Yeah, these printers are dirt cheap compared to parts...
http://www.fixyourownprinter.com/troubleshooting.html
Error 50 (fuser malfunction)
a.. HP II/III series most likely cause is the ac power module is defective.
Order the HP II/III Service 50 Error Repair Kit Quartz fuser lamp is burned
out. Order the replacement fuser on specials page. Slight possibility of
loose connector on DC controller. See tweaking page DC controller could also
be defective, but this is very rare.
a.. HP IIP/IIP+/IIIP most likely cause is burned out quartz lamp. Order the
HP IIP/IIIP 50 Service Error Repair Kit. Could also be a failure of the
power supply.
a.. HP 4/4+/5 most likely cause is burned out quartz lamp. Order the HP 4
Service 50 Error Repair Kit. Could also be a failure of the power supply.
a.. 4L/4P/5L/5P/6L/6P most likely cause is a bad ceramic heating element.
a.. All other printers most likely cause is burned out quartz lamp. In rare
instances the ac power supply has failed. Even rarer, the DC controller is
defective.