Look CAREFULLY within the younger lines (X3,30,35) and compare with the models X7,9,70,90,75,95.
With a careful comparison, you can easily find a second fan in older projectors. Which brings cooling air just to the part where the second diaphragm is located. This is done in order to eliminate overheating.
In addition, the second diaphragm must be adjustable. Homemade naturally can not.
Hence further problems arise.