How can i turn on the flash light in the cam when shooting at night?

Not being able to take pictures _at night_ likely has nothing to do with your SD card. If the SD card works during the day, it should be fine at night, too.
Any camera needs some light to take pictures. Many use flash to take night time pictures, or infra-red (IR) lighting. I don't know your camera well enough to know if you have either or how to configure how to turn that on.

Night mode? As a professional I can set a camera to shoot at night by the settings thats why we dont use point and shoot cameras
go buy a Nikon D90, or D3100 and set the modes for night shooting
good luck.

I have been playing around with UV but have not found one the works. except years ago I found that the cameras that were now available on cell phones was a great way to see if your TV remote was working,
so you can use this feature on your phone to help you find the light thats not visible to the eye but your camera will dig it
ones i tried w my Lumix FZ70 using ebay
#1 is 9pcs Array LED Illuminator IR Infrared Night Vision Light for IP Cameras.
#2 1pcs 4IR LED Infrared Illuminator Light IR Night Vision for CCTV Security Camera
both work well for security cameras but failed with my lumix and the 4ir seem to burn out quickly
I'm a hopeless cheapdate and refuse to spend 2-3 hundred on a light. let me know wht ya find ?
jay YONGNUO YN600EX RT II HSS 1 8000s TTL Master Flash Speedlite Light for...

If these are flash pictures, you are experiencing dust particles in the air reflecting the flash back into the camera lens. This is a problem with point and shoot cameras because the flash is so close to the lens.

evironmental settings for shutter speed and duration day or night or subject motion. maybe it is set for night in a dim but lighted place.

earlier i posted solution in similary problem. maybe help you this.

solution is good batteries, Ni-Mh or Lithium, rechargeable only not alkaline. but...problem is how long you watch pictures on lcd display or how much is flash in use. if always by shooting pics used flash that means that you can with best batteries 30, 20 or less pics shooted. and of course, if you connect camera with pc, how long is cam on? just transfer pics on pc and turn the camera off. the best solution is use the card reader for pics transfering.
if is flash off, it's possible to shot 120-150 pics with Ni-Mh. with lithium i don't know, maybe 500 pics. don't use camera lcd for analysing pics it's just there for short preview.
with alkaline batt., very low quality, i shot 30 pics without flash.

i shot also very good pics at night without flash. nikon coolpix L15 can do that but you must have more praxis. alkaline batteries shooting!
after 3 pictures on display is message: warning! the battery is exhausted. what you can do? turn the camera off. wait about 10 minutes. turn the camera on, you can shot 3 or 5 pictures and than turn your camera off again.
you can repeat this few times and you be lucky if you 30 pics captured:)
REMEMBER: all this goes without camera flash!!!
flash and every zooming use more battery power! and that was all magic:).

As a first step, make sure the batteries are fully charged and check in the Shooting menu if you have switched the flash to 'off' mode. Then check the shooting mode. In some shooting modes (like landscape), some cameras do not fire the flash. To check if the flash is working properly, change the mode to 'Night Portrait' and try to shoot. This mode is sure to fire the flash if everything is well with the camera. If still the flash is not working, take it to the nearest authorized service center.

The flash unit is for still photos only. By design it can not be used when shooting video, because it can not stay lit (the flash fires from a stored electrical charge, and needs time to build up another charge).

The shooting modes are described as follows: PROGRAM AUTO (Factory default setting) Program Auto mode is used for regular photography. The camera automatically makes the settings for natural color balance. Other functions, such as the flash mode and metering, can be adjusted manually. Portrait Portrait mode is suitable for taking a portrait-style picture of a person. The camera automatically sets the optimal shooting conditions. Landscape Landscape mode is suitable for taking pictures of landscapes and other outdoor scenes. The camera automatically sets the optimal shooting conditions. Night scene Night scene mode is suitable for shooting pictures in the evening or at night. The camera sets a slower shutter speed than is used in normal shooting. If you take a picture of a street at night in any other mode, the lack of brightness will result in a dark picture with only dots of light showing. In this mode, the true appearance of the street is captured. The camera automatically sets the optimal shooting conditions. If you use the flash, you can take pictures of both your subject and the night background. Self-portrait Self-portrait mode enables you to take a picture of yourself while holding the camera. Point the lens towards yourself, and the focus will be locked on you. The camera automatically sets the optimal shooting conditions. The zoom is fixed in the wide position and cannot be changed. QuickTime Movie QuickTime Movie mode lets you record movies. The focus and zoom are locked. If the distance to the subject changes, the focus may be compromised.