I did finally figure out and fix the problem of the frozen printer head with accompanying alarm light/error message.
In short I had to go deep, strip the machine and thoroughly clean the purge/cleaning unit under the head assembly. That included cleaning the 2 small ceramic filter pads, the 4 tiny vaccuum tubes (the 2 larger ones were plugged) and the large ink blotter pads that lie on the very bottom of the machine.
When the original problem occurred I heard a loud crack and assumed something had broken. Turned out the 'clockwork' mechanism of the purge unit had forced itself apart and was no longer functioning - probably due to the aforementioned vacuum tubes. I disassembled and realigned the 'clockwork' mechanism as well - which took several attempts of course.
It all took the better part of a weekend but the printer works like new again.
For a first-timer I found taking it apart wasn't difficult just time consuming. What worked well was a very fine marker and masking tape. I circled every screw hole as the screws came out and used masking tape to tape the screws in groups to each component as it came off. Anything that looked like it might give me future trouble I reassembled immediately after disassembling as a practice run before taking it off again and setting aside.
For those of you about to embark on this particular MP 730 journey it is a top - down disassembly. The major component removal went like this:
1. back 2. motherboard cover (right side under the scanner) 3. scanner top - remove the pin in the center of the support arm 4. pull motherboard and underplate 5. remove mid-body section 6. remove paper roller assembly - everything was accessible at this stage except for 2 small vacuum tubes which turned out to be clean anyway, and the misaligned clockwork mechanism. I had to pull the the purge/cleaning unit from the roller assembly to fix the 'clockwork' mechanism.
As they say all's well that ends well and Good Luck!!
