I believe that if you perform a "Self-test" it clears the print buffer on an Epson Ptr. Just hold down the Paper Feed button when you power on the printer, that prints out the current printer settings, pressing the paper Feed a 2nd time will initialize a print test pattern. After that completes, the ptr lights should appear normal and the print buffer is cleared. You can use the printed printer settings to compare it to other "like" ptr's rather than examine each ptr's Dip Switch settings.
Self Test multiple ptr's and compare the print outs as the message you had "receive buffer full" may be the default and not necessarily indicative of an existing problem.
Intermittent print can also be caused by having multiple remote ptr's assigned with the same ID #. IE: You have two remote ptr's whose Dip switch settings (Micros IDN Interface-not the Epson Dip Switches) are set identically thereby creating two #1 ptr's. Printing will toggle back & forth between ptr's casuing delays and print buffer full errors.
You mentioned you had multiple "like" ptr's. Swap/exchange the problem ptr around to another location to see if the problem follows the ptr or if the problem remains at the original location. Ihis could further indicate if you have a ptr problem or a possible wiring problem
Also examine the connections for damage or corrission. It is common for remote ptr connections to become soiled and/or wet from liquid or steam. Moisture damage can take months to appear. Visually examine each connector, look at each plug as well as the connector box, if you see bent pins or green corrosion on the connectors, replace asap.
ALWAYS ALWAYS ALWAYS disconnect and reconnect all connections when trouble shooting intermitent connection issues with printers.
Good Luck!