**Reel Slots** Gaming Machines => IGT S and S-plus Reel Games => Topic started by: PhillyArcade on September 12, 2022, 01:57:43 PM
Title: Sound issue on my S plus. Have a listen... *UPDATE Fixed!* Stop on in...
Post by: PhillyArcade on September 12, 2022, 01:57:43 PM
This sound issue just started. Before I start digging around replacing caps and such, I figured I'd ask here if anyone ran into this issue before and the cure. Sure don't look like there is much to the sound circuit! Thanks!
Here is a link to the video...
Title: Re: Sound issue on my S plus. Have a listen...
Post by: Tilt on September 12, 2022, 04:11:24 PM
I would try swapping the sound generator IC (U55) with a known working one and see if that resolves it.
Title: Re: Sound issue on my S plus. Have a listen...
Post by: PhillyArcade on September 14, 2022, 12:49:16 PM
I would try swapping the sound generator IC (U55) with a known working one and see if that resolves it.
If we ever meet my friend I owe you a beer! :cool_thumb_up: That did it! Swapped out U55 and she is singing her song while the reels spin! I added a socket as I always do when swapping out IC's. The next guy in 20 some years will thank me. :D Thanks again for the tip! :applause:
Title: Re: Sound issue on my S plus. Have a listen... *UPDATE Fixed!* Stop on in...
Post by: Tilt on September 19, 2022, 08:08:02 AM
Well I'm glad to hear it, but shocked after seeing your pictures. Apparently I was looking at a different S+ schematic (16Mhz MPU) than the one you have (10MHz). On a 10Mhz board the sound generator is u49 and it is in a socket. On a 16Mhz board it's U55 and soldered. So the chip you changed wasn't the one I was referring to, but by blind ass luck apparently was the one that was causing your problem. Anyways, I'm glad it's working :applause:
Title: Re: Sound issue on my S plus. Have a listen... *UPDATE Fixed!* Stop on in...
Post by: Stayouttadabunker on September 19, 2022, 09:48:24 AM
I'm wondering what chip he changed out? It's not the sound generator "AY" chip, is it?
Title: Re: Sound issue on my S plus. Have a listen... *UPDATE Fixed!* Stop on in...
Post by: PhillyArcade on September 19, 2022, 12:51:40 PM
Well I'm glad to hear it, but shocked after seeing your pictures. Apparently I was looking at a different S+ schematic (16Mhz MPU) than the one you have (10MHz). On a 10Mhz board the sound generator is u49 and it is in a socket. On a 16Mhz board it's U55 and soldered. So the chip you changed wasn't the one I was referring to, but by blind ass luck apparently was the one that was causing your problem. Anyways, I'm glad it's working :applause:
hahaha I just spit my ice tea across the room reading that!! Wow! Well that IC must do something in the sound circuit :Scratch-Head: I've been told the blue volume knob on top of the board means 10 Mghz so you are correct there. I don't have a schematic for one of these PCB's yet so I'm not sure what U55 is but you might want to play the lottery tonight. lol I played the heck out of it last night after posting and the audio has been perfect on it! Like he said I wonder what U55 does in the sound generator. I guess it's even possible the PCB wasn't seated perfect on the motherboard. I did find a quarter laying down there between the MB and CPU. I have the plastic cover on the MB so I don't think the quarter was causing any issues. I haven't had the CPU board out since I changed the battery a year ago. So it's not like I had it out recently and then the sounds started acting up.. We'll mark this up in the strange column! If anyone knows what U55 is please chime in!
Title: Re: Sound issue on my S plus. Have a listen... *UPDATE Fixed!* Stop on in...
Post by: Tilt on September 19, 2022, 01:17:14 PM
U55 on the 10MHz board is a CD4021 8 stage shift register. It's used in the clock circuitry, so it could have had an effect on the sound, but I'd expect it to cause other problems too. The sound generator is the AY chip that bunker asked about and is at U49 on the 10MHz board. That's the one I meant for you to change. All is well than ends well as they say :applause:.
Title: Re: Sound issue on my S plus. Have a listen... *UPDATE Fixed!* Stop on in...
Post by: PhillyArcade on September 20, 2022, 08:43:15 AM
U55 on the 10MHz board is a CD4021 8 stage shift register. It's used in the clock circuitry, so it could have had an effect on the sound, but I'd expect it to cause other problems too. The sound generator is the AY chip that bunker asked about and is at U49 on the 10MHz board. That's the one I meant for you to change. All is well than ends well as they say :applause:.
Interesting for sure! Well I played it again yesterday for about 5 hours and it was on longer and not a sound glitch so I'll mark it down as fixed! :D Thanks again for your input! :applause:
Title: Re: Sound issue on my S plus. Have a listen... *UPDATE Fixed!* Stop on in...
Post by: Tilt on September 20, 2022, 12:33:36 PM