Breath Test Printer Prints Faint, Blank, or Garbled Output

What's happening

Print problems on a breath test instrument usually come from one of three places: the thermal paper itself, the printer's internal battery, or — if you're printing a report from a PC rather than directly off the instrument — the Windows print pipeline. The fix is different for each, but the first one costs nothing and takes ten seconds, so it's always worth checking first.

Try these in order

1. Check the paper orientation. Thermal paper only prints on one side, the coated side. If a roll was just changed and the output is blank, faint, or garbled, open the printer and flip the roll so the coated side faces the print head. This alone accounts for a large share of "printer stopped working right after I changed the paper" reports.
2. Confirm the paper is actually thermal printer paper for your instrument. A mismatched or non-thermal roll will feed but won't print correctly.
3. If the printout is consistently faint or spotty rather than blank, suspect the printer battery. A printer that won't hold a charge overnight, or that starts printing faint or spotty after a day or two unplugged, usually has a battery reaching end of life rather than a paper problem. Leave the unit on charge overnight and try a fresh printout before assuming a battery issue, but if it repeats after a full charge, it's the battery.
4. If nothing prints at all and the paper orientation and battery are both fine, the fault is more likely internal to the printer connection or module rather than something field-correctable — see below.

If it's a battery or connection issue

A printer battery that won't hold a charge is field-replaceable. We can ship a replacement battery for you to install, or take the whole unit in for repair if you'd rather not do the swap yourself. If the printer isn't producing any output even after a full charge and a confirmed-correct paper roll, that generally points to an internal printer connection fault, which needs the unit in for service.

PC-side report printing error (Crystal Reports / PEOpenPrintJob)

If you're printing a report from a Windows PC rather than off the instrument directly, and you get a popup error referencing something like PEOpenPrintJob error and a temporary report filename (for example RptTmpI3.rpt), that's a Windows printing issue, not a data problem. Work through these in order:

1. Close the reporting application completely.
2. Confirm your Windows default printer is online — print a normal Windows test page. If that fails, fix the printer connection or driver first before going further.
3. Restart the Print Spooler service: press Windows+R, type services.msc, find Print Spooler, and restart it.
4. Clear stuck spool files: stop the Print Spooler service, delete everything inside C:\Windows\System32\spool\PRINTERS\, then start the spooler again.
5. With the application still closed, delete any leftover temporary report files (named something like RptTmp*.rpt) from the application's working folder.
6. Reopen the application and try printing again. If it still fails, try setting a different default printer, or "Microsoft Print to PDF," to confirm the report itself renders correctly, and consider reinstalling or updating your printer driver.

This is a local Windows printing problem, so your IT department can usually work through these same steps if you'd rather hand it off.

When to call us

• Paper orientation, a fresh roll, and a full battery charge don't resolve it.
• The printer won't produce any output and you've ruled out paper and battery.
• You want us to ship a replacement printer battery, or you'd rather send the whole unit in.

Call (513) 891-0868 or email service@fosterinstruments.com.