7 Flashes but mute?

[Completist]

ok so i don't know if i understand this one. Have two F2k's and both work. One boots up as expected with 7 flashes and the 7 audible tones. The other only gives me 7 flashes but no tones and this bothers me. Games plays fine and i have sound and speech. I didn't look to see if this was set by a jumper but can't see it if the game is booting up still.

Any thoughts? I haven't dove into it really but maybe someone has experienced this before.

Thanks!

 

[Completist]

Ok so far here's what i have figured out:

• It's not just the startup boings that are not present. I'm missing the ingame background sound (not triggered by switches etc). So thats's a hint i think...
• The issue lies within the SB300 sound board. I used a process of elimination to rule out the MPU, both ribbon cables and the connected Vsu-100 speech board.
• I replaced the 34 pin .100 header. Tested my solder joints for bridges and connectivity between the new pins and the termination points on the board as per the scematics. No change.
• Swapped the socketed 6840 programmable timer from a working board. Thats not the issue either.

Will keep plugging away. I have two fully functioning SB300's for the two F2K's but really want to get the spare working properly. Think i'll take a closer look at the re-capping that had been done in the past. Any other suggestions always welcome.

 

[Completist]

found this but don't think it's a culprit. But whoever replaced Cap C8 tore the pads off the top side. Not that i'm not capable of doin that But on the back side the solder looks fine and dmm says its connected to where its sposed to go when i follow the trace.... and i don't see anything coming off the top side off that component.



Also noticed that all chips are Motorolla cept u16 and u17. Thought maybe they had been replaced but looking at the other boards they have the same types.

 

[spiroagnew]

I had quiet background sounds on my Catacomb at strange intervals during gameplay--depending on other in-game sounds being played the volume would come and go.

I popped in a new 5101 RAM chip on my MPU and it cleared up the issue completely. This is a well documented fix online--the RAM chip clearing up missing, soft and distorted sound issues. Worth a shot for you.

 

[Completist]

Thx i'll add those 5101's to my shopping list. Socketed already so it will be an easy test - even if it doesnt solve that issue may solve others i'm not even aware of yet lol

 

[spiroagnew]

I think I may have a few 5101s hanging around if you want to make the drove to Burlington.

Sent from my SM-G920W8 using Tapatalk

 

[Completist]

Thanks i'll send a pm. Ed is out of stock on those at the moment...