Hi,
For your query re. the plug fuse, a 3A fuse isn't really enough, due to the initial load as the machine starts up (I got a service call once, to a Flintstones which wasn't powering up. Health & safety had just visited the location, and changed the plug fuse to 3A. This had blown.). There's a (4A) fuse for the incoming mains inside the machine, so the plug fuse is only exclusively covering the mains lead.
As for the language settings, this is a fairly frequent situation. The 'WPC' board-set games have at least three languages for text, English, French and German. If the seller didn't actually show you how to obtain English text, then use that recall of subtitled French fillums (did you see 'Les Flics'?) to get into the Adjustment menu and select English instead;
- Open the coin door and press the 'Enter' button
- Use '+' or '-' to select 'Menu Reglage' ('R') and press Enter
- Now select R.1 (standard adjustments) and press Enter
- Scroll through to the language selection, R.1.21? which will be 'Francais'
- Press Enter, the current value will flash, allowing a change
- use +/- to select English (or Deutsch, if you prefer)
- Press Enter to make the alteration
while you're in this menu, find 'Minimum Volume Over-ride' and change it to 'Yes'.
If the game has reverted to French text, then it's probably lost any other alterations too, such as Free Play. If you'd like that feature, it's an item in Pricing Menu, '#.3'
The factor which selects French as a default is the pattern of connections made in an area of the Cpu board, next to the unused 'Display' connector, marked with the outline of a chip and some 'W##' identifiers. W was the sign of a simple wire linkage between circuit traces, and some of these (14 to 18, AIR) are used to select the territory that a game was set for at the factory. As Carl says, there may be an 8-way switch block fitted to the board allowing a simple correction, but if there are zero-Ohm links there (White with black band) one will be missing for French. Apparently having two or more missing sets a USA default.