Epson lq-2070 dot matrix... replaceable electronics?

Hello, and thanks in advance for any advice. I am to the point of confusion, so once again I turn to the windrivers crew for help...

We don't really repair printers to much. either it works or "buy a new one", but this is for a business customer, and I HAVE NO IDEA WHAT I AM DOING!

This printer prints part of a long (more than 1 page) doc and then the print head goes to the right, printing stops, and the pause and paper out LEDs come on. Rebooting the printer will enable me to reprint, but it just stops again midway.
It prints test pages OK. Also, there are two LEDs for "tear off/bin" which will not illuminate--hitting the button to cycle through the combos only causes the printer to pull the paper in and push it right back out. I dont even know what "tear off/bin" is supposed to do when feeding paper directly in from the back but i don't think it does this. ?

As you can see, what i know about dot matrix printers fits neatly on a floppy with room to spare. The online help is not telling me what i am looking for either.
I think the printer's electronics may be to blame, and i've heard it said that this may be a replacable component? Is this true?
What else can i do? Any resources you would recommend?

Thanks again!

First mistake: telling a customer you are going to fix something when you really have no clue. Bad idea, you got the customer's hopes up by saying you could fix their precious antique, now you're screwed and you've got one annoyed customer. Better to be honest and refer the work elsewhere.

Anyway, enough of today's life lesson. Have you tried hooking this printer up to other computers? Tried a new parrallel cable? Sometimes they go bad.

To salvage this situation, I would do everything short of tearing it apart, then tell the client that you can't fix it, it will have to be done by a specialist. And it would cost more to repair it than to purchase a new one... Hopefully they can swallow the news