40D Red dots not working

My 4 year old 40D has a frying sound when I hit the little AF button or mash the shutter button haft way down. The little red dots for focusing does not light up either way.

Can anyone tell me what the problem is ? Just started latley.

Is the frying sound coming from the lens? If the lens can't auto focus, the red focus points will not light up. Maybe remove the lens, clean the contacts on the camera and lens with a soft cloth. Do you have another lens to try on your camera?
...Terry

The nearest explanation I can think of is that the noise is the lens IS operating (possibly it has become faulty and the noise more noticeable or different in character), and that you have the camera in AF servo mode, so the focus points will not illuminate.

Overkill, I put my 100-400 on and took it outside. No frying sound and the red dots lite up. It seem that when my kit 28-135 is on and inside and the flash pops up is when the frying and no red dots happens. Going to take the 28-135 outside and see what happens.

Had the 28-135 outside and no frying and the red dots lite up. Guess the 28-135 could not focus inside because of not enough light, Huh? Need a Bigger Flash.

You won't get the AF confirm red squares if you are in AI Servo - set that back to One Shot