Just some info on a quick repair I just completed.
I bought a JBC JT7750 hot air rework station cheap which was working, although the LCD was just displaying gibberish characters.
Doing a bit of testing showed that the PIC was sending the correct initialisation steps to the LCD (for 4 bit mode) so I suspected the LCDs built in controller itself.
Controller for the station is a PIC18F6621
With a bit of google, the following part from RS appeared to be a good fit:
http://uk.rs-online.com/web/p/lcd-monochrome-displays/5326559/RS number 532-6559
Soldered in the replacement and all up and working! too easy.
I suspect the other JBC products from the same range also use the same LCD.
(White border LCD is original, black is the replacement)