A buddy of mine has a Dish 500 (I think) with a 625 receiver. This morning there was no tv, just trying to acquire a signal. This happened a few weeks ago. The common thread is that it snowed overnight on both days. If there is snow on the dish will that affect the signal? Would you expec to loose the picture? Is there anything else that can be checked prior to climbing on the roof and brushing off the dish?