k8gu.com : repair notes

Salton Rice Cooker
Diagnosis

The Salton RA3AST 3-cup automatic rice cooker is an indespensible appliance for lovers of rice and oriental food. An old roommate had a rice cooker and I immediately became a fan of its moist, perfectly-done rice. As a wedding gift, we received [from the roommate] a rice cooker of our own.

However, after the first batch of rice, the device refused to turn on. I contacted my friend about whether he still had a receipt for warranty service. He did not. Out-of-warranty repair would involve sending the cooker to the repair center with return postage in addition to the repair cost. This would have approached the cost of a new unit. Furthermore, since without the receipt, the warranty was effectively void anyway, I elected to attempt the repair myself.

I removed the two sheet metal screws holding the bottom cover and had a look around:

I traced the wires from the plug inward using an ohmeter. I noticed that one of the wires was continuous [about zero resistance] and that the other one was open [infinite resistance]. I removed the screw holding the open [upper of the two wires in the photo above] conductor and pulled the white insulation off. Beneath the insulation, I discovered a component I assumed to be a fuse.

It turns out that the fuse is actually a thermal fuse, designed to prevent the cooker from overheating and bursting into flames. This was important because it gave me hope that there wasn't anything deeper wrong with the cooker. The marking on the thermal fuse is SEFUSE SF139E 142C 10A JEC 250V C0385. Believe the part is manufactured by NEC. However, I was unable to find a supplier for the part. Having discovered the wonder of NTE replacement parts previously, I searched for an NTE replacement. Viola! NTE manufactures a whole series of thermal fuses. Conservatively, I selected the 141 degrees celsius NTE replacement for this 142 degrees celsius component.

Repair

Fortunately, the replacement of the thermal fuse is within the reach of anyone with some basic do-it-yourself skills and tools. The NTE8139 thermal fuse is available from most suppliers who stock NTE replacement parts. Since I just moved from Minneapolis to the sticks of Urbana, IL, I had to order mine from Mouser Electronics. Another good supplier for NTE parts is Jameco. I understand that you may also be able to obtain thermal fuses from local appliance repair shops, if you have one. Update: some of the better RadioShack stores also carry several values of thermal fuses. Once you have the part in-hand, you will need a philips screw driver, a pair of needle-nose pliers [I used Vice Grips], and a side cutter.

Here's the proceedure:

Remove the two screws holding the bottom cover and set the cover aside.
Remove the screw holding the shorter of the two power line wires.
Slide the white insulation off the thermal fuse.
Noting the orientation of the black end of the thermal fuse, pry it loose from the crimp connectors. [Note: you may find it easier to simply clip the leads on the fuse and use the NTE-supplied crimp connectors to attach your new fuse to the existing wires.]
Install the new thermal fuse.
Slide the white insulation back over the fuse.
Re-attach the wire lug to the post with the machine screw.
Put the two sheetmetal screws back into the bottom cover.
Enjoy some rice again.

That's all there is to it. Conceivably, you could solder the fuse. But, that a bad idea since lead and food are bad. Furthermore, if you're not skilled with the solder iron and don't properly heatsink the fuse, you'll destroy it with the heat.