I have tried deep cleaning several times on my Pixma iP5000 but can still not get the blue and magenta colours. Thr printer has been stand still for approx 4 years. Black and yellow works fine.

If you have clean the print head several times,the problem is the prin head,you need to replace.

One of the he cartridges is evidently defective.
Replace all cartridges with original ones.
After replacing, perform a clean head procedure from printer utilities. Do this several times.
That should fix the problem.

If that does not fix the problem, than you have a faulty print head.

Check the Magenta cartridge, is ir empty?
Do a maintenance head cleaning (do a deep clean) - check the Magenta print head, is it still blocked.

Hello,
are your rubber washers still in place? Are you using OEM cartridges or refilled?

When elements on the printhead burn out, that's what it looks like.You need a new printhead, QY6-0057-000, around $50.00

It seems the nozzles of one of the ink chamber are clogged, try deeping the nozzles in warm water for 5-10 minutes to remove the clogg.

Every time I have had problem have had to replace ink.

The other week I had the black print head clog up, requiring daily nozzle deep cleaning [a normal 'ocassional' maintenance function]. Thought I needed a new Print head, so anything worth a try.
I loaded up an old black cartridge [I load all my own......always have] with Isopropyl Alcohol and ran deep clean on that cartridge a couple of times, then repeat printed [6 times] a page full of the number 8 in about half inch character size, to get the alcohol through the nozzles. then Deep cleaned again 3 times, to wash it through the print head.

I reloaded the normal ink filled cartridge and ran the '8' page again till I got good black output. It has now been working without problem, daily, for over a week. Clearly if it's a Magenta only problem, the cleaning as described above would be a bit different, as the magenta is one of 4 colour cartridges.
My printer does quite a lot of work, and was bought at least a couple of years ago, being used daily for alpha numeric and photo printing work. This was the first difficulty I experienced with it.
Hope the above might help.Ken

Think you need to clean the sponge that the ink cartridges sit on in the head tray they are probably blocked with dry ink. You can remove the print head and tray by lifting the lever and gently lifting it out..... go here http://www.inkjethelper.com/
to see how to carefully clean it with compressed air. I had to do this too.

Normal 0 Driver could be corrupt.
Disconnect the printer or at least be sure it is turned off. I'd do both and reinstall the CD software program that came with the printer. When the software program asks you to connect the printer to the USB port, do so and it should again work properly.
Hope this helps. Bud