Model #7800 Fast Charge Cordless Soldering Iron Troubleshooting

Although now obsolete, many of our older irons are still in use today. The tips used in our current irons are compatible with all battery powered soldering iron models. While we no longer service the obsolete irons, replacement parts are still available through other sources and many are able to be maintained and repaired to this day. We strongly recommend only repairing your iron at home if you are familiar with using a soldering iron.

Fast Charge Cordless Soldering Iron Battery Assembly

As the owner of the Model 7800 Fast Charge Cordless Soldering Iron, you may have noticed a snap disc thermostat assembly on the battery pack. When the user presses the white lever, they are sending the soldering iron into the fast charge mode, causing the battery to heat. The snap disc then senses the temperature changes and “snaps” at 125°F ±8°F. Once cooled down to 105°F the snap disc automatically resets, returning the battery to normal state. Also note, if the red LED light never comes on, it’s likely the snap disc plunger is stuck.

Another potential thing you’ll notice if the snap disc on your unit has failed is that the iron, near the battery pack, is hot. So, what is hot? Well, being the snap disc isn’t triggered until 125°F, if you place a temperature probe on the outside of the soldering iron, you’re more than likely to find it to read out 105°F. But if you are seeing above 135°F, then you may have a problem with the thermostat.

If this part has failed, you’re in luck! We make snap disc thermostats too! Check them out here. It’s that odd mini hockey puck looking thing with the red plunger on the tip end of the battery. The plunger fully extends, meaning the battery is at maximum temperature signaling it’s fully charged. There needs to be a small air gap (.010 roughly) between the end of the plunger and the white arm. The white arm is the slide that activates the fast charge mode on the side of the iron. The air gap needs to be available, otherwise the plunger may not fully extend keeping the soldering iron in fast charge mode. If the air gap is too big the fast charge mode may not become activated and you just paid a bunch more money for our basic Quick Charge Pro soldering iron Model #7700.

Where to Find a Replacement Battery

To find a replacement battery for this model we recommend contacting your local Batteries Plus store as they may have a replacement battery option available. Our battery supplier obsoleted this item on us, so unfortunately, we have to pass on that obsoletion.

Last, but certainly not least, we offer a great upgrade program – 20% off the purchase of one of our current models. You can contact us here about!

Have any questions? Click here to contact us today!

Want more information? Check out this PDF instruction manual!