CPS2 no sound, only boots rarely

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    • CPS2 no sound, only boots rarely

      First off, sorry if this is not the form to post under. I didn't see a general support forum for CPS2 outside of the multigame one. If there is a better location, can you please move it?

      I picked up a Japanese CPS2 A+B set (Vampire Hunter: Darkstalkers' Revenge). Took the battery out.

      I burned the CPS2 test rom, and it showed all chips as GOOD. But I had no sound coming out.

      Inserted phoenixed roms, dead screen.

      Inserted test rom back in, and now I get an error: Sound Init BAD

      I removed roms 1 and 2 and the Qsound roms, cleaned the legs, re-inserted fully. Still told the Sound Init is bad. =/

      Replaced the test with phoenix rom 3. It booted up! But no sound. I turned it off.

      A few minutes later I turned it back on and nothing on the screen. Turned it off and on, and it loads, but still no sound.

      I checked and don't see any bulging or leaky capacitors on A or B boards.

      Board is getting +5v and +12v using an arcade power supply.

      tl;dr always starts with cps2 test rom, but with phoenix roms only starts randomly (best luck when I turn off then immediately back on). Never any sound (though some slight humming)

      Any suggestions on what I could try on this? Places solder might need to be reflowed or anything?
    • Not sure if this will help you, but when I fired up my CPS2 again after it being unused for several years, I initially also had no sound out over the JAMMA edge connector. I then used a pair of powered speakers connected to the RCA jacks and everything came back to life also the mono sound over the JAMMA edge connector ...
    • I did try holding down volume down while powering up. The volume was set to 0, as confirmed by the test menu. I then cranked it up to the max, but still no sound.

      I dumped roms 1 and 2, and got different CRC-32s than what I found listed online. Both chips are CXK27c1000dq-15.

      Could it be these two chips went bad and would give the different values? And if so, could this be the cause of no sound and the bade Sound Init? The Capcom stickers on them don't seem to be altered.

      My values:
      rom1: 7B5D6010
      rom2: CBAA962E

      I dumped a few other chips and they all had correct CRCs.

      Should I try to reflash them with what I found online?

      The post was edited 2 times, last by Stupid Dufus ().

    • Well, I tried some other B boards (SF Zero, SSF2X) and still no sound, so I'm guessing it's the A board that has the sound problem. As for Darkstalkers not booting every time, I think it's the game board itself.

      So I've tried sound from the jamma connection as well as the RCA jacks. Just humming/buzzing sounds that vary slightly depending on what's being displayed (intensity of colors).

      Is there anything on the A board you would suggest? Specific spots to check for bad solder connections? Cap replacements?
    • Do you have a logic probe with audio? Start with a logic probe at the furthest cap from the amp (in the audio circuit). If you are getting audio via the probe, then cap(s) are your problem. If you don't get audio there, then your problem is further upstream.

      Have you also changed the settings in the test menu, between "mono" and "Q sound"? I believe some boards will not output to JAMMA connector and RCA outputs at the same time, whereas others will.

      I recently had a SFZ3 that was boot looping. Although I had reseated the roms multiple times, it turned out to simply be one rom that appeared to be inserted fully, but after applying a significant amount of force pressing it in, it finally snapped into the socket, and haven't had a problem since.

      I find using romident is the most reliable, for verifying the contents of roms. Just dump the rom, and upload to romident. It will tell you what it belongs to. If it doesn't identify a game or games that it belongs to, then it's likely corrupted or faulty. The MAME sets should be static, but I've found some of my sets, dating back to who-knows-when, won't verify even though the rom is fine.
    • Unfortunately I don't have a logic probe.

      I did try changing settings between Q Sound (stereo) and mono. Didn't have luck either way.

      I feel the issue is probably with the A board though, because I've tried three different B boards now, all have no sound, but...

      Thanks for the link to romident! I threw in the two sound program chips I dumped from Darkstalkers Revenge and got unknowns. Loading them up in a hex editor and comparing them to two ROMs I found online, it seems mine have FF halfway through each one. I'll be testing with the other two game boards (SSSF2X, SFZ1) from now on.

      In the meantime, I've ordered the supercap and the huge axial cap. They should arrive in a few days. Once they arrive, I'll post with the results.
    • Stupid Dufus wrote:

      I threw in the two sound program chips I dumped from Darkstalkers Revenge and got unknowns. Loading them up in a hex editor and comparing them to two ROMs I found online, it seems mine have FF halfway through each one.

      Sounds like it's not reading the rom fully. Could be down to wrong eprom selection in the program or one of the legs not making good contact with the programmer.
    • Stupid Dufus wrote:


      In the meantime, I've ordered the supercap and the huge axial cap. They should arrive in a few days. Once they arrive, I'll post with the results.
      Well, I replaced these two caps, and there's been no change. =(


      nem wrote:


      Sounds like it's not reading the rom fully. Could be down to wrong eprom selection in the program or one of the legs not making good contact with the programmer.

      Excluding Darkstalkers Revenge, which might possible have bad Sound Program chips, I've tried with two other boards.

      Other than doing a full recap on the A board (don't know if it'd fix the issue anyway), any other suggestions on how I might fix the audio?

      As mentioned above, I don't have a logic probe.

      I should have another A board within the week to test if it really is the problem. I'd still like to get this current issue fixed though if possible.
    • Got a new A board in and sound works perfectly with all three B boards. And all start up with zero issue, whereas with the problematic A, sometimes they won't start unless I power cycle up to 10 times. Hmm..

      I'd like to get the bad A fixed up at some point. Will see if I can swap out the z80 or something to fix the sound problem at least.

      Thank you everyone for the suggestions so far!
    • Opening up the new A board, it looks absolutely pristine and clean inside. But everything is soldered in to the board it seems, whereas the bad A board has the z80 and others in easily removable mounts (the word escapes me for those at the moment).

      Because of this I'm not going to bother removing parts from the good board to test with.

      Now that I have a good A, what would you recommend I do with the bad one? Try to fix it later on, or sell it as broken?