Lewis I had this problem a while back and posted to the PDML. I got a reply from a member - whose name escapes me now - and I took the precaution on saving his reply which I paste below. You can order the latch/door from Pentax - it is quite inexpensive - and fit it yourself.
There are two screws in the foot that need to come off, and one covered up behind the cosmetic panel by the "test" button, the cosmetic needs to be peeled back. There are two more screws at the rear of the base that the head rotates on that I think need to come loose as well...you will need to rotate the head to get to them. There is no need to remove the two forward screws. This should loosen the front and rear of the flash to allow room to tilt the old battery door out and the new one in. Hope this makes sense. I would add, be careful that you don't lose the plunger and spring that pressurise the door, they come flying out as you prise the body apart if you're not careful. I have repaired my two 280's with no problems. Anton
