HP Integral : running ! Not...

[Tony Duell]

>    There's some but I don't think it checks much other than making sure the
> head is at the home position. When you turn the IPC on it runs the head the
> right and then homes it. I think it only checks to see that it's at the
> home postion when it finishs. I don't think it even checks for a non-home
> position when it moves to the right. As far as checking for print head

I am pretty sure it does. It moves the head to the right until it gets a 
non-home position (and then a bit more), then restores to the home 
postion. If the home sensor is playing up, the head will bang into the 
side of the printer chassis (my first Thinkjet had a defective comparator 
chip in the home sensor circuit, and did just that before I fixed it).

> cable problems it does NOT check for anything. (Same for all the ThinkJets)
> The obvious symptom is one or more missing rows of print but that can also
> be due to a clogged print nozzle so you have to use a known good cartridge.

The easiest test (assuming you can find the common connection on the 
cable, which IIRC is pretty obvious) is to check the resistance between 
the common connection and each of the others in turn with the cable 
disconnected from the logic board and a cartridge fitted. It's very 
unusual for the print cartridge elements to fail, so if you get an 
'open' at the logic board end, it's likely to be the cable, alas. Of 
course you can test the cartridge by checking for continuity between the 
contacts on the catridge face.

> they're almost certainly still good.  The other good news is the the
> printer mechanism was designed by Canon (and perhaps built by them) and it
> uses the same cartridges as the Canon Diconix printers so that gives you a
> second source of cartridges.


I thought that the Diconsix printers were Kodak, not Canon. The Thinkjet 
electroncis (which is different to the DIconix electronics) is very much 
HP -- the processor chip has a HOIL port built-in, it uses the Saturn bus 
to talk to the RAM and font ROM (although I am sure the CPU is not a 
Saturn), and so on. 

I was under the impression, probably from HP journal, that the cartrige 
was very much an HP invention. But maybe not.

>   One more thing about floppy drives. HP made single sided, double sided
> and quad density drives. The one in the IPC is DS. The one is the 9121 is
> SS. I THINK the ones in the 913x and 915x are also SS so you can't use them

The 9133H is certainly a DS drive (I use them). The 9153 uses a rather 
different drive. It's still 600rpm, it's still a DS DD drive, it's still 
Sony, but it's the later design with a 34 pin power/data cable and many 
parts also used in the Mac 800K drive (!). It's the same drive unit in 
the 9114B. 

It would be _possible_, I think, to get that later drive in place of the 
older one. But you'd have mechanical problems (at least in the Integral, 
where the drive had no faceplate, the eject button slots into the front 
of the machine itself), you'd have to make up a special cable. The older 
drives are not that rare, it's probably worth finding one.

Remember you can use one with a defective logic board or spindle motor. 
All you need is the head assembly. THere are 2 logic boards used (IIRC 
FC9 and FC16), they're basically interchangealbe, but you might want to 
keep the one that was in the IPC originally. 

-tony