015 at 2:38am
???????????????????????????]]>
Subject: Taito Bubble Bobble Repair Log
Posted: 11 March 2015 at 2:13am
had a thought :-) I had this same problem before and after I resoldered a clearly broken pin-11 on LS374 at IC97, this should narrow it down, shouldn't it?]]>
Subject: Taito Bubble Bobble Repair Log
Posted: 10 March 2015 at 11:27pm
Well, I have piggybacked every ls157/ls283/ls04/ls163/ls169 and no change arrrghh]]>
Subject: Taito Bubble Bobble Repair Log
Posted: 09 March 2015 at 11:36pm
which ttl's are the counter's?]]>
Subject: Taito Bubble Bobble Repair Log
Posted: 09 March 2015 at 11:30pm
thanks for responding! I've already piggybacked a new 157 over all the 157's and no change]]>
Subject: Taito Bubble Bobble Repair Log
Posted: 09 March 2015 at 9:26pm
Looks like a TTL error, but hard to say where or what is happening exactly.
It could be a counter, or simple inverter causing this screen offset issue.
Look at the http://wiki.arcadeotaku.com/images/f/f7/Bubble_Bobble_-_Schematics_-_English.pdf">schematics and try to find the video ram adressing. Something must be stuck somewhere. (lucky guess, a '157 somewhere?)
Subject: Taito Bubble Bobble Repair Log
Posted: 09 March 2015 at 12:52am
Anyone have a hunch here?! ]]>
Subject: Taito Bubble Bobble Repair Log
Posted: 08 March 2015 at 1:22am
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Subject: Taito Bubble Bobble Repair Log
Posted: 08 March 2015 at 12:56am
I'm stumped on another project. I recently got a Bubble Bobble bootleg board and when I wired it into my cab, the game boots up into attract but won't take any credits and the screen is divided in two - the background images on the left and all sprites on the right. I have no clue what might be causing this. i'll try and attach some photos - thanks again!
http://s172.photobucket.com/user/karatechamp999/media/IMG_5629_zps2qchhhjr.jpg.html
http://s172.photobucket.com/user/karatechamp999/media/IMG_5626_zpsl4maftbu.jpg.html
I've jumpered JPA and JPB still no coin up - I think the test screen is supposed to show colour gradient in the middle of the grid but it seems to be black in the middle (although there are good colours in normal mode) and the grid is half off the screen to the left just like the title screen
well found a busted pin - fixed. - and a diode soldered in backwards - fixed - still the same issue though :( anyone got a lead on this??? its seems to be a pretty specific issue
Progress!!! ok, game coin-ups now (twas a gap in the cabs coin ground, so I just service switched it, even though the cab doesn't have a service switch) So now I can play, all the controls and player starts work - Only issue left is the screen -
Bob and Bub are confined to the very left of the screen, I can jump up the levels and even though bob stays in the far left, I can phantom move and interact with other sprites, (who also are stationary in other parts of the screen, except for up and down) , like enemies into bubbles and pick up fruit even though there is no VISIBLE movement horizontally
Both background and forground seem to be split as seen in the photos, intro screen is the same background to the left and forground to the right
Also I'm noticing (visible in the bubbles in photos) with sprites fall down the screen, there is an invisible horizontal line the scrolls with it that seems to run through the other sprites and text giving a scroll through effect.
- looking like one of the IC's or RAM has a fault, just not sure which might cause this, already piggybacked ls157's and ls283 with no success
- pin 11 of IC 97 LS374 was broken, I soldered it back, and checked for trace cuts, and cleaned between all the pins on the video PCB
????
after test mode grid (also half off the screen) see attached photo - not sure if this means it passes ram test because that part is off the screen.
does anyone know what it looks like if it doesn't pass the ram test? would I see something on this side of the screen?
also I checked voltages on all the chips on the video pcb and all are good]]>
Subject: ESWAT/Golden Axe De-suicide/Conversion
Posted: 06 March 2015 at 10:11pm
Nice work to all involved :)
- Ben]]>
Subject: ESWAT/Golden Axe De-suicide/Conversion
Posted: 06 March 2015 at 7:59pm
I had been searching for a Golden Axe PCB for a while and after being pipped at the post every time one came up for sale, I saw on UKVAC that alpha1 had an ESWAT for sale. cmonkey had also posted in the thread to say that this PCB could be converted to Golden Axe so I asked cmonkey if it was an easy conversion (by which I meant no soldering) and he confirmed it was, so I grabbed it.
The ROM board is the 171-5797. The conversion was seemingly easy, grab the decrypted program ROMs from Porchy's website, burn the other ROMs from MAME, change the jumpers according to the MAME driver (which according to the MAME file are for ROM size) and your done.
I looked at the MAME driver (segas16b.c) and the details for Golden Axe (lines 635-669) showed a differing number of ROMs to the Golden Axe ROM file. On further inspection the ROM numbers for row B matched those of Shinobi and not Golden Axe (Row A matched Golden Axe). I spoke to cmonkey who confirmed that the MAME driver was incorrect. I wanted to burn the ROMs as per the MAME driver to see what would happen, but cmonkey talked me out of this (I might still do it).
I burnt the ROMs, using 27c020's for IC's 1-2 and 9-14 and 27c010's for IC's 19-21 and 6. I changed the jumpers and it seemingly worked. However The sound was wrong and the background graphics were missing from level 3 onwards. At first I thought it was the ROMs however I checked the ROMs and all were fine, I then replaced all the ROMs in case one was faulty but no change. I wondered if the board was faulty however it worked perfectly as ESWAT.
cmonkey suggested speaking to Porchy and Porchy said to try different program ROMs in case the encryption removal had failed on one of the dumps. I tried all the variants of the program ROMs and no change. Porchy then suggested that maybe all the dumps may not be working as testers may not have checked past level 2, however cmonkey built a version of MAME from source specifically for these dumps to test and confirmed that they were working fine all the way through.
Another ESWAT board came up for sale so I grabbed it in case it was a problem with the board. The new ESWAT arrived and the problem still existed!
I had my suspicions that the issue was down to the use of JEDEC ROMs for the video/audio so ordered some from China and I am currently waiting for them to turn up. I then saw an original Golden Axe up for sale on UKVAC, it had a very high res picture, so I could zoom in. The jumpers were the same - good, looked at the ROMs and IC's 19-21 and 6 had non-JEDEC Roms (m27c1000). Soon after a Golden Axe conversion came up for sale, again jumpers the same and IC's 19-21 and 6 were again non-JEDEC (27c301). Realising that when my non-JEDEC ROMs will turn up it will solve the issue, I messaged cmonkey and Porchy to break the good news.
cmonkey came back and said maybe the jumpers also decide the ROM type. I had thought of this before but the MAME file says S1-S16 configure ROM sizes and my multimeter is elsewhere so hadn't checked. Looking around I found a diode tester and thought I would try it. I tested the pins closest to the ROMs and got funny results. I assumed this was because i was using a diode tester. I then tested the pins furthest away from the ROMs and BINGO! Jumpers S1 and S2 were both connected to Pin 2 of the Video ROM, Jumper S5 and S6 were both connected to Pin 24. I then checked all the jumpers and these are the results:
Jumpers S1-S6 : IC's 19-21
S1: A16 to Pin 2 (short for JEDEC ROMs, open for non-JEDEC ROMs)
S2: OE to Pin 2 (open for JEDEC ROMs, short for non-JEDEC ROMs)
S3: ROM size 1mbit (short for Golden Axe, open for ESWAT)
S4: ROM size 2mbit (open for Golden Axe, short for ESWAT)
S5: A16 to Pin 24 (open for JEDEC ROMs, short for non-JEDEC ROMs)
S6: OE to Pin 24 (short for JEDEC ROMs, open for non-JEDEC ROMs)
Jumpers S7-S10 : IC's 9-14 and 22-23 (all 2mbit)
S7: OE to Pin 24 (short for JEDEC ROMs, open for non-JEDEC ROMs)
S8: A16 to Pin 24 (open for JEDEC ROMs, short for non-JEDEC ROMs)
S9: A16 to Pin 2 (short for JEDEC ROMs, open for non-JEDEC ROMs)
S10: OE to Pin 2 (open for JEDEC ROMs, short for non-JEDEC ROMs)
Jumpers S11-S16 : IC's 6-7
S11: A16 to Pin 2 (short for JEDEC ROMs, open for non-JEDEC ROMs)
S12: OE to Pin 2 (open for JEDEC ROMs, short for non-JEDEC ROMs)
S13: ROM size 1mbit (short for Golden Axe, open for ESWAT)
S14: ROM size 2mbit (open for Golden Axe, short for ESWAT)
S15: A16 to Pin 24 (open for JEDEC ROMs, short for non-JEDEC ROMs)
S16: OE to Pin 24 (short for JEDEC ROMs, open for non-JEDEC ROMs)
IC's 1-2 Don't appear to have any jumpers connected so are always JEDEC ROMs.
Hopefully this will help someone in repairing/de-suiciding/converting an ESWAT/Golden Axe.
It also means that in theory, it is possible to have a dual ESWAT/Golden Axe by bank selecting the ROMs with remote jumpers for S3/S4 and S13/S14, but that is a project for someone else.
Many thanks to both cmonkey and porchy for helping me getting this resolved.
Edited by simonden - 06 March 2015 at 8:08pm]]>