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Let’s talk about the flood of Chinese CPS-1 conversions on ebay

duffcon

duffcon

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So lately I’ve noticed a LOT of CPS1 conversions on eBay from China. These are obviously hack jobs, but some are rather interesting, sporting “reproduction” b-boards.

The one I have pictured has a really janky re-cap of the audio section. How is it so many cps1 boards are in China?

Any idea where these come from? Quality? Caveat emptor?
 

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Those caps make me cringe.

My guess is that there was a warehouse somewhere in China with a ton of CPS1 parts because quite a few CPS1 A boards and C board custom chips have been trickling out of there for the last few years. Arcade Hacker had a blog article about the available supply of 86,000 units of the B21 custom chip back in 2018:
http://arcadehacker.blogspot.com/2018/12/capcom-cps1-b21-chips-in-wild.html
 
that looks like it was originally an A-board from a Q-sound stack that someone re-populated the audio section of.

I recently got some CPS1 parts that included a bootleg B-board if anyone wants it.
 
I too noticed and was wondering about all those A boards. Have a small pile of A boards needing a working custom. . . .
 
I took a gamble on a forgotten worlds b-21 conversion. I guess worst case it’s a functional A&C boards for the darksoft multi. I’ll report back with results
 
Most of them have weirdly rebuilt A board audio sections. This has been going on for a long while, and seem prone to failure (see my ongoing struggles trying to repair one). I really don't get why they're doing what they're doing to the audio sections. I can't make heads nor tails of the strange diode arrangement on the Yamaha clone.
 
the weird thing to me is that these CPS1 setups would be much more valuable if left as the original Q-Sound games they were converted from. unless they had a glut of dying D-Boards; it doesn't make sense.
 
I purchased a ghouls n ghosts conversion with that sound setup on the A board.

It has legit B and C boards.

It works well *knock on wood*, but I was surprised to see the sound setup.

When I first powered up the unit, the sound wasn't working. I immediately blamed the strange sound setup, but reseating the B board solved the problem.
 
It looks like they are populating the missing audio section with the bare minimum number of caps and other components to have sound. So yeah, probably sounds like crap and not reliable at all.
 
andynumbers said:
It looks like they are populating the missing audio section with the bare minimum number of caps and other components to have sound. So yeah, probably sounds like crap and not reliable at all.
Click to expand...
The sound quality is the same (to my ear) as the original hardware.

I have 3 stock dash A boards to compare it to.

It certainly isn't crap.
 
Looks like they fit a mono amp. Not really a problem if playing in a pure JAMMA cab but you're missing someting in a stereo cab.
 
Some appear to be less crappy; this is “legendHK” - they use the same pic but have many different titles listed

B8D8E106-0E24-4764-AD8C-D8834A3064D7.jpeg
 
duffcon said:
That's encouraging; at least they have some kind of warranty.
Click to expand...
Took over a year for mine to lose audio, and I'm at a loss as to how to repair it because it's such a departure from what it should be... so far tried swapping the crystal, the z80 and the YM2151 (there was a clone chip in it's place KA51) and nothing. Going to try putting a YM3012 in where they have a KA12 and see what happens. Then I'm about out of ideas.
IMG_0878.jpg
 
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Step1 IMO is
-make sure everything that should be populated is populated
-make sure everything that shouldn't be populated isn't populated
-check for cut traces and wire jumpers
-replace clone chips with originals
-verify the model number/value of every component

realistically this is all 1 step because you don't know if that wire bodge or incorrect value cap was done to support the incorrect model or clone chip.

if it still doesn't work then Step2 is tackling it like any other non-working audio circuit... break out the audio probe.

of course Step 0 is avoid buying this junk in the first place.
 
twistedsymphony said:
Step1 IMO is
-make sure everything that should be populated is populated
-make sure everything that shouldn't be populated isn't populated
-check for cut traces and wire jumpers
-replace clone chips with originals
-verify the model number/value of every component

realistically this is all 1 step because you don't know if that wire bodge or incorrect value cap was done to support the incorrect model or clone chip.

if it still doesn't work then Step2 is tackling it like any other non-working audio circuit... break out the audio probe.

of course Step 0 is avoid buying this junk in the first place.
Click to expand...

Yeah, my concern is that something that is populated and should be populated is bjorked because of something that shouldn't be but is.

By audio probe I assume you mean something to check for audio before the amp? In my case, fairly sure the amp is OK. I do get audio sometimes, depending on which game I load, but it is a single sound used for all sound effects. Which says to me a memory or processor error. I guess I should break out the oscilloscope and logic probe, but I had the spare chips so started with that.
 
yes and no. An audio probe is a device that's basically a metal pin attached to an audio amp and a small speaker. so you can touch a pin on the circuit and "hear" the data on that pin.

think of it like an oscilloscope with audible output instead of visual

using that you can check the output pins of every chip in the audio circuit to determine where the failure point is.

you might be right that one of the clone parts damaged something else, but heck that can happen with some original parts fail too, it's best not to jump to conclusions until you've gone through all the basics first.
 
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