Is this a pic of a fusable resistor?

This component burned the pc board in a curling iron but has no color coding and currently reads 33Kohms. Any ideas?

Welcome to the Digikey tech forum. Can you provide photos of the PC board to see how this was used and maybe there’s a marking on the board that can give information on the part ID. Does the curling iron not work at all or just not as good as it should ?


Sure, here’s the board pic. Burned area is labeled R1 and the component is connected to the white heating element wire on one end and the capacitor on the other. There is 120 power to the board and the LED lights but there is no heat generated. I believe the heating element itself is OK as I measure 82 ohms between the two white, thermally insulated wires.

Unfortunately we would not know what the resistance on the heating element is.

If you need a replacement resistor we would need to know what wattage, tolerance. That would narrow the options down a bit. The link below shows the 33K ohm resistors we have in stock.

Hello bar,

Welcome to the DigiKey Tech forum.

Unfortunately, consumer electronics can be difficult to repair. For example, consider the large S2D6BN component on the circuit board. Based on the circuit design I am led to believe this is a thyristor, most likely a triac, used to control power to the iron’s heating element. Unfortunately, I am unable to locate a suitable substitution.

This is not unusual as manufactures often order large quantity of custom semiconductor components for a low cost. The custom / proprietary component marking makes it difficult to locate suitable replacement parts. This is good as it keeps the cost low but can be bad as it makes repair difficult.

As for your iron, I suspect the resistor is a symptom of a greater defect. I would recommend replacement of the capacitor, small semiconductor (assumed to be a diac) and the larger semiconductor component (assumed to be a triac). Unfortunately, that is a difficult proposition as mentioned above.

Until then:

  • Perhaps another reader will be able to locate a replacement part.
  • You may also be able to locate a teardown video for the iron.
  • You may have the skill to reverse engineer the circuit and intuit replacement parts. Unfortunately, this is not easily done unless you locate a working circuit and a good deal of experience.
  • There is a small chance that a user group exists for the iron. Such a group would share repair tips.
  • There is a small chance the iron could be repaired. However, I suspect the return on investment will be low as the cost of skilled labor to affect the repair is often higher than replacement cost.

I sympathize with your environmental concerns and attempt to repair the device.

Best Wishes,


Thanks for the feed back. I agree that the cost-benefit of repairing this is probably not worth it but your comments help. As you noted it probably is the triac or diac. I was mostly just curious if it might have been something easy like a fuse but it’s always interesting to see how these common appliances implement the technology.

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Yes, I should have mentioned the education component.

On the one hand, I must focus on caution so that our readers don’t electrocute themselves, someone they love or burn down the house. On the other hand, you correctly point out the knowledge to be gained by examining and repairing equipment. The caveat is to do so under the guidance of a mentor.

As for a fuse, unlikely.

If it was a fuse, something else is wrong, hence my shift of focus to the semiconductors and the capacitor.

Keep exploring!