Even though I don't understand his language, he has demonstrated how to fix the built in flash pop up problem. I even add a drop of light machine oil to lubricate the part. It works on my old 40D and the problem never return.
I quoted hereunder from : "http://www.justanswer.com/digital-cameras/6jkxj-flash-unit-canon-eos-rebel-t3-will-not-raise.html
" which explain the problem.
The spring latch on the pop-up flash can stick. It is part of the hinge in the rear. You can try to gently raise the flash and while I would not suggest that you force it open, try to get a fingernail or stiff business card under it while it is clicking and gently help it up. If you are able to get the flash to pop up, you need to clean and lubricate the latch and spring with something like WD40, since dirt and grit can block the correct operation. If you are unable to get the flash to open, the unit will need to go to Canon for service.