I have a Magic Chef microwave model mco153sf. The

Read online or download manual:
http://kitchen.manualsonline.com/manuals/mfg/magic_chef/mco153uw.html

Cylindrical fuse is located inside a cylindrical casing (approx. 2 inches long), found suspended amongst the wiring.

The fuse is NOT fixed to a circuit card nor another fixed point in the microwaves, as is common with other microwaves.

IF YOUR OVEN IS IN WARRANTY, GET MANUFACTURERS AUTHORIZED SERVICE; IF NOT, THE MAGNETRON IS THE SINGLE MOST EXPENSIVE PART IN THE OVEN

Most likely your touch pad has gone bad. Unplug the microwave for a couple of minutes. plug it back and see if its stick stuck. Since you've only had it for a little over a month. I suggest that you contact your manufacturer. If the touch pad needs to be replaced, they should do it at o cost to you.

On many Magic Chef models, press the Help button to bring up the menu. Choose the number for Child Lock (I think it's #1), then choose 2 to turn Child Lock off.

The manual for the Magic Chef MCD1311ST Microwave can be downloaded in pdf format from the following site (follow the link then click the "Manuals" tab):
http://www.mcappliance.com/mwodetailpage.aspx?ModelName=MCD1311ST

If you don't have time to download, here's what the instructions state:

SETTING THE CLOCK
When the oven is first plugged in, the display will flash ":0" and a tone will sound. If the AC power ever goes off, the display shows ":0" when the power comes back on.

1. Touch CLOCK pad.
This is a 12 hour clock system.

2. Touch CLOCK pad once more.
This is a 24hour clock system.
NOTE: This oven has multiple clock system. If you want 12 hour clock system, omit this step.

3. Enter the correct time of day by touching the numbers in sequence.

4. Touch CLOCK pad.
The display stops blinking, and the colon start blinking. If you selected 12 hour clock system, this digital clock allows you to set from 1:00 to 12:59. If you selected 24 hour clock system, this digital clock allows you to set from 0:00 to 23:59.

5. Touch STOP/CLEAR pad.

NOTE: If you attempt to enter an incorrect time, the time will not be set and a error signal tone will sound. Touch the CLOCK pad and re-enter the time.

try gliding your fingers over the touch pad to see if any other buttons work , #8 is stuck, or shorted

Try this site, it has the best advice on almost ANY microwave problem you can have, I know I read something almost identical to your prob. here:
http://www.repairfaq.org/sam/micfaq.htm.

The control lock shuts down the control panel pads to avoid unintended use of the microwave oven. To unlock/lock control, the microwave must be in standby mode, touch and hold stop/clear for 3 seconds until one long tone sounds and the display clears to show an outline if the display area. Repeat to unlock control, and return display to the time of day, if any pad is touched while the control is locked, there will be no response from the microwave oven. hope this helps.

I don't have Magic chef, however, I would try hitting cancel, unplugging the microwave and waiting a few minutes, then plugging it back in to reset it. Alternatively, you could go to your manual under troubleshoooting. I wish that I could help you more with this. Good luck to you. Please let me know if you figure this one out.