|Re: HP2225B problem!|
Message #9 Posted by Tony Duell on 11 Apr 2006, 5:54 a.m.,
in response to message #8 by Ignazio Cara (Italy)
Does the carriage move when you turn the printer on? It should move to the right (clear of the home sensor), then back to the left (at least)?
I have a Thinkjet service manual. From what I remember, it does an internal self-test at power-on, if this fails, it doesn't move the carriage. So the carriage not moving could be due either to a problem with the carriage motor (driver circuit, the motor itself, mechanical stuff) or a problem with the microcontroller circuit. I also seem to remember that if the self-test fails, the microcontroller outputs a pulse on one of the lines used to drive the printhead (the printhead power supply is disabled, it won't print a dot). You can detect this pulse with a logic probe. Which line pulses depends on what is defective (microcontroller, font ROM, RAM, etc).
Assuming the carriage never moves, I would start by making sure the carriage is free. Then ask me (by private e-mail) to get out the manual and I'll tell you what signals to look at.