Jammed cradle on HP 840C printer

[MalcolmY]

Yes, OK, I know it's ancient (10 years old) but it was going fine untill this morning when suddenly when I tried to print a document both the Power and the Printer Ready lights started flashing. This is normally an indication of a paper jam but having removed the rear door I can confirm there is no jam. I have tried turning the printer off and back on again - to no avail. I have uninstalled and reinstalled it and still the lights are flashing. I have tried the printer on an old (Win98) computer which it was bought for originally and the same thing happened. The only difference was that this old set up seemed a tad more user friendly than my later set up in that I got an error message saying that the Printer Cartridge Cradle can't move (or words to that effect). Again it suggested a paper jam - which there ain't!
Has anyone got any ideas as to how I might get my cradle moving again. As you will see from the above comments I think I have tried all the HP suggested remedies - and a few of my own. I would very much like to get my favourite (until today!) printer working again.
Thanks

[AlBags]

I should think the mechanism has a broken gear .. or a tooth off it.
You will have to strip it to find out!
That may be the end for the old girl ...
My 'second' printer is an HP895Cxi .. probably as old, but great printer .. and quiet .. unlike the high pitched whining from newer ones.

[MalcolmY]

Thanks for your comments, AlBags. I am having a bit of difficulty stripping it down. I've got a rare selection of security bits which allow me to get into most appliances (irons , toasters, cd players, etc - in fact most things that Mrs Y thrusts at me with a soulful look) but I can only manage to undo a couple of screws. This did enable me to move the cradle and remove the cartridges. I don't know about a broken gear (or spring?) but underneath where the cradle sleeps there was a 10 year accumulation of what in polite circles can only be desribed as gunge. You can guess what the more impolite word could be. I have concluded, rightly or wrongly, that it is this gunge that is preventing the cradle from moving freely. As there doesn't seem to be any way to get at this particular area of the printer, I am reluctantly going to bid farewell to the loyal old thing and see if I can get to love my cheapo, noisy HP F4180 AIO.
Thanks again for your comments.

[Wak]

Just out of interest, I had an HP F380 printer, 3 years old but very regularly worked, which just stopped for no apparent reason and started the lights flashing.
Nothing I did could restart it and I eventually assumed that the flexible lead which allows the side to side movement of the cartridge carrier had eventually created a bad or broken connection.
I now have an F4580 and know what you mean!!!!!