JVM1490 IS BEEPING EVERY 4-5 MIN ONE BEEP

There is no battery in a microwave. I can't see how it could still beep for more than a few seconds. Check the kitchen for for another source of the beep. Like a smoke alarm with a weak battery.

Its beeps whenyo food stll inside so you must take it out when its finish warming

try and press the stop and clear button twice

The problem is in the keypad control board, replacement is the only option to remedy the situation, if you decide to repair, check the price of the part first.

/turn it on 4-5 sec it shuts down display still lites unpluged for a min. tryed again same thing

THE ARCHING IS DUE TO EXPOSED METAL AND WILL BURN UP MAGNETRON IN MICROWAVE. TIME FOR NEW

if it beeps you might as well just unplug it

Try first unplugging power cable for ten minutes, and see if it clears the error.

Looking at the owner's manual, it would seem that the beep is supposed to occur at one minute intervals when cooking is completed. You may need to press the CANCEL pad to make it stop, but I would assume you shouldn't have to. I would assume that when the control panel senses that the door has been opened, it should stop beeping. It sounds like the code in the microprocessor has been corrupted, but only replacement of the chip would fix that. The owner's manual is online at: http://org.downloadcenter.samsung.com/downloadfile/ContentsFile.aspx?CDSite=SS&CttFileID=33043&CDCttType=UM&ModelType=N&ModelName=MW1280STA&VPath=UM/200304/20030418120018750_1_MW1280STA.pdf ( a better URL is http://tinyurl.com/ybpwlm ) You might consider calling Samsung support at 1-800-SAMSUNG (1-800-726-7864) Mon-Sun: 9am-9pm (EST). Good luck.