It should be noted that the lens cap problem WILL make the focus APPEAR as if its faulty, that is if you can see anything at all! as with the lens cap issue the symptoms can totally vary between camcorders, sometimes its a blurred image and on others either no image at all, or if there is one it can be streaky or have colored lines across the image etc etc. Speaking as an engineer, my personal feeling is that you did NOT have another fault, and that there is a great possibility that certain element of dishonesty is being used by wherever you had the repair done for purposes of making the job pay, this idea backed up by you saying that before the lens cap problem all was OK.