Repair Log: Snow Bros PCB Audio (PX4460 removal/alternative)

[xodaraP]

Have you tried replacing the other parts that replace the PX4460? Or did you just replace the electrolytics?

 

[evilsim]

Have you tried replacing the other parts that replace the PX4460? Or did you just replace the electrolytics?

Just the caps for now.
My board does not sport the PX4460 IC, just a MB3712 IC. I may buy a replacement MB3712 from ebay, they are not available at digikey.

Keen to get this working, SnowBros is right up there on my favourites list I have decent speakers and a sub setup next to my Astro cab so im not going to even play this until the sound works hehe

 

[stj]

does it have any op-amps??

 

[evilsim]

Please find pictures here @stj yes the OP amps should be visible there (4558 ?)

https://imgur.com/gallery/kV3b9zB

Imgur seems to never work for me when I paste a URL so heres some direct link to valid pics

https://i.imgur.com/7xTiUre.jpg
https://i.imgur.com/uavwdR8.jpg
https://i.imgur.com/tnecGdj.jpg

THANKS for any advice or help anyone gives me !

 

[evilsim]

GREAT.
got the replacement MB3712 IC. Desoldered the old, soldered the new. Fired it up.

Smoked on the new IC on pin 4..

Back to less than square one on this one...

edit: NExt I am buying a 4558 IC. Feels like this one is getting hot, without the MB3712 in place.. I can tap sound from the input leg of the 4558 IC, but its not clear audio

 

[stj]

when you replace an amp - make sure you read the old part number clearly.
there are mirror-pinout versions of many amps - including the mb3712 (mb3713 i think)

 

[ArcadeKG]

Now we're getting somewhere.

Snow bros seems to follow this schematic exactly:

PARTS LIST:

1x 1.5k resistor R25
2x 4.7ohm resistors R20/R24
2x 47uf axial caps C13/C15
2x .033u poly film caps C16/C17
1x .01u poly film cap C14

With these you should be able to remove the PX4460 entirely and never need one again for this game.

Hey bro any chance you can roughly draw up / SketchUp how you plugged in the passive components into the px4460 and surrounding through holes? It's not completely visible in the picture.