Receipt Printer Troubleshooting: 9 Faults and Real Fixes

A receipt printer fails at the worst possible moment, with three customers waiting and nobody senior on the floor. The reflex is to swap the cable, reinstall the driver, then order a replacement. In most cases the fault is much smaller than that: a roll loaded coated side down, a USB class setting the till software cannot see, or a DHCP lease that moved overnight. This receipt printer troubleshooting guide runs the checks in the order that finds the cause fastest, and tells you at each step which result proves the diagnosis.

Which fault do you actually have?

Start with the self test. It runs entirely inside the printer, so a good self test clears the hardware and moves the problem to the cable, the driver or the software. On Epson TM printers, close the paper cover, hold the Feed button and switch the printer on. Keep holding until printing starts. Bixolon SRP models use the same idea with the Feed button. The printout gives you the firmware version, the interface in use, and the maintenance counters including print head running length and autocut count.

Why does the printer feed blank paper?

Thermal paper is coated on one side only. If the coated side faces away from the print head, the printer behaves perfectly and produces nothing. This is the single most common receipt printer fault we see, and it costs nothing to rule out: scratch the paper with a coin or a fingernail. The side that darkens is the coated side, and it must face the head. In a clamshell printer such as the Epson TM-m30III (C31CK50112) the coated side faces up as the roll sits in the well and the paper tail comes off the top of the roll.

The second cause is paper that is not thermal at all. Plain 80 mm rolls bought as a bargain will feed and cut and never print. The third is a genuinely dead head, which the self test will show as blank output on paper you have already proved is thermal. At that point the printer needs service, not another roll. Stocking a known grade from our thermal paper rolls range removes two of those three causes permanently.

The self test prints but the till software does not

This split is useful, because it means the mechanism, the head and the power supply are fine. Work through the connection instead.

On USB, Epson TM printers can present themselves in two ways: a vendor defined class, which is the factory default, or a standard printer class. The Epson Advanced Printer Driver and OPOS expect the vendor class. Software that talks to a generic Windows printer queue often expects printer class. If the printer appears in Device Manager but not in the till software, or the other way round, that setting is the first thing to change. The Epson technical reference guide lists the memory switches and the utility used to change them.

On serial, the printer and the software must agree on baud rate, data bits, parity and flow control. The self test prints the settings the printer is actually using, so compare that printout with the port settings in the POS configuration rather than guessing. Serial models such as the Bixolon SRP-330III (SRP-330IIISK/BEG) hold these in switch settings that survive a power cycle, which is why a printer that worked for two years can fail after someone resets it to defaults.

On Ethernet, the fault is almost always addressing rather than the printer. See the network section below.

Why will the cash drawer not open?

The drawer is not a computer peripheral. It plugs into the printer, and the printer fires a 24 V pulse down the drawer kick cable when the POS software sends the ESC/POS drawer command. Three things break this, in order of frequency.

• The software sends the pulse to drawer 1 while the cable sits in the drawer 2 position, or the reverse. Both are valid, and only one matches your wiring.
• The cable is plugged into the network port. The drawer connector and an RJ45 socket look similar at counter height, and a drawer cable in an Ethernet port does nothing at all.
• The pulse duration is too short for the solenoid in a heavier drawer. Increasing the on time in the POS printer settings fixes drawers that click but do not release.

Test the printer on its own using the manufacturer utility before touching the POS configuration. If the utility opens the drawer, the hardware is sound and the fault is in the software profile. If it does not, swap the cable first, then the drawer. Our front opening cash drawers ship with a standard kick cable, and a spare cable is cheaper than an afternoon of diagnosis.

Why does a network receipt printer disappear overnight?

A printer configured by DHCP will keep its address only as long as the lease holds. Close the shop for the weekend, and the router hands that address to a tablet on Monday morning. The POS still points at the old address and reports the printer as offline, even though it is powered, quiet and perfectly healthy.

Two fixes work. Set a static address on the printer, outside the DHCP pool, or reserve the address on the router against the printer MAC. The MAC is printed on the self test. Reservation is better in a shop with several tills, because it keeps every address in one place instead of in nine printers. Whichever you choose, write the address on a label on the printer itself. Models such as the Epson TM-T88VII (C31CJ57132) and the Bixolon SRP-350plusV (SRP-350PLUSVK/BEG) both hold a static configuration through a power cut, which a DHCP lease does not.

Why is the print faded, and is the head finished?

Faded print has four causes and only one of them is expensive.

Raising density is not free. Higher density means more heat per dot, which shortens head life and slows printing. If a normal setting on decent paper is readable, leave it there. Cleaning kits and spare platen rollers sit in POS printer accessories, and a five minute clean often restores a printer that looked ready for replacement.

The cutter jams: replace or repair?

Autocutters are rated in cuts, not in years. The Epson TM-T20III cutter, to take a published figure, is rated at 1,500,000 cuts. A shop printing 300 receipts a day reaches that in roughly thirteen years, so a cutter failing after eighteen months is not worn out. It is jammed, or it is fighting the paper.

Check three things. Roll diameter must be within the printer specification, since an oversize roll drags and pushes the cut off centre. Paper dust builds up under the blade and needs blowing out, especially with recycled grades. And a half cut left uncleared will jam the next one. Most models have a manual release: open the cutter cover and turn the knob back to the home position before you try again. The self test tells you the real cut count, so you can see at a glance whether the mechanism has done any meaningful work.

The kitchen printer that keeps missing orders

Kitchen printing is a different problem from counter printing, and thermal is often the wrong technology for it. Heat, steam and grease darken thermal paper, and a ticket that is legible when it prints can be unreadable by the time the dish is plated. Wi-Fi adds a second failure mode, because a printer at the back of a kitchen sits at the edge of the signal and drops off during service.

Both problems have the same answer: a wired impact printer such as the Epson TM-U220 (C31C513057). It prints with an inked ribbon onto plain paper, which survives steam, and a cable does not roam. It is slower and noisier than a thermal printer, and in a kitchen neither of those matters.

Common questions

How do I run a self test if I do not have the manual? Close the paper cover, hold the Feed button, switch the printer on, and keep holding until it prints. This works on nearly every Epson TM and Bixolon SRP model.

My printer prints a receipt but cuts in the wrong place. Why? The software is sending a cut command plus its own feed, or the receipt template ends with too few blank lines. Adjust the trailing feed in the POS template, not on the printer.

Can I use 58 mm paper in an 80 mm printer? Usually yes, with the supplied guide plate, and you must tell the software the narrower width. Note that on some Epson models the change is intended to be one way, so check the specification before converting a printer you may want back at 80 mm.

The receipt is printed but nothing was recorded in the accounting system. Is that a printer fault? No. The printer is the last step, not the record. Check the POS integration and the fiscal or accounting log separately.

Is it worth repairing a five year old receipt printer? A platen roller, a cutter or a power supply is worth replacing on a working printer. A worn print head on a model at end of life usually is not, because the part price approaches a new unit.

Why does the same receipt look different on two identical printers? Density and speed settings are stored per printer and are not copied when you clone a POS configuration. Compare both self tests.

Where to go next

Most receipt printer faults are paper, addressing or configuration, and all three cost nothing but ten minutes to eliminate. Work through the self test first, then the connection, then the software, and only then reach for a replacement. If the printer really has reached the end, the current thermal and impact models sit in POS receipt printers, with matching rolls, kick cables, cleaning kits and spare rollers in POS printer accessories. Keeping one spare roll grade and one spare drawer cable per site prevents most of the calls described above.