I am not able to turn on denon 1603 receiver without remote, it is there on a stand by mode

SOURCE: When I turn on my denon 3200 receiver it keeps

Generally speaking, an amp protects itself from heat, shorts and overloads by refusing to turn on or stay on.

Overloads can be from excessive periods of high output and shorts would be wiring issues or a speaker blowing up.

You should be able to feel if it's hot. WHY is it overheating? Make sure it has sufficient ventilation on all sides and that vent holes are not blocked by dust balls. Ensure the fan (if equipped) is running as designed (some only operate on demand). Clean dust and debris from it.

If the amp comes back on after cooling, you're lucky. They only have so many self-protection cycles in their lives so continuously resetting or cycling their power without addressing the cause can do more harm than good.

If it protects immediately on a cool power up you should disconnect the speaker connections and try it 'naked'. If it comes up then diagnose which lead(s) are shorted. If it does not come up the problem is internal and should be left to an experienced hands-on tech.

SOURCE: Denon AVR 1603 goes to stand by mode

It has a blown channel, unless you are good at repairing them I suggest an authorized Denon service center. This Denon not only needs the shorted output transistors replaced, but a few resistors, a couple of driver transistors and a capacitor on the preamp board as well. alot of parts to be replaced. I have repaired about a hundred of these over the last few years and my shop charges about $200 for this repair, other shops should be about the same.

SOURCE: Denon AVR-1707 Receiver - remote stopped working

please apply a new fresh battery to it-confirm from right orientation(polarity)-try to apply a contact cleaner spray over the bad button and press it many times.-remove any thing between remote and receiver.-you can use universal remote and confirm befor you buy the new remote that it support your receiver.

SOURCE: Denon RC-978 remote... every button shuts receiver off

Drop the front panel of your receiver,there is ZONE 2 ON/OFF switch.
Good day!
solutiondoct

SOURCE: I have a Denon AVR-1603 Receiver and Direct TV

Did you ever figure out how to do this? I have a Denon avr-1803, and also cannot control the volume from my Direct TV remote using the codes listed on the Direct TV system. Thanks for sharing any information you have found.