Receipt Printer Won't Print: Paper Roll, Thermal Printhead, QR
The cashier presses "Pay", but the printer outputs blank paper, a faint strip covered in streaks, or jams the receipt halfway through. In most cases, it's not a circuit board failure, but a paper issue: wrong side, wrong size, or a dirty printhead. Let's break it down step by step — from "where's the ink?" to legally going completely paperless.
1. Symptom → Cause → Section#
| Symptom | Probable cause | Section |
|---|---|---|
| Prints blank paper | Thermal paper loaded upside down | §3 |
| Receipt jams, paper feeds crooked | Loading error, cover not latched, roller clogged | §3 |
| Faint print, gray streaks | Dirty/worn printhead, cheap paper, eco mode | §4 |
| "Out of paper" with a full roll | Usually paper loaded upside down or clogged sensor, see ATOL errors | — |
| QR code not scanning with tax app | Low print density, printhead wear, small QR, damp paper | §6 |
| Want to avoid using paper entirely | E-receipt instead of paper — not always allowed | §7 |
2. Inkless Thermal Printing: How It Works#
A receipt printer has no cartridge or ink ribbon — only the heating array of the thermal printhead. Paper is coated with a heat-sensitive layer that darkens from spot heating; this is the "printing" process. This leads to two conclusions: looking for a cartridge is useless (if it fails to print, the cause lies in the paper roll or the printhead, §3–§4), and the roll has strictly one printable side.
Fingernail test. If it is unclear where the thermal layer is (e.g., a roll without packaging), scratch the paper firmly with your fingernail — friction heats the layer locally, leaving a dark mark on the thermal side, much like a pencil line. There will be no mark on the reverse side.
3. Paper roll loading: upside down, jamming, or skewed#
Blank printing and paper jams usually stem from the same careless loading, just with different symptoms. The correct sequence:
- Completely open the compartment cover and remove the remains of the old paper roll.
- Insert the roll without skewing — the edge should be flush, the paper running parallel to the guides, and the thermal coating (fingernail test from §2) facing the printhead, not away from it.
- Pull the edge out through the tear slot without slack or getting caught under housing parts.
- Close the cover until the latch clicks — an improperly closed cover fails to press the paper against the printhead and platen roller: printing comes out blank, and the paper sways and jams during feeding.
- If it jams consistently even after neat reinstallation — wipe the platen roller; paper dust accumulates on it.
4. Faint printing or streaks#
- Print density. Printer/POS settings often include a "darkness" or "eco mode" setting — if it was lowered to save paper, set it back.
- Paper quality. Generic thermal paper with an uneven coating produces weak contrast at high speeds — switch to paper of the same size from a reputable supplier.
- Dirty printhead. Dust and adhesive residue from old paper blur the print. Clean only with the power turned off and the printhead cooled down, using an alcohol wipe or cleaning pen — no water or abrasives.
- Printhead wear. Streaks in the same spot that cleaning cannot remove indicate burned-out elements on the printhead array; check the expected lifespan in the manual — beyond that, replacement is required.
5. What thermal paper is needed: 57 vs 80 mm, diameter, core#
| Parameter | What it affects |
|---|---|
| Width: 57 or 80 mm | Determined by the model, not chosen by eye: narrow paper sways in a wide compartment and prints crookedly |
| Maximum roll diameter | A roll that is too large prevents the lid from closing or rubs against the housing |
| Core diameter | Smaller than standard — the roll wobbles on the spindle, causing the paper to feed unevenly |
Exact values can be found in the POS or printer manual (“consumables”). Using the wrong paper is a direct cause of jams (§3) and false “out of paper” alerts with a full roll.
6. QR Code on the Receipt Is Not Readable by the "Receipt Check" App#
The reasons overlap with §4: low print density merges adjacent QR modules into a smudge; a worn printhead knocks out dots inside the code; a QR scale that is too small in the settings drops the module size below what the camera can read; receipt paper stored in a humid place or near a heat source loses contrast after printing. Test by scanning immediately after printing, not a day later — this makes it easier to tell whether the issue is with the printer or storage.
7. Can You Go Paperless? Electronic Receipts Under 54-FZ#
Yes, but with a condition. The customer may before the payment is processed provide a phone number or email and agree to receive an electronic receipt — the fiscal document is still generated in the FN and sent to the OFD, only the delivery method changes. If contact details are not provided, a paper receipt is mandatory — this is the customer's right, not the merchant's choice.
8. Example#
Coffee shop with a smart terminal: after replacing the paper roll, the printer started outputting blank receipts. A scratch test showed that the thermal coating was on the outer side of the roll, while the inner side was pressed against the printhead when loaded. Flipping the roll over restored printing without calling a service technician.
9. How to do this in Cenaly#
- The printer connects via Cenaly Hardware Bridge; the Equipment section shows its status, while "Equipment Checks" allow a test print immediately after replacing the paper roll or cleaning the printhead — without generating an actual fiscal receipt.
- If the printer stops working, Cenaly POS continues accepting orders — receipts are printed retroactively after the repair, and reconciliation is available in POS → Receipts. In case of a prolonged breakdown, see correction receipt on POS breakdown.
10. Frequently Asked Questions#
How to determine the paper side without packaging or markings? Nail test from §2: the thermal layer darkens from friction, while the regular side does not.
Can I clean the print head with a hand wet wipe? No — only an alcohol wipe or a cleaning pen, and only when the power is turned off and the print head has cooled down.
Is "Out of paper" with a full roll also related to the paper roll? Often yes: an inverted paper roll or a dirty sensor produces the same symptom; see "ATOL Errors", §5.
Is a customer entitled to receive a paper receipt if they don't have a phone on hand? Yes — if contact details for an electronic receipt are not provided before payment, the seller is obliged to issue a paper one.
Related articles: ATOL errors · SHTRIH-M errors · Cenaly Hardware Bridge · correction receipt upon POS breakdown · how to choose a POS
This material is for informational purposes only and does not replace consultation with a service center or equipment manufacturer. Primary sources: technical documentation for fiscal printers and POS terminals, Federal Law No. 54-FZ "On the Use of Cash Register Equipment", guidelines from the Federal Tax Service (kkt-online.nalog.ru).