II usually have a signal strength of 70 and am fine from about 8 AM until sometime between 13:30 and 2 PM when the service will go down on "signal strength" which shows 15. After unplugging my HN 7000S modem the service will return and work fine for up to 20 minutes until it happens again. This goes on until 5:30- 6PM when service returns and stays good until the following day around the same time. I can troubleshoot this system almost as well as the Indian techs who can only say my antenna is not pointed correctly. However they have no answer when I tell them this happens with a signal strength of from 68 to 70.
It is possible there is some type of interference if is happening the same time every day. Your dish is probably pointed correctly if it cuts out with a signal of 70. Other possibilities are modem, LNB or even coax connections, anything is possible with electronic equipment. Myself I would go through the system starting with all coax connections (taking apart is the only way) and check the grounding also. The LNB would be checked that no water is in the feedhorn and the mylar cover is clear. I can't give any more advise without knowing the satellite and frequency your on.