Newbie, 1st machine bought at auction-it's a mute!

[headachenko]

hello all,
I recently bought a Heiwa Batman pachinko at auction...the problem I discovered is there is no sound. My brother-in-law has the same machine (only his is red/yellow, mine is black/silver) and when we plugged his sound board in...We got Sound! I've taken the defective sound board to a couple places and received no help/info. as to how I can remedy the problem. Any ideas as to who might work on Heiwa sound boards, or if a new board could be purchased?
Thanks in advance

[Moparformances]

Welcome to Pachitalk

parts can be really hard to come by possable some one had a broken machine/cell you can get parts off of.. or have the board remanufactured.. but that can get a little spendy..

sorry to hear about your machine..

[TilionMtl]

ok, it will sound really stupid to say that, but while there's supposed to be some sound (like when numbers are spinning for example) have you tried to play with the little switch on the side, trying to move it to see if there's a bad contact? I would do the same with the connectors too, maybe one of them don't make connection properly on your board. Try it while sound is playing, so you can hear a mute/sound-clipping/mute.

[headachenko]

Thanks Tilion, we did play with all switches/connections attached to the sound board while machine was operating. My brother-in-law also replaced the capacitor, still nothing.

[Moparformances]

My brother-in-law has the same machine (only his is red/yellow, mine is black/silver) and when we plugged his sound board in...We got Sound!

by any chanch did ya try your board in his machine???

[headachenko]

Yep. We did try it in his machine...to no avail.

[Habious]

I would think this would be a cinch for any decent electronics technician.

It's one thing to try to troubleshoot a board with no schematics or anything but, you've got the holy grail of troubleshooting...and known-good unit!

Put the 2 units side-by-side on a test bench and run through every component with an Octopus...and see where the units differ; that'll be your problem area.

Granted, if it's one of the 3 chips on the board, you're pretty-much screwed unless they happen to be off-the-shelf IC's (can't see ID numbers from your pic). However, if it's anything else (I see a dozen transistors that look like tasty possibilities), then it's an easy fix.

[mudfud]

hey habious,

thanks for the link to the octopus tester circuit. I hadn't heard of that, but now I will build one.

[pinball wizard]

[Youngjedi]

Are there any capacitors (little beer can shapes) on the board? If so, do any of them have a rounded head? If you find any with a rounded head, the cap is blown. Easy to replace. You may find the exact number at Mouser. Mouser Electronics - Electronic Component Distributor

[rubberratt]

It sounds like you have proven the sound board is bad
Unfortunately... these circuits are not designed for "discreet" repair work.
I would ask Kiai if he could source one for you.

[takethecastle57]

http://www.smcelectronics.com/CIRCUITS/OCTOPUS.PDF
______________________________________________________
Octopus Ocilloscope Adapter
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Electronics Hobby

[takethecastle57]

Circuit Libraries, E-zines, & Links

[drcrippen324]

im with mudfud on that one in all my time never come across an octipus tester but i can see one getting added to my arsnal very quickly for pin repair

[Drunkenclam]

I haven't got an oscilloscope

[headachenko]

Wow, I had almost given up on this post...Thanks Habious for rekindling it. The #s on the (3)chips are tough to read with certainty, but I believe the one on the right is:
NEC Japan
078P083CU
0228EY010

Middle chip is:
YAMAHA JAPAN
YMZ7708-F
0223 AAVD

Left chip is:
M27C322
-100S1
5280Z
0215L
MALTA

Do any of these appear to be "off the shelfers"?? Or am I indeed screwed if the problem lies there??

[headachenko]

It sounds like you have proven the sound board is bad
Unfortunately... these circuits are not designed for "discreet" repair work.
I would ask Kiai if he could source one for you.

Thanks rubberratt, but I must ask, who is this Kiai you speak of?

[Habious]

OK, well looks like good news and bad news...

The first chip, I THINK, is an NEC 78K0R Microcontroller.

Second chip seems to be a Yamaha YMZ7708-F chip...which I'm betting is a musical instrument tone generator...this page is in Japanese and Google Translator is having problem with it. Anyone here who can translate the page?

Third chip is an STMicroelectronics M27C322-100F1 EEPROM.

If it's the EEPROM, you're pretty-much SOL. Not only are they discontinued, but they're programmable so, if it's toast, you'd need to get a new one...AND find a way to copy the program from the good one to the bad one. It's POSSIBLE to do, but not easy (unless you happen to have an EEPROM reader/writer compatible with that chip lying around the basement - I don't...I looked!)

I won't worry much about the chips. They RARELY smoke on their own. If something fried bad enough to cook one of the chips, you're going to have MANY other problems, and it'll be obvious.

[MrFixit]

Have you looked for someone with a similar unit willing to part out?

[headachenko]

I have inquired on a few Batman Craigslistings as to parting out of just the soundboard...no luck thus far.