What would cause new fuse to blow when powering on (Sony STR-DN1030 Receiver).

Does the rest of the receiver work? Do you get audio output? If not, it could be the main power transformer. There is a thermal fuse buried in the core that if this opens, it will cause the unit to not power up completely.

When the main fuse blows on a sony, it is usually caused by shorted output transistors. You would have to replace these transistors before the unit will not blow the fuse and power up correctly.

The problem is the Power Switch. The switch on the STRDGF920 is very problematic. When the receiver is on very lightly move around the power switch with your finger. do not use enough pressure to turn the unit off. Just very lightly slide your finger over the switch and you will see your problem happen. I have two STRDG920 units with the same problem. One is so sensitive I can blow on the switch and it will power cycle off and on. I have called Sony and they said they do not offer a replacement part power switch. I will have to figure something out.

their are fuses, inside the unit, by the power supply area (transformer)

The most obvious place to check is anything to do with the power supply, such as the transformer. A fuse will only blow if an overload occurs, caused by something acting like it was just a piece of wire. However if something acts like a broken wire, everything justs stops dead and the fuse doesn't blow!

The fuse blowing is a symptom of something seriously shorted internally. What preceded the initial problem? Smoke is bad. Fire would be soon to follow without the fuse blowing. Take it to a tech.

Shorted power supply/module is most likely problem.

You could have a shorted winding in the power transformer. The diodes in the power supply can be shorted. Filter capacitors can short and send power to ground which will blow the fuse.

I resently hooked up my sony std d 565 reciever for 5.1 speakers and I keep hearing beeping, what is wrong?

This condition, may be produced by defective components (Q506, Q507). you can remove those transistor, replace the fuses, power-on and wait for relays click. if the fuses not blown again, them replace both transistor.