Wanted to share the following quick and cheap fix I came up with for the broken backlight issue on the Rocket R58 PID controller.

Some time ago I recall hearing a rattling in my PID and I thought nothing of it. Come to realize a few years later that the display backlight is actually completely broken. New ones are ridiculously priced if you can even get them, not to mention throwing good money at such a lacklustre design. So I just left it.

Eventually it got to me enough that I pulled it apart to see if I could see the issue. I discovered that there was a missing resistor of unknown value (R8). With this resistor missing, there was a break in the circuit and the LCD wasn't getting any power to its backlight.

The solder pad was damaged/completely missing so I decided instead to look at just getting a whole new LCD unit. After some hunting around I found an exact match on AliExpress. The newer unit has a smaller ribbon cable but this actually help with installation. Shipped to the US it was only $8.44 and arrived in 14 days.

Installation was as simple as removing the back pate and then the risers holding the PCB in place. You can then gently pull the cable attaching the LCD module to the PCB. Transfer the three nylon standoff spacers to the new display, plug the cable in and snap the LCD in place.

I'd be really interested to know if anyone else has had this issue, and whether or not your R8 resistor was missing. If someone has a functioning PID and could verify the numbers on that resistor it might also be able to be replaced without replacing the whole LCD.

Hope this helps!