Teenage Mutant Ninja Turtles Arcade PCB repair

    • Teenage Mutant Ninja Turtles Arcade PCB repair


      I have TMNT pcb with dodgy sound... The music cuts in and out on some levels - on others its fine.
      I haven't done much by way of trouble shooting yet, just starting with this obvious issues.
      Can anyone help identify the ceramic caps in this picture? They are both cracked and need to go.
      I can't really make out details on them...

      Thanks in advance!
    • Thanks again for your help. I'll get some ordered up.
      I've since pulled up a schematic and yes, these are unlikely related to audio.
      Just starting with the obvious faults before i start troubleshooting more complicated issues.
      Actually there seem to be a few threads regarding sound issues on these boards... none with simple fixes it seems...
    • WIP.

      This thread over on KLOV resolved similar sound issues on a TMNT board by replacing Tantalum caps in the sound section.
      The caps in question are marked 4.7U16T on the board and in the schematics.
      Am I correct in thinking this translates to 4.7uF 16v Tantalum caps? (Its really the voltage I am unsure about).

      And yes... I am blind testing the most straight forward fixes I can research online in lieu of the more competent suggestion made above.
      This is just a function of my current skill level related to arcade repairs... I still appreciate the input!

    • I was researching TMNT sound issues recently as well, apparently there is a common failure that prevents certain sound effects from triggering at certain times that is related to a failure of one of the 74 series ICs. other common failures around the op amp ICs (scratchy sound fx) and others around the ceramic oscillator (sound cutting in and out).

      They all seem easier to fix than the X-Men sound issues but more difficult to track down.

      I find it ironic that Konami had so many PCBs with sound issues, and then went on to concentrate almost exclusively on music games. :D
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    • yavuzg wrote:

      I've written that repair log :)

      Read the thread till the end though since there were some false alarms there...

      The ultimate solution for my board's sound problem was to replace the 4.7uF tantalum capacitors (C6 and C74).

      good luck...

      I can only cross my fingers that I have the exact same issue as you had there... (graphics aside).
      Still needing to order the replacement caps... can you confirm 4.7uF 16v Tantalum caps?

      SmokeMonster wrote:

      Can those two tantalum caps be replaced with electrolytics?
      The silk screening indicates polarity (iirc) and I believe @yavuzg used electrolytics initially, but switched to tantalums for the sake of originality [sic].
    • I do not have that PCB anymore (sold it to raise some funds for my never ending pinball restoration - damn! pinball parts ARE expensive) but still can confirm what I've written. Yes, the electrolitics worked and later changed them with tantalums. Both types of capacitors have polarity but have different characteristics. Didn't wanted to change what the designers intended to...