Recently my hairdryer stopped working properly. While drying my hair, the fan would suddenly turn off after a minute or two (it seems as if a thermal switch in series with the motor cut the current to it). It looked as if the heating coils were still powered, they heated up quickly with no more airflow and started to glow red, before also being cut by there own thermal switch. After that it would take about half an hour before I could use the hairdryer again. However, the behavior was the same again, with the fan turning off after short use.

I disassembled the hairdryer and found that it contained the motor shown below. It turns out that this is a fairly common motor for haidryers, a U5215 universal commutator motor. When disassembling the hairdryer, the motor was still warm (about half an hour after I was using it and it shut down). It tried to remove any dust that had accumulated (assuming that it was causing additional friction or blocking cool air), but unfortunately that did not help and the motor is still overheating after a minute of use.

Is there anything I can do to make this motor work properly again? Should I replace the motor (motors of this type seem to be available online)? Or should I simply buy a new hairdryer?




closed as off-topic by Chris Stratton, Charles Cowie, Phil G, Oleg Mazurov, evildemonic Sep 5 at 14:59

This question appears to be off-topic. The users who voted to close gave this specific reason:

  • "Questions on the repair of consumer electronics, appliances, or other devices must involve specific troubleshooting steps and demonstrate a good understanding of the underlying design of the device being repaired. See also: Is asking on how to fix a faulty circuit on topic?" – Chris Stratton, Charles Cowie, Phil G, Oleg Mazurov, evildemonic
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  • 1
    \$\begingroup\$ I don't think the thermal switch disconnects the motor leaving heating coils to work further, if this is the case then it's very stupid engineering. \$\endgroup\$ – Marko Buršič Sep 3 at 8:45
  • \$\begingroup\$ @MarkoBuršič I looks as if it does, since the coils get red hot after the fan has stopped and only turn off a few seconds later. \$\endgroup\$ – kassiopeia Sep 3 at 9:22
  • \$\begingroup\$ It could be a faulty thermal switch on the motor, causing it to turn off prematurely. \$\endgroup\$ – HandyHowie Sep 3 at 11:04
  • \$\begingroup\$ The replace the motor or replace the product decision is a matter of economic evaluation. It may be possible to replace the thermal switch, but there is likely no easy way to determine if that is the problem other than replacing it and evaluating the result. Since there seems to be no opportunity to solve a problem by engineering analysis, I am voting to close the question. \$\endgroup\$ – Charles Cowie Sep 3 at 13:42
  • \$\begingroup\$ If the thermal switch is causing the motor to stop (and I'm not sure about that, these small motors usually have a one-shot thermal fuse) there is likely a cause for that - either a winding short, an open connection at the commutator, or mechanical drag causing the current to be excessive. Probably not worth throwing more effort and money at it. \$\endgroup\$ – Phil G Sep 3 at 14:40

A motor like that has brushes; carbon piles that make contact with the rotor. they are likely worn out / dirty. You can see the holders for them, they are the squarish brass tubes on opposing sides. In addition it looks as though your commutator, that part that the brushes make contact with, may be dirty and/or worn out as well. Most cheap little appliance motors like this do not make the brushes replaceable and 'servicing" the commutator is less than practical.

It has "shuffled off its mortal coil"...


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