My adventures with this board i got off ebay for super cheap. Listing said not booting, and had some pictures of previous repairs when i got it, i hooked it up to an ATX psu and my neogeo/Jamma test harness and she did boot up, but my CRT TVs didn’t like the RGBS and wouldn't stay in sync i assume due to voltage but no matter. I hooked it up to my GBS 8220 and a VGA monitor and bingo all good, Although at this point i had not wired up any sound. I noticed it was running faster than it should be, but this apparently is normally for bootlegs of the time (board is dated 1992) so not over worried about it as it still plays well and sound is in sync. Now here in lies the issue with the board, Sound, there is no FM sound, i have the digital sound effects and voice etc from the OKI chip so that is working fine, but no music / fm sound. So i took a closer look at the repairs previously done, 2 capacitors in the sound circuit had been replaced, a trace from the cpu clock crystal to the 68K had been repaired, and there's a wire jumped from the Ground on the jamma connector going to the "Audio -" pin (also on jamma connector) Anyway after a closer look at the caps(repair looked well dodgy) they were the wrong value, 47uf instead of 470uf, so i went out grabbed some 470uf caps and stuck them in, powered up the board, and although the sound was much improved, there was still no FM sounds. As this is a CPS1 clone board it uses a lot of the same chips (Z80, 68000, OKI sound chip) but does have some generic clone chips, labelled AU301 and AU302 with no other markings 24pin and 16pin respectively. After some research i couldn’t find anything on these so decided to look at what the CPS1 had in it's place, which seems to be the Yamaha YM2151 and YM3012. that aside as these chips are a bit more expensive and take longer to arrive, i decided to also look at the op amps, of which there are 4, one of which looked a bit odd like it'd either went bang at one stage or oozed something i initially thought this was some flux someone had dripped onto the board and not cleaned up so ignored it. So I’ve now removed this and ordered some op amps (RC4558 DIP8) and will probably replace all 4 but just the one for starters when they arrive. currently have no logic probe so can't really test the clone chips much so if the op amps do not work i may just replace these anyway with the yamaha chips. for what the board cost me, i don't mind spending a few £ on it to get it working right. as it's a cool thing to have. As for the version of SF2CE on the ROM chips i have no idea which version it is, as there are many, it looks mostly stock other than the increased speed. I'm unable to dump the chips as i don't have a reader/programmer so my only point of reference is trying different versions in mame. that being said, if i need to replace the sound rom knowing this information would be helpful. The one chip that is labelled is "R150 DASH-7" I know SF2CE was known as DASH in Japan. So Progress has been made, but baby steps. I am curious as to why whoever worked on the board before me added a jump wire between ground and audio - on the jamma connector, there doesn't seem to be any issues with the traces, although I’ve not tried to remove it yet. Has anyone seen one of these boards before? I don't mind screwing around with it as it was cheap and just got it to play with but it would be nice to get it working fully as it's so close to it.
Update #1 Issue noticed: that when i adjusted 10k volume pot to raise volume board seemed to loose sync picture became jumpy and unstable. New op amp ICs arrived Replaced 3 of the 4 op amps (1458TC) with new RC4558's (which is what the board is silk-screened for anyway) Removed the wire that someone added in the previous repair jumping from jamma ground to Audio - Pin Improvement: sound has improved also, and previous issue with screen jumping when volume raised via 10k pot is now gone. New issues noted: Seemingly more dead components in the audio circuit, 2 ceramic capacitors near the originally dodgy looking op amp, and 1 directly after the trace repair/jump wire from 470uf cap that i previously replaced. To do next: replace blown ceramic caps(need to order) Slow progress, but progress none the less. Tempted to just rebuild the whole audio circuit but really could not be annoyed at replacing every single resistor yet, all the ones I’ve tested so far have been fine. Also it could still be that the AU301 and AU302 chips are bad or at least 1 of them is. but replacing these is more of a last resort.
pictures en-route meant to add some to original post but have been too lazy lol. pics from before i started working on itnot taken by me) zoomed out pic of board trace repair 10mhz crystal to M68k Jump wire from JAMMA ground to Speaker - and from replaced capacitor. Video i took: [video=youtube_share;a0BVCmUDZzQ]http://youtu.be/a0BVCmUDZzQ[/video]
Update #2 Video: The Journey of under-equipped noobyness continues. [video=youtube_share;gY0cbRUvsWE]http://youtu.be/gY0cbRUvsWE[/video]
Well it's definitely the YM2151/3012 audio, probably some damage to the mixing circuit, not likely the op amps or the speaker amplifier (along with the big electrolytics). You know the amplifier works because the PCM comes through. IF it's an op amp, it'll be the sample-and-hold buffers after the 3012/DAC. I have the same board too but haven't had a chance to try it out. Wasn't sure how well it played since the hardware isn't so much of a CPS clone as it is a stripped down cost-reduced version (along with hacked program ROMs to suit). From your video it looks pretty good but I can't tell if the ground parallax effect is missing.
well as said the op amps or at least 1 of them looked a bit suspect so was replaced and that did improve matters, the big electrolytic were replaced as whoever worked on the board prior to me put the wrong value replacements in. if replacing the other dead parts does not work then I’ll go straight for the YM2151 and 3012. leaving them til last as they're a bit more pricey than the rest and would need to import them from HK/China or the USA. It plays pretty well and looks really nice. other than the increased speed, I’ll give it a real play through once i have the kick harness etc wired up(and the audio working) i'll have to fire up the original on mame to compare. and i really should get a logic probe for screwing around with these arcade boards lol. Edit for update: Parts now on order: Ceramic caps: 101/102/104 (should arrive this week) YM3012 from HK/china YM2151 from HK/china And some solder as i was running low, also tempted by another arcade PCB i see. May still replace the 74LS273 that had a bit of corrosion on it but first things first. sound!
(Not so) Small Update: Caps arrived, YM3012 arrived Still waiting on the YM2151 What's happened: Replaced final op amp - just because i wanted to no other reason and i had a few spare Replaced damaged caps. Took some more readings with multi meter from the big caps i replaced and also from the "AU302" chip - of the 2 470uf capacitors i replaced, one is holding voltage at around 6.5v the other is fluctuating everything that needs 5v is getting it and same with 12v - curious point to note, the board is silk screened and has "holes" for a 7805 and a "CN1" the latter i think was to be a 3 pin connector, the 7805 a voltage regulator which does not seem to be needed as readings from where it's pins should have been read 12v in and 5v out anyway... so i assume CN1 was to be an AUX 12v power input? meh it looks as if it's been this way from factory rather than the parts having been removed by someone for whatever reason. tested board: still same as expected, so next i disconnected the jump wire from the replaced 470uf cap with the stable voltage, powered up board: no change, I then removed the AU302 chip (board is labelled for YM3012 as expected) i decided to power on the board with the chip removed and boom! No it didn't blow up, it was exactly the same digital sound and no music / fm sound. what's next: Add socket for the YM3012, add YM3012 to socket, test board with new chip. as the YM2151 isn't here yet i can't do anything much before the DAC, so that just leaves possibilities after if the 3012 doesn't fix the problem, possibly some of the other electrolytic caps may be bad, there's a funky resistor somewhere that i've missed, the Hitachi HA13001 amp may be to blame, or going backwards a bit down the chain: sound ram issue, sound/music rom issue. but i doubt the latter. So i'm taking a break as i'm tired and have other things to do but will get back to it later on and fit the socket and new DAC **Edit Big Update** No longer any need to wait on the YM2151, it's 2:49am and i woke up, so decided to throw the socket and new YM3012 into the board aaaand Bingo! FM sound has returned! Previously i was getting 0.19ish volts on pin 12(Analogue output > buffer) of the YM3012 and a fluctuating voltage on the channel output pin (9 or 10 CH1 and CH2 output, one is not used). Now: getting nice fluctuating voltages averga about 2-3v from both pin 12, 9 and 10 on the YM3012 with music constantly playing(from IO Test > Sound in test mode(DIP switch #8) and capacitor is doing its job voltage has dropped slightly on the cap to around 6v. So basically FM sound goes from the DAC > Op amps > HA13001 > 470uf Electrolytic caps etc > output pin, of the two bigger 470uf caps near the HA13001 the lower on is for the Digital voice and SFX, the upper one is for the FM sound / Music or at lest so it seems. Yes i am a noob and some of this may have been obvious to people more in the know, but it's a learning exercise and a bit of fun tinkering with a cheap board. What next: Testing! of course, and a video, but also the HA13001 should really have a heatsink so i'll probably stick on on it, the YM2151 has not arrived yet, but i may still remove the generic AU301 chip and replace it with the new one. Also, when i put in my next order for capacitors i'll replace the rest of the EL radials on the board as they're pretty old now all the way from 1992. Going to look at the ICs that had a little corrosion on the legs as previously mentioned and wire up a kick harness for it and add a DB15 or other connector for these 6 button games. but the main problem is fixed.
le video of board now working with full sound. just small graphic issue [video=youtube_share;U2xivS3lR48]http://youtu.be/U2xivS3lR48[/video]
Sorry to necro this old thread, but I wanted to thank synrgy87 for the great write-ups and videos of this interesting board. I picked one up recently and the information was invaluable. I have started recapping mine, and will finish it off when my next digikey order comes in. The audio is fine on mine, but I may end up socketing and replacing the audio chips just for the hell of it. I'll remove the extra wiring then too. It looks like I have a different revision though. Mine has different clone chips and a 7805. The 7805 is pretty much pointless with a good power supply, because it just takes 5V in and sends 5V out. Parallax effects are there and the speed is correct on mine.
Could anyone who owns the board please help me identify a resistor's value? The resistor is too burned for me to make out its colors. Below is a picture. Also, is there is anywhere to tap line-level audio from on the board?
That is a slightly different revision, I'll dig the board out and check the capacitor for you. and post back Ok having looked at the resistor in the same location on my PCB it looks a different value to yours with just a single black band which is 0 ohm resistor, can't make out what yours is from the pictures. but seems to be a higher value? Maybe it was previously replaced with whatever someone had lying around OR much more likely as your board has a 7805 in, that resistor seems to link the 7805 with the same line the capacitor C33 which is linked to pin 1 of the jamma connector. Mine is probably 0 ohm link as there's no 7805. For some reason i couldn't reply to your comment on youtube
Thanks for the response and explanation. I used a magnifying glass and bright light, and I think that the resistor is either 46 or 47 ohm (yellow, purple/blue, black, gold). I'm 100% sure about gold and yellow, and either purple or blue. I'm not sure if the black line is just burned though. Would 46-47 ohm make sense in that spot? Today I finished replacing all but the three 470uF caps (some nice 470uF replacements are on order) and fired it up again. All of the sudden the colors pop and the image quality is crystal clear. The midrange and bass are back in the audio now too. This is actually a really nice boot when it's up and running. I'm still searching for a place to tap line-level audio, if it's possible.
I had the idea to remove the resistor to see if the board was marked, and sure enough "47ohm" is printed just beneath it. I swapped it out and finished the recap. Audio and video is now perfect. I wish my CPS-1 SFII-WW was so eash to work on. As soon as my eprom sockets arrive, I'll go ahead and swap out the audio chips too.
