Thin lines distorting my images in my Digital camera?

When I use an external power source in my Canon Digital Camera the Image taken by flash is full of  thin Gery horizontal lines.
These lines do not come when photo is taken in daylight. Only the Flash Photo is effected. WHY?

My guess is that the external supply is interfering with the camera, by injecting noise into it over the supply cable. Try a different (but correctly rated) supply, or even a battery pack.

yokozuna7 years ago
Yes, as Nacho suggests, pics will help identify the problem. Are the lines horizontal or vertical? Vertical Lines would suggest a lighting problem, horizontal lines would suggest a hardware problem, possibly something like steve is suggesting.
rimar20007 years ago
I agree with steveastrouk, Dipankar, 99.8% sure.
NachoMahma7 years ago
. Can you post a sample pic?