Description: Does your TRS-80 Model III no longer turn on or only partially work? I.e. completely dead or no power floppy drive or serial board? The common culprit is a blown R25 Fusible Resistor on your power supply. Alot of TRS-80 model III computers with a floppy drive will have two Astec power supplies. One for the main computer board and CRT monitor and the second for the floppy drive(s). I am selling two of these OEM Fusible Resistors so you can repair your Astec Power supply. If your Power supply looks like the one in my photo, then these fusible resistors will work on it. I am including some screen shots of the Sams TRS-80 model III service manual which indicates power issues are usually attributed to the R25 fusible resistor burning out (going open). Your R25 Fusible resistor may look different than the ones I am selling as show in a photo where I display two different failed ones from astec power supplies. You can easily test your R25 Fusible resistor with a multimeter set to Continuity check. If you get continuity across the two pins it still works, If you get nothing it has failed and needs to be replaced. I found this is a very common failure on model III power supplies. Listing is for two Fusible Resistors, no PSU is included: only shown for installation and compatibility. Please contact me with any questions I am happy to help. NOTE: Your PSU may have other problems such as a failing or failed supression capacitor (incorrectly called a RIFA capacitor). Or failing electrolytic capacitors. These Fusible resistors are a first obvious item to check prior to further troubleshooting. DONT BUY ANOTHER 43 year old Power supply when all you need is a new Fusible Resistor!
Price: 11.99 USD
Location: New Milford, Connecticut
End Time: 2024-08-03T17:46:03.000Z
Shipping Cost: 0 USD
Product Images
Item Specifics
All returns accepted: ReturnsNotAccepted
MPN: Psu repair parts
Vintage: Yes
Country/Region of Manufacture: United States
Model: TRS-80
Brand: RadioShack
Type: Home Computer
