I have HP LASERJET 500 M525 printer, but when I start it, after one minute it shows 49.38.03 device error, then the printer restarts. What should I do?
There is a solution for this problem. You will need to access the HP pages in order to see the discussion about the 49 error.
HP Support page: http://h30434.www3.hp.com/t5/Printing-Issues-Troubleshooting/LJ-Pro300-color-MFP-M375nw-Power-cycling-displays-quot-49/m-p/5077149
Additionally, this could be a firmware error. If the printer is in the warranty period, then you need to send it back for memory reflashing or replacing.