Thermal fuse needs replacing.

Not sure where you are located but here is a UK source. http://www.4daewoo.co.uk/microwave/kor-630a/fuse-hv/product.pl?pid=103747&path=108334&model_ref=214555

please go www.fitness.manualsonline.com
God bless you

Hi,
Here is a tip that will help you to figure out what is wrong with yourMicrowave Oven....

Microwave Oven Basic Troubleshooting Tips

heatman101
'
'
';
'';
';

1. Touch the CLOCK pad. This will activate the 12-hour system. (To activate 24-hour system, tap once more)
2. Enter the correct time of day by touching the time set panels.
3. Touch CLOCK pad.

You will know that you're changing the time when your display stops blinking and and the colon starts blinking.
If you have any other questions regarding your Daewoo KOR-630A, I located an online manual for you.
Cheers!
http://dl.owneriq.net/6/64d0773e-ca06-4c23-97b1-e039cfc523aa.pdf

There are a couple of good used controller assemblies for sale here:

http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=260417312468&rvr_id=136767326417&crlp=1_263602_263622&UA=WXF%3F&GUID=bf6d4e6f1260a02652f11e01ff7ed56c&itemid=260417312468&ff4=263602_263622

Or just look for eBay itrem # 260417312468.

Hi I have bought an oven and wanna know how can i set the power level.

You can visit Daewoo online or call them at 877-393-7823 or 973-249-3448 to find parts.

We're happy to help you with free advice and we'd appreciate your thoughtful rating of our answer.

YOu can get the manual from below link
http://etech.maiila.com/daewood-microwave-oven-kor-630a

how old is the machine, microwave ovens have a tendancy to do the ridiculous for no possible reason. a check of the main power fuse within the unit might help. it is a large fuse 10A> that supplies the transformers

Download the manual here:

http://www.nodevice.com/user_manual/daewoo/microwave_oven1/kor-630a.html