On Windows, install your printer with Epson's driver, not Microsoft's. Download it from Epson's website for your model. If Windows set the printer up by itself with a Microsoft driver (Windows Ready Print or Microsoft IPP Class Driver), it may still print, but the tool often can't read or reset it over USB. How to get the Epson driver back.
The short answer
The L120 and L121 are small printers with just two lights: power and error. When both flash at the same time, Epson’s L121 guide says an ink pad is nearly full or full. That is a counter error. Nothing is broken, and you can read the counter for free.
But be careful. With only two lights, a paper jam can look similar. Epson lists power flashing with error flashing for a paper jam too. So always check for paper first.
What each light pattern means
The meanings below come from Epson’s user’s guides for the L120 and the L121 (links in Sources). Both guides show the same two-light panel.
| Lights | What Epson says it means | Can VNIT Reset Tool fix it? | What to do |
|---|---|---|---|
| Power on | The printer is on. | Not needed | Nothing. |
| Power flashing | The printer is busy. After you fill the ink for the first time, it flashes for about 20 minutes. | Not needed | Wait. Do not switch off or cancel. |
| Power + error flashing at the same time | An ink pad is nearly at, or at, the end of its life (L121 guide). | Yes (main pad counter) | Check for paper first. Then read the counter and reset it. |
| Power flashing, error flashing | Paper may be jammed. If it continues, there may be a printer error. | No | Remove the paper and press the cancel button. Switch off, look inside for paper or objects, switch on. |
| Power flashing, error on | No paper, or several sheets went in at once. | No | Load paper and press the cancel button. |
| Power on, error on | The first ink charge may not have finished. | No | Switch off and fill the tanks as the setup sheet says. |
| Power off, error on | A firmware update failed. | No | Update the firmware again over USB. |
Note: Epson’s L120 guide does not list an ink pad pattern at all. The L121 guide does, and it shows the same two-light panel as the L120.
Paper jam or full ink pads?
Because the two patterns look alike, work through these steps:
- Switch the printer off. Open it and look for paper, torn pieces or small objects.
- Switch it on again and press the cancel button.
- If both lights still flash together, read the ink pad counter (next section). The number tells you for sure.
The printer driver on your computer may also show a message, such as “The printer’s ink pads are at the end of their service life”. That confirms it is the pads.
Is it the ink pads? Check for free
- Download VNIT Reset Tool and run it on a Windows computer.
- Connect the printer with a USB cable. The L120 and L121 have no Wi-Fi, so USB is the only way.
- Press Check Printer. Reading is always free.
On the L120 the tool shows one counter: Main pad.
If it is at 90% or more, you can run the free trial once per printer. It lowers the counter to 80%, which clears the error. A key costs US$6 and resets the counter to 0%.
After any reset, switch the printer off and on again. The printer only reads the new counter when it starts. If the lights keep flashing, see the error is still there after a reset.
A reset only changes the number. The pad itself may be soaked. Read what to do with the ink pads after a reset before you print a lot again.
Errors a reset does not fix
- Paper jam. Remove the paper gently and press cancel.
- Something stuck inside. A clip, tape or packing foam can block the print head. Remove it and switch off and on.
- Carriage problems. If the print head cannot move, a counter reset will not help. Clear the path, or take the printer to a technician.
- First ink charge not finished. Follow the setup sheet.
- Printers with a maintenance box. Some other Epson models use a replaceable box instead of fixed pads. The L120 and L121 use fixed pads. See reset or replace a maintenance box if yours has a box.
Models in this family
- Epson L120 — Main pad counter.
- Epson L121 — same two-light panel as the L120. Ask us on WhatsApp before you buy a key for this model.
Not covered here: the Epson L1110 has separate ink and paper lights. See Epson L3110 / L3150 blinking lights. The Epson L130 has three lights (power, paper, ink): see Epson L130 lights.