Pro Graf 1000 cartridge pops out

[Zen-in]

I bought a used Canon Pro Graf 1000 a couple of months ago, and have used it lightly.  Today I tried printing and got an error message that the printer was offline.   Since 4 cartridges were almost empty I decided to replace them.  After I removed the first one, MBK, the replacement cartridge would not stay in.  I can push it in and see it recognized on thr LCD screen, but as soon as I stop pushing on it, it pops out and is missing on the display.   The other 3 cartridges all went in ok.  I have read some suggestions about unplugging the printer, power cycling, etc.  None of those Dumbo AI suggestions work.   Has anyone had this problem?   How did you resolve it?   Should I junk my nice printer now?

[Zen-in]

I was able to do a work around and print ok.  I used double sticky tape to attach 6 1.25" X 1.25" pieces of cardboard together.  I stuffed that against the MBK cartridge and closed the ink cartridges door.   Using 2 small C-clamps and a piece of Al right angle, I clamped the Al right angle to the table and against the cart door in front of the MBK cartridge.    This keeps the cart door from flying open.   Printing went ok.   I didn't see any "debris", "plastic" or damage inside the  MBK slot.   Anyone have this problem?

[SignifDigits]

I'm glad to hear that you figured out a workaround.  I would suggest that you call Canon for diagnosing this problem.  I'm not personally familiar with that problem.  Worst case it sounds like you might have a damaged retaining latch..  Best case there is some ink or something back there (actually that might be a huge pain to get to so maybe not a great best case) blocking linkage or you're using a third party cartridge that isn't 100% mechanically compatible.  I'm assuming these are Canon cartridges and not third party?

The PRO-1000 carriage apparently utilizes a small plastic mechanism that clicks the cartridge in.  This part of the AI answer below sounds about right to me (you'll have to register the printer registered to get support):

• If you insert the cartridge and it continuously pops back out, the spring mechanism or the retaining teeth on the carriage may be broken. 
• Do not force it too aggressively, as this can snap the plastic tabs. If the slot mechanism is broken, you may need to arrange a repair through the Canon Support Center.

[Zen-in]

The same thing happens with the old cartridge, so the issue is not with the cartridges I bought.   I may have done something wrong when I did the replacement.   In the manual it says to go to y he replace cartridge menu, click OK, and open the cartridge door.   I didn't do that.   I opened the cartridge door and removed the MBK cartridge first.  That's the one that pops out.   Except for it not staying in, everything works OK.   The cartridges I replaced display as being full and the printing I did was ok.