FAQ
TL;DR: TM5’s jumpy knob points to a dirty encoder; "Disassemble 2 plugs and continue working with the 'encoder'." Two latches under the knob give access; clean contacts to restore smooth steps. [Elektroda, Dariusz23a, post #18976436]
Why it matters: This helps TM5 owners and DIY repairers quickly fix erratic time/temperature/RPM selection without costly service.
Quick Facts
- Main dial uses an unusual rotary encoder, not a potentiometer. [Elektroda, asura.kk, post #18634839]
- Do not use WD‑40; use electronics contact cleaner (e.g., Kontakt PR). [Elektroda, asura.kk, post #18634839]
- Under the knob, a white ring with 2 latches exposes the encoder; it has 2 plugs. [Elektroda, Dariusz23a, post #18976436]
- Strain‑gauge connectors are interchangeable; tare recalibrates the scale each time. [Elektroda, mipix, post #21249752]
- Full TM5 teardown with part locations is available on iFixit. [Thermomix TM5 Teardown]
Why does my Thermomix TM5 knob jump values when I turn it?
The dial uses a mechanical encoder whose contacts need cleaning. A member notes it is an unusual encoder, not a potentiometer. Clean the encoder with proper electronics contact cleaner. Avoid WD‑40 on the electronics. This typically restores smooth, predictable steps. [Elektroda, asura.kk, post #18634839]
Is the TM5 dial a potentiometer or an encoder?
It is an encoder, not a potentiometer. That matters for troubleshooting and chemicals. "The dial is quite an unusual encoder." Use contact cleaner rather than lubricant on the contacts. [Elektroda, asura.kk, post #18634839]
How do I access and clean the TM5 encoder?
Follow this 3‑step process:
- Lift off the knob gently. Unlock the white ring’s two latches and slide it left.
- Note the short wires. Disconnect the two encoder plugs before handling the module.
- Clean contacts with electronics contact cleaner. Reconnect, re‑seat the ring, and test. [Elektroda, Dariusz23a, post #18976436]
Should I use WD‑40 on the encoder?
No. "Absolutely NOT WD40 !!" Use a cleaner formulated for electronic contacts instead. WD‑40 is not intended for precision encoder contacts. A contact product like Kontakt PR is recommended by repairers. [Elektroda, asura.kk, post #18634839]
Which cleaner should I use to stop the jumpy values?
Use an electronics contact cleaner. One repairer recommends a thermoplastic preparation for contacts, such as Kontakt PR. Apply sparingly to the encoder, rotate the shaft, and allow it to evaporate. Reassemble and test for stable increments. [Elektroda, asura.kk, post #18634839]
Do I need to fully strip the TM5 to reach the knob encoder?
No. Remove the front cover, then the knob and white ring to access the encoder. Watch the short encoder wires. Disconnect its two plugs before cleaning or reseating the module. [Elektroda, Dariusz23a, post #18976436]
How do I remove the TM5 knob without breaking anything?
Lift the knob gently. Under it, unlock the white ring’s two latches and slide the ring left. This exposes the encoder and its plugs while reducing strain on the short wires. [Elektroda, Dariusz23a, post #18976436]
Is WD‑40 safe for TM5 electronics?
Avoid it. As one contributor put it, "WD40 I advise against electronics." Use a dedicated electronics contact cleaner to avoid residue on signal paths. [Elektroda, ducker1, post #18516253]
How many connectors go to CN350, CN360, and CN370?
Three identical 5‑pin connectors plug into the mainboard at CN350, CN360, and CN370. They look the same and may not be labeled on some units. [Elektroda, nickwilson2166, post #21246849]
Does connector order matter for CN350/CN360/CN370 after reassembly?
No. These are strain‑gauge plugs from the feet. You can connect them in any order. The scale calibrates each time you press tare. [Elektroda, mipix, post #21249752]
Do I need to calibrate the scale after reconnecting those cables?
Manual calibration is not required. The device tars and calibrates the scale on each tare action. This design allows interchangeable strain‑gauge connections. [Elektroda, mipix, post #21249752]
What symptoms point to an encoder issue on the TM5?
Values jump up or down unpredictably despite gentle turns. For example, time can jump from 00:10 to 00:45, then to 01:24. The behavior lacks regularity and also affects temperature and RPM. [Elektroda, broo, post #17137089]
Where can I find a dependable disassembly reference?
Use the iFixit Thermomix TM5 Teardown. It provides a step‑by‑step guide with photos and part locations. Follow the sequence to avoid damage. [Thermomix TM5 Teardown]
Any precautions to avoid damage while working on the encoder?
Mind the short encoder wires when removing the front cover and knob. Do not pull on the harness. Disconnect the two plugs before manipulating the encoder assembly. [Elektroda, Dariusz23a, post #18976436]
