Note that RPM3 has been discontinued and replaced by RPM4
View the below attached document named "power supply kit 3071562, RPM3 replacement, no longer available.pdf" and determine if your RPM3 or molbox RFM has an Ault or Artesyn power supply.
If the RPM3 or molbox RFM has an Ault power supply, the RPM3 or moblox RFM is more than 15 years old and has never had the power supply replaced. The required parts to upgrade to the current power supply are no longer available, so the power supply cannot be replaced. Replacement is the only option. Contact your Fluke Calibration sales representative. The upgrade kit from Ault power supply was part number 3071562, with description (402117) REPLACEMENT POWER SUPPLY KIT, REPAIR RPM3.
The current model power supply (to replace an Artesyn power supply) is this:
Part Number: 5074271
Description: POWER SUPPLY,SW,45W,90-264VAC,5V@5A,12V@2.5A,-12V@0.5A,102X51X28MM,CHASSIS MOUNT
Notes: If you are replacing an Artesyn power supply in a molbox RFM serial number 488 and lower, the below cable is also needed.
This cable is needed for all RPM3 power supply replacements.
Part Number: 5074259
Description: RPM3,ASSY, CABLE, AC/DC, RFM
See this document regarding power supply replacement. It refers to the power supply replacement kit that is no longer available,
Replacement Power Supply Kit for RPM3
Here are other spare parts that are available
3137702 (102714) FEET,SET,TILT-UP
3136290 (102337) FAN,TUBEAXIAL,4.6 CFM,5V,80MA,28 DBA,5500 RPM,SQUARE,40X40X10MM,BULK
3125537 (401450) ASSY, ENCL W/FAN, RPM3
3135423 (102066) VFD,DISPLAY,40 CHAR ALPHA-NUM
3146770 (122809) OVERLAY, FRNT PNL, RPM3 (keypad) - no longer available
3146781 (122812) PNL, FRNT, RPM3 (Metal panel under overlay keypad)