Our printing is becoming lighter. How can we fix it?

good

Check the availability on ebay?

you need to configure it in software that you are using, to answer this question need some more information and screen shots, like..which os and which software you are using. and more print screen for printers and your software option print screen.

Our Star TSP700II leaves about 1/4 inch of unused paper on the roll when the error light comes on and the printer stops printing. Is there any way we can make an adjustment so that we're not wasting so much paper?

You need to check the Microsoft Hardware compatability list to see if you printer is supported. If it is listed ... you are in good shape ... if it is not listed ... you are not so lucky ... find it here: http://www.microsoft.com/windows/compatibility/windows-7/en-us/?CMXID=ef_sem&semid=ef_GGL_0e0f44f2263d9fb99014efc1c39272bb&WT.srch=1&ef_id=2437:3:s_66bea0d11c63cfbddec4c4d9f702c38a_5518858882:TJf9wgqoEEQAABCz7uAAAAWK:20100921003514

you might need to fiddle around with the usb virtual printer port configuration , when you add printer. when adding a printer, uncheck the install automatically tick box, then on the NEXT page click on the drop down list of "use the following port" and try virtual port. it might work.

try hooking it up to another computer that is not having this problem if the printer works try reinstalling the driver on the other system

I have a problem with some TSP700II printers that print extremly slowly. I have most recently downloaded and installed...

try cleaning the print thermal bar with rubbing alcohol

It'll be the BAUD rate, try changing it in the till software to 9600 or 128200