MAGELLAN ROADMATE 700 ON THE FRITZ.

The unit is drawing too much power and is being protected by a current/temp sensitive device that shuts down to protect unit. When it cools, the power is restored until it heats up again, and the cycle continues.

Sounds like something in the power supply area is the cause of the anomaly.

The amp protection circuit has been activated. Remove the power cord from the wall outlet immediately. Disconnect all speaker cables and input sources, and leave the AV receiver with its power cord disconnected for 1 hour. After that, reconnect the power cord and reconnect an input and a pair of speaker wires onto the unit. If the receiver still does not turn on than you will have to bring it in for service. Turn up the volume and if the receiver doesn't shut down, power off the receiver and add another pair of speakers. Power up the unit again and turn up the volume. If it doesn't shut down, power off the unit again. Now connect all your input sources and turn on your receiver. If the unit shuts down again, your unit will need to be further serviced at an authorized Onkyo service center.

The amp protection circuit has been activated. Remove the power cord from the wall outlet immediately. Disconnect all speaker cables and input sources, and leave the AV receiver with its power cord disconnected for 1 hour. After that, reconnect the power cord and reconnect an input and a pair of speaker wires onto the unit. If the receiver still does not turn on than you will have to bring it in for service. Turn up the volume and if the receiver doesn't shut down, power off the receiver and add another pair of speakers. Power up the unit again and turn up the volume. If it doesn't shut down, power off the unit again. Now connect all your input sources and turn on your receiver. If the unit shuts down again, your unit will need to be further serviced at an authorized Onkyo service center.

The amp protection circuit has been activated. Remove the power cord from the wall outlet immediately. Disconnect all speaker cables and input sources, and leave the AV receiver with its power cord disconnected for 1 hour. After that, reconnect the power cord and reconnect an input and a pair of speaker wires onto the unit. If the receiver still does not turn on than you will have to bring it in for service. Turn up the volume and if the receiver doesn't shut down, power off the receiver and add another pair of speakers. Power up the unit again and turn up the volume. If it doesn't shut down, power off the unit again. Now connect all your input sources and turn on your receiver. If the unit shuts down again, your unit will need to be further serviced at an authorized Onkyo service center.

It may cause it to shut down if it's a safety thing, but it sounds like the compressor's faulty to me.

The amp protection circuit has been activated. Remove the power cord from the wall outlet immediately. Disconnect all speaker cables and input sources, and leave the AV receiver with its power cord disconnected for 1 hour. After that, reconnect the power cord and reconnect an input and a pair of speaker wires onto the unit. If the receiver still does not turn on than you will have to bring it in for service. Turn up the volume and if the receiver doesn't shut down, power off the receiver and add another pair of speakers. Power up the unit again and turn up the volume. If it doesn't shut down, power off the unit again. Now connect all your input sources and turn on your receiver. If the unit shuts down again, your unit will need to be further serviced at an authorized Onkyo service center.

To obtain service, take or ship your Onkyo product to an Onkyo Authorized Service Center. Please also include in any mailing a contact name, address and telephone number. Please include a copy of the original sales receipt/invoice as well as a letter stating what the problem is, with your name address and phone number so the service center knows who to return the unit to. Please note, before shipping, you must contact the authorized service center to inform them that you will be sending your unit in for repair.

Is there a CD left in the drive by any chance?

This thing has a time lapsed lockout feature so if you try too many times to input the code it will lock out the inputs for so many minutes or hours.  You gots ta try again to input the codes after the unit unlocks itself and lets you try again, but if you repeatedly keep trying without success, then the unit will erase and destroy all the data it holds. This is a setting that can be turned on or off once you gain access to the ipod.  Pretty cool James Bond sh.t hunh?  
You can bypass having to wait and just restore the unit back to factory default and and remove the pass code feature.

I had the same issue and tried changing inputs and etc. within a second of time. Nothing I did worked until, I opened the lower front access door and twisted the effects knob around quickly. This stopped it from turning off and it has been functioning normally since. Even turning it off and on again is without the issue coming back. I did try most all the buttons previous to doing the effects knob, in case that makes a difference in the long-run.

Before the issue you are having started on the unit I was working on, the owner of this unit did say he was having an issue earlier with the monitor SVideo jack in back, having a role in it powering off like this, about 6 months ago. To make it work then, he would remove the SVideo cable from the monitor jack, turn on the unit and then put back the SVideo cable once the unit was on and working. This allowed it to work for several weeks to a month before turning itself off again. He would repeat this procedure and it would work fine again for awhile.
Could be an electrical or grounding issue via SVideo that messed things up more and more?

Hope this works for you too!!

Replace the lamp as that is most likely the suspect