Apple has offered to replace faulty on-off buttons on the iPhone 5, a glitch that the company said on Friday affected "a small percentage" of the smartphones. Apple said on that "iPhone 5 models manufactured through March 2013 may be affected by this issue," in which the sleep/wake button stops functioning or works only intermittently.

Owners can type in their iPhone serial numbers on Apple's website to see if their phones qualify for a fix, then either take their gadgets to a store or mail them in to be repaired.

For customers in the US, the replacement program starts today. For those in other countries, the fix will be available May 2. Users can either take their phones to Apple retail stores or other official Apple dealers, or mail them in.

Seperately, Samsung on Sunday said that a limited number of its flagship Galaxy S5 smartphones shipped with non-working cameras. The defective phones show the message "warning: camera faile" when the camera is turned on, and no pictures can be taken.

"We have discovered that the issue has been seen in a very limited portion of early production Galaxy S5 units, and was caused by complications in the ROM (Read Only Memory) component which stores the information necessary to operate the camera," Samsung said in statement.

Samusng did not specify the number of phones affected but said the problem had been reported in the United States and a few other countries.

Samsung's customers affected by the S5 camera failure should contact Samsung's customer service or the mobile service provider.