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Teenage Mutant Ninja Turtles Arcade PCB repair

nam9

nam9

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Hi!

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...

DSC02335.JPG

Thanks in advance!
 
They are not readable from the photo, but almost certainly they are 100nF 50V. Do not expect a cigar on this, however; the audio section if I'm not wrong is around the center of the board.
 
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...
 
If you have the means, pull the ROM chips, dump them, and compare the dumped CRC values with MAME. You may have a flawed ROM chip.
 
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!

Thanks!
 
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
 
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...
 
yavuzg said:
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...
Click to expand...
:D

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 said:
Can those two tantalum caps be replaced with electrolytics?
Click to expand...
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...
 
I have a TMNT PCB here that I just repaired for a friend. Symptons were distorted audio when certain sound effects were triggered.

Not bothering with a repair log as it was just 2 x capacitors that needed replacing.

Echoing the info here, replacing C6 and C74 with new 4.7uF 16V tantalum capacitors fixed it right up.
 
Ive found some articles about op-amps, others about replacing the caps.
There never seems to be a solid answer.
 
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Hmmm ... a few thoughts:

1) Definitely replace the caps first if it hasn't been done already.

2) A bad solder joint on one of the SMD chips could be your culprit as well. Metal expands as it heats so a pin might make a connection when it's cold but then lift up just enough to break the connection when the chip heats up.

3) Buy some cold spray and spray small sections of the board after it's heated up and the audio distorts. If the audio clears up where you've sprayed, you found your target area.
 
Totally agree with the above. Replace the caps first, then check for a cold solder joint.

How hot does the amp get?

I prepared a capacitor list from the schematic for the voice and sound sections. I'll share it with you, may save you some time. It's scribbled down on a piece of paper, I'll type it up here soon.
 
Here's the capacitor list for TMNT. I believe this is all of them, let me know if I missed any.
  • C2 - 220uF 16V electrolytic
  • C3 - 0.1uF 100V polyester
  • C4 - 10uF 16V electrolytic
  • C5 - 100uF 16V electrolytic
  • C6 - 4.7uF 16V tantalum
  • C7 - 4.7uF 16V tantalum
  • C8 - 4.7uF 16V tantalum
  • C9 - 470pF 50V ceramic
  • C10 - 10uF 16V electrolytic
  • C11 - 470pF 50V ceramic
  • C12 - 4.7uF 16V tantalum
  • C13 - 4.7uF 16V tantalum
  • C14 - 30pF 50V ceramic
  • C15 - 4.7uF 16V tantalum
  • C16 - 0.1uF 100V polyester
  • C17 - 0.1uF 100V polyester
  • C18 - 4.7uF 16V tantalum
  • C19 - 100uF 16V electrolytic
  • C20 - 1000uF 16V electrolytic
  • C21 - 0.1uF 100V polyester
  • C22 - 0.022uF 100V polyester
  • C23 - 4.7uF 16V tantalum
  • C66 - 4.7uF 16V tantalum
  • C67 - 1uF 16V electrolytic
  • C68 - 0.033uF polyester
  • C69 - 220pF 50V ceramic
  • C70 - 4.7uF 16V tantalum
  • C71 - 0.01uF 100V polyester
  • C72 - 100pF 50V ceramic
  • C73 - 4.7uF 16V tantalum
  • C74 - 4.7uF 16V tantalum
  • C75 - 220pF 50V ceramic
  • C76 - 4.7uF 16V tantalum
  • C77 - 0.022uF 100V polyester
  • C78 - 0.022uF 100V polyester
  • C79 - 100pF 50V ceramic
  • C81 - 0.033uF 100V polyester
  • C82 - 0.022uF 100V polyester
  • C83 - 0.033uF 100V polyester
  • C84 - 4.7uF 16V tantalum
  • X1 - 640 KHZA (resonator - Murata - part # CSB640J)
  • X2 - 640 KHZA (resonator - Murata - part # CSB640J)
These are all the caps and two resonators listed within the SOUND and VOICE sections of the schematic.

In a table for easier sorting:
REFQTYTYPEVALUEVOLTAGE
C671Electrolytic1uF16V
C4, C102Electrolytic10uF16V
C5, C192Electrolytic100uF16V
C21Electrolytic220uF16V
C201Electrolytic1000uF16V
C6, C7, C8, C12
C13, C15, C18, C23
C66, C70, C73, C74
C76, C84		14Tantalum4.7uF16V
C141Ceramic30pF50V
C72, C792Ceramic100pF50V
C69, C752Ceramic220pF50V
C9, C112Ceramic470pF50V
C711Polyester0.01uF100V
C22, C77, C78, C824Polyester0.022uF100V
C68, C81, C833Polyester0.033uF100V
C3, C16, C17, C214Polyester0.1uF100V
X1, X22Resonator640 KHZA
 
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Resonators are listed, X1 and X2, with values and part numbers.

I went ahead and recapped the entire TMNT board I have here. Verified that all the caps listed are correct. The only remaining caps that aren't listed are about 8 or so 0.1uF ceramics used as power filters on ICs.
 
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