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Project Notes

#733 TS-BN55 Digital Oven Thermometer

Examining and fixing the TS-BN55 Digital Oven Thermometer



I purchased the TS-BN55 Digital Display Electronic Thermometer some time ago. It appears to have been superseded by newer models that may have largely the same hardware but upgraded firmware (and perhaps a higher resolution LCD).



  • Easy to use and safe for food.
  • Light weight and portable food thermometer.
  • Large easy-read LCD triple screen display with thermometer,timer and 12/24hr clock.
  • Switchable °C and °F unit.
  • Thermometer / timer alarm function.
  • High-low temperature alarm function.
  • A great helper for food health and safety.


  • Material: Stainless Steel + ABS
  • Measuring Temperature Range: 0°C~300°C (32°F~572°F)
  • Temperature Accuracy: ±1°C (0°C~100°C), ±1.5°C (101°F~300°F)
  • Temperature Display Resolution: 0.1°C (0.2°F)
  • Timer Range: 99MIN 59SEC
  • Unit: °C / °F Switch
  • Power supply: 2 × 1.5V AAA Battery (NOT Included)
  • Probe Length: Approx. 18cm / 7.09in
  • Size: Approx. 14.5 7.5 2.5cm / 5.71 2.95 0.98in (L W H)
  • Net Weight: Approx. 110g / 3.88 oz

Package List

  • 1 * Digital Food Thermometer (Batteries not included)
  • 1 * Stainless Probe
  • 1 * User Manual


Failure and Fix

It stopped working this Christmas. After opening it up, it was immediately apparent that the battery connection with had corroded through. Replacing this was all that was required to get the unit working again. Good save - this unit was moments away from going in the bin!

No sign of life:


Pulling the circuit board makes it clear we have an issue with broken battery connector:

build01b build01c

With battery connection repaired, the unit is back in action:


Credits and References

Project Source on GitHub Project Gallery Return to the LEAP Catalog

This page is a web-friendly rendering of my project notes shared in the LEAP GitHub repository.

LEAP is just my personal collection of projects. Two main themes have emerged in recent years, sometimes combined:

  • electronics - usually involving an Arduino or other microprocessor in one way or another. Some are full-blown projects, while many are trivial breadboard experiments, intended to learn and explore something interesting
  • scale modelling - I caught the bug after deciding to build a Harrier during covid to demonstrate an electronic jet engine simulation. Let the fun begin..
To be honest, I haven't quite figured out if these two interests belong in the same GitHub repo or not. But for now - they are all here!

Projects are often inspired by things found wild on the net, or ideas from the many great electronics and scale modelling podcasts and YouTube channels. Feel free to borrow liberally, and if you spot any issues do let me know (or send a PR!). See the individual projects for credits where due.