I think the repairman that you talked to is mistaken......
You need to pull the dishwasher out, you maybe able to see if the springs are intact by removing the kickplate at the bottom.
One of the springs or plastic link that goes from hinge to spring maybe broken or you may just need new friction pads, (someone else on this forum just recently had one of these that the door wouldn't stay down and it ended up being the little rubber friction pads that go on the hinge arms so the door will stay at whatever open position you open it to.).
Most likely since your door just drops down real hard you are going to find one of the springs are loose from it's attachment points and it will be a broken spring or the plastic/nylon link that attaches the spring to the hinge.
Friction pads 8268961 http://www.repaircli.../8268961/941116
Edited by Budget Appliance Repair, 28 June 2013 - 06:08 AM.