Light meaning and fix
Star TSP100IIIW Ready and Error LEDs Blinking Every 1/2 Second
On the Star Micronics TSP100IIIW, the Ready and Error LEDs both blinking at 1/2 second intervals means a printer head thermistor error.
On the Star Micronics TSP100IIIW, the Ready and Error LEDs both blinking at 1/2 second intervals means a printer head thermistor error.
What it means
The printer detected an abnormality related to the print head temperature sensor.
Device details
| Device type | Receipt printer |
|---|---|
| Brand | Star Micronics |
| Model | TSP100IIIW |
| Light name | Ready LED and Error LED |
| Light location | Operation panel |
| Color | Ready/Error LEDs |
| Pattern | Both blinking at 1/2 second intervals |
| Severity | danger |
| Last verified | 2026-05-02 |
What to do first
Turn the printer off and on once. If the same error returns, contact the seller or service provider.
- Turn the printer off.
- Wait briefly.
- Turn the printer back on.
- Check whether the same LED pattern returns.
- Do not keep forcing print jobs.
- Contact the seller or service provider if the error remains.
When this can be normal
This is not a normal ready state.
When to stop troubleshooting
Stop if the same error displays again after power cycling.
Parts or products that may help
Only replace parts when the light pattern and official guidance support it. Some lights indicate setup or software states, not broken hardware.
- No replacement part is recommended from this light pattern alone. Troubleshoot the device state first.
FAQ
What does both LEDs blinking every half second mean?
Star says it is a printer head thermistor error.
Should I keep printing?
No. Turn it off and on once, then contact service if the error returns.
Is this a paper issue?
No. This LED pattern is tied to a print head temperature sensor error.
This guide is based on: Star Micronics TSP100IIIW LED Display.
Source type: official_manual. Confidence: verified. Last verified: 2026-05-02.
Thermal receipt printers can have hot printhead parts. Follow official safety guidance.