Anyone know anything about L46H1 Goodview billboards?

[PMSM]

I'm trying to find a schematic my boss saw, years ago, for an electronic billboard we have in our museum. He wants me to rewire it so we can use external powered speakers instead of the 5 watt onboard speakers it came with. Has anyone worked with these devices before, or seen said schematic?

 

[hevans1944]

All I know is what Google reveals: a Chinese Light Box model L46H1 built by Shanghai Goodview Electronic Co.,ltd. Is the image below representative of what you have? Try contacting the vendor directly using information on this web page.

I am curious as to why anyone would need a schematic to wire in external speakers... are not the wires to the built-in speakers readily available? Maybe your boss is trying to determine if you have any electronic skills. Do you?