Fender M80 "TH1" Thermistor

[Will M]

I got an old 1990 Fender M80 amp head from a guy on Craigslist last winter. It worked great for about a month then one night it started cutting out and then completely went dead. I opened it up and saw that one of the components marked TH1 had burned pretty much right off the board. After a little research it turns out it is a thermistor. Tracked down a schematic of the board on which it is also identified as TH1. It is located in the top-right corner of the board - C1 section of Fender drawing number 037027.

I called Fender's customer service line and the guy was very helpful in looking it up but wasn't able to find any info other than the part number - 026411.

After googling it some more I came upon your forum with some great detailed answers about components etc. Just wondering if anybody has any more info on where I could get a replacement, or more specifics about the component itself so I could find something that would work in it's place.

Thanks in advance, Will

[Jazz P Bass]

2.5 ohm/ 5 amp are the specs.

https://www.manualslib.com/manual/74...20.html?page=6

[The Dude]

We could help you find one, but we don't know where you live. You may want to add your location to your profile. Welcome to the place.

[mozz]

I've got a M80 chorus chassis for parts, it has the TH1 next to the fuse holder, send me a PM if interested.

[g1]

Also: Fender Thermistor 2.5 ohm 8A C19 0026411002

[Will M]

Wow! You guys Rock!! Thank you all!

So the 2.5 ohm 8A thermistor that g1 posted would offer the same resistance but let more current through. Do you think that would work ok in place of the 5A original one?

[mozz]

Numbers on factory part. KCC C30-19. It's not going to let any more current through than any other part, the current rating is the handling ability. Have you troubleshooted the problem? If you replace the part it may well burn up again, you have to figure out why the part went bad in the first place. I haven't seen the schematic so i take it this part is on the transformer primary?

[g1]

All the references I've seen show it as 8A rating, there may be a typo in the link Jazz provided. Higher current part would be as good or better anyway. And that is the current version of the Fender part # you provided.
There were a run of these thermistors that had too much of a kink put in the leads during production. The lead would then crack and start arcing. Or the solder joints would crack and lead to arcing.
Otherwise, find out why it failed as Mozz suggested, although the fuse should blow first if the current is too high.

Edit: that typo was by Jazz , his link shows 2.5 ohm/8 amp.