Tefal induction cooktop working but not heating ;-)

[pagaille]

Hi,

Any pointer to help me repair my portable induction cooktop ? (TEFAL IR-2018)

Symptoms : suddenly cease to heat. No error message. When changing program / power level, the display flips between the previous program and the animation showing that the plate is supposed to heat.

So far I tested the usual suspects :

- Power supply
- IGBT --> not shorted (no functional test done though)
- Diode bridge
- Safety Relay
- Capacitors
- Some low power components around the IGBT driving stage.
- Thermistors (3 on the plate, one under the IGBT) looks ok.

Everything is ok. The device looks ok and is well engineered (european standards).

When powering on there is +320V. If I start to cook the voltage at the coil falls to zero (to be confirmed, I should measure again) and nothing else happens.

Without schematic it's hard for me to get other ideas . Any advice ?

Thanks :-)

Matthieu

[abraxa]

If there's no error message then either it lacks circuitry to measure something essential or something is broken that can't be measured. I'd be surprised if they measure the voltate across and the current flowing through the coil, so from my limited experience with power electronics, I'd guess that either the IGBT isn't conducting as well (anymore) as it should or the connection to the coil is broken. What's the resistance of the coil anyway? Maybe one of the connectors suffered from stress? Maybe one of the coil connections broke from vibration of the coil itself?