Welcome to the wonderful world of system 6.

To stay happy in this world your attendance at the following web sites is recommended:

http://pinball.flippers.info/system6resources.asp
http://www.firepowerpinball.com/
http://pinwiki.com/wiki/index.php?title=Williams_System_3_-_7

To answer your specific question, yes there are two 4A slo-blow fuses located on the sound board. However, the chances are 99% that this is not your problem and even if a fuse is blown, you have to track down the reason why it blew in the first place because if you just replace it, it will likely blow again.

To insure that your sound works correctly, chances are you will need to change one or more ROMs, sockets and connectors.

For now, check your fuses, reseat your ROMs, make sure none of the pins break off and hope for the best.

Good luck!

viperrwk

Make sure J4 & J5 aren't loose on the soundboard (volume & speaker wires).
Check that the wires didn't get smashed by the playfield being raised & lowered?
Note... there are multiple volume controls... on the board and the remote down in the cabinet. Set them all to the middle to start with.

Greg

Pull and reseat the ROMs. Check the pins on theROMs. If they're black they potentially will break off and likely need replacing along with the ROM sockets.

viperrwk

Here's why the sockets need to be changed.

This
http://www.siegecraft.us/the_siege_blog/blog/2011/12/why-rn-sockets-also-suck.html

and this
http://www.siegecraft.us/the_siege_blog/blog/2011/12/box-o-boards-scorpion.html

viperrwk

See my previous post. Sorry to rain on your parade. That "fix" is short-lived and without changing the sockets the problem will return.

viperrwk