Time before display dims (Tdim)

[Joe Horn]

DrDJones, I might have a solution for you. At least it works on every Prime I've tried, including two HW rev A machines (PCB rev 00 and 02) and two HW rev C machines (PCB rev 01 and 03). Just backup your contents using the Connectivity Kit, then perform a C+F+O+On "Format Disk C" master reset of your memory to factory condition. After that, the display will dim properly, according to the value you store in TDim.

[For the uninitiated, here's how to perform that master reset if you have a HW rev A or C machine.* Turn it off. Press and hold down the C, F, and O keys (that's the letter O, not the digit 0). While holding them down, press and release the On key. While still holding them down, wait a few seconds until you see the EA656 DIAGNOSTIC screen appear, then release the C, F, and O keys. Press 4 then 3 then Enter. When you see "OK" in blue next to "Format Disk C", press Esc then 9. Your Prime will perform its "Welcome" setup routine.]

If your Prime reverts to always dimming at 30 seconds after you restore memory from your backup, then your backup is corrupted, in which case you should export your programs one at a time, Format Disk C, then reload the programs one at a time, thus avoiding restoring from a corrupted whole-machine backup. Tedious, but way better than retyping everything from scratch.

Disclaimer: If HW rev A and C machines are not supposed to support TDim, then the above solution might only work for a little while after the "Format Disk C" is performed. I have yet to see it STOP working, though. Therefore, please share any insights you have along these lines. Thanks in advance!

* The only difference in performing the "Format Disk C" for HW rev D machines is that instead of tapping the On key while holding C+F+O down, you poke a paperclip into the Reset hole in the back while holding those keys down. The rest of the procedure is the same as above.