Someone was asking about a twin display meter and I mentioned the EX540 having an RF link.
https://www.eevblog.com/forum/testgear/twin-remote-display-multimeter/I thought, I should try that out and make sure it really works with Windows 10. I plug in the adapter for the first time and the PC did nothing. I found drivers for Windows 10, installed them. Tried the adapter again, nothing.
Look at the adapter "brand new" purchased from a major distributor and I notice two of the three screws holding the adapter together are missing! I take the third one out and pop the cover. Thread marks where the screws had been inserted at one time. Would be fun to know the history of this meter.
Looking at the adapter, first someone had really mangled where the wires attached to the PCB. Someone had twisted things enough to fray much of the wiring. I cleaned all this up and applied new hot glue. Looking on the top side, noticed one joint for one of the ICs had not wicked to the lead. Cleaned up some of the soldering and tried it out.
The PC now finds the adapter. Run their software, turn on the meter and enable the link. Nothing.....
Decide I better just start with my old meter and adapter that I know works. Sure enough, everything still works. I then turn on my new meter with the old adapter. Nothing. Old meter with new adapter, works.
EX540 comes back apart....
Remember how the new meter was missing the shield on the back cover and I cut a new on out of some foil? Well there were some leads on the RF board that made contact with the foil because they had not trimmed them. Is this why they did not install the shield? Trim the leads, double check the soldering and tried it out. Both meters now work with both adapters.
Was the meter sold, the RF did not work and an unskilled person attempted to repair it? Was it just returned and the distributor attempted to repair it? CEM knowing shipped it defective with missing screws?
Crazy how different these two meters have been...