Quoted from reynolds531:""I have a “player’s condition” Funhouse that I am thinking about a more or less full restore. One of the issues that I am having is that I cannot turn the volume down and there is some baseline static heard on the speakers. I did some research on Pinside about this problem and the sound board is the likely problem (failing digital pot or amp?). I did the easy stuff first (reseated ribbon cables, factory reset, volume override to “yes”). When I look at my machine it has an extra board (A13502) that runs from the sound board to the MPU. Apparently it is the “sound overlay board” from System 11 and was found on a few Funhouse and Dr. Dude machines. The FH manual that came with my machine does not include the A13502 board in the back board parts schematic. Could this extra board be causing any of the sound problems? Will I need this board if I rebuild/replace the sound board?""
I posted the above in the alpha-numeric topic last week and I didn’t get many replies. I am hoping that the Funhouse specific forum will be more helpful. I have done some more homework and I have figured out that I have a prototype FH (side rails, extra STEPS switch, raised start button). It has the A13971 sound board and the A13502 board. What needs looking at to fix the volume control?
I found the answer about using the A13502 board on Pinside and it is a bit of a work around. If I can figure out the volume and static problems with boards I have I will just use them.
On a separate note: with all of the Mirco playfield problems where can I source a new Funhouse playfield? I would really rather not order from Marco given all of the issues with his playfields. I did reach out to Mr. Kruzman about having him work his magic on a Mirco FH playfield.
Your volume knob is in the cabinet on the left side by the tilt bob if you didn't know. You cannot use the up/down buttons they do not work with your machine. You also cannot go above a certain code level. It is possible you have issues with a board, but the volume knob gets scratchy and flaky over time and need cleaned or they cut out, etc. If you have not already looked into this, that is where I would start. I will check my manuals to see if I have the Sys-11 board schematics but I really doubt the board is your issue.
Funhouse was made around the same time they were changing backend systems. The protos/samples and probably the first 100 or so use the old analog system (Sys-11). WPC was the newer digital version that uses the volume buttons.
Since you say you have the extra STEPS target congrats. I don't think very many of those were made. However...that does kind of put a damper on your plan to get a remake playfield. The remakes are not going to match yours, but on the plus side, I think all of the early games have some sort of clear coat or mylar on them. If it needs work you would be better off sending it out to get it repaired and clear coated.
You can find more information and pdf's of manuals for the soundboards here
https://www.ipdb.org/machine.cgi?id=966
The more I think about this (because I also have an early game) anyone aware of anyone converting from Sys-11 to WPC? Everything seems to be there to do it, just maybe change out the boards and upgrade the ROMS?