There is a whirlpool Microwave (model:MH1150XMB4) in our apartment. Unfortunately, there is a crack in the door. Although the crack is only in the plastic frame of the door, the landlord asked us to replace the whole door. I checked the price: the door costs over 200 bucks! I am wondering if it's possible to replace the frame only. But I don't know where to purchase such a part. Thanks for your response and help!

Unfortunately, door parts are not separately available for this model.

You can get for less than $200 here.

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

Got the same problem. Still inquiring but I might have found a solution here : http://midwestapplianceparts.com/microwave-parts-537/whirlpool-microwave-parts-648/microwave-door-panel-663/whirlpool-microwave-door-panel-w-glass-4212.html
$79 for the panel only

Remove 3 screws at the end of the door and gently pry off from frame at that end. Be careful because clear glass is attached to frame. Remove handle for new door (install last). Remove silicone with razor blade knife as best you can all around glass clips. Then slide glass to the top or bottom (for most movement) so you can lift from clips (gentle prying only). Put new bead of clear silicone on new door glass connections and gently reinstall (cleaned) glass. Reinstall handle. Place new door on frame at hinge side first and gently press on. Screw in the 3 screws.