The printer powers on fine but wont read my 4gig sd card

The A402 works with MMC and SD cards. Your 4GB card is actually an SDHC card. While it fits into the slot, it is electronically incompatible. You need to use cards 2GB and smaller.

You may be restricted to using only SD cards, and many 4gb cards are actually SBHD. My sister had this problem with her camera and by putting in a new 2 gb SD card, her camera worked fine. You may need to shop online in order to find an SD card, but they're widely available online. It costs about the same for 2 2gb cards as one 4gb even though they aren't as convenient.

Have you tried giving the memory card and the memory card slot a good cleaning with a compressed air can?

Depending on the size of the card, some Digital Cameras can not read them...too big. If it's a 4gig or higher, your camera may not be able to write to it. Try a smaller Gig card and it should work.

If it does not seat (fit) properly, why say the printer will not read SD cards? It certainly will read SD cards that are supported. You can still upload to computer and print from there as you suggested.

The Z740 supports only MultiMediaCards & SD Memory Cards. 4GB and larger SD cards are usually SDHC (Secure Digital High Capacity) types - and bear the SDHC mark on the label. These cards are not compatible with this camera. Use only MMC and SD cards. SD cards are 2 GB and under - although *some* 4 GB cards are marked as SD too; these cards may or may not work. If you purchase a 4 GB SD (not SDHC) card, make sure that it can be returned if it doesn't work reliably in your camera.

Camera is not recognizing any memory card. The issue is with the camera electronics and not the cards.

I guess you put the SD adapter into the card reader right out of the box? You first may have to partition/format it after unpacking it. Under WinXP I can recommend an utility "DiskPart" which you can start from the command prompt (Run... -> cmd). For further instructions (if it sounds to you to be the problem ) contact me again.

Does the micro sd card been detected by your computer? If not, you may try other card reader, or other computer. If still does not detected, you may try to go to device manager and see whether the sd card is there, if yes, then you can assign a drive letter to the sd card.

Once SD card shows as a drive letter on PC, you can download sd card recovery software to get back your files. recommended asoftech photo recovery that helped me before. download it from link below
SD Card Recovery Software

You can refer to this card recovery tutorial
Recover files from SD Card

If above does not work, you may have to format the memory card (use quick format), and then use Asoftech Data Recovery to scan again the memory card and recover your files.

According to what I've read, you can double the original memory, but no more than that, so the max you can have on a Sansa e250 would be 4 GB (2GB internal memory and 2GB external memory). I also read that the micro SD cards holds
music only-no video.