HK 3380 Receiver - Power turns ON, then within a few seconds displays a PROTECT mode and immediately shuts off. I have checked speaker leads for shorting, etc. This unit was operating perfectly and then began this problem. I cannot seem to recover from it.

You aparently have a short somewhere in the speaker wires,

Do you hear the speaker protection relay click after about 10 seconds when you turn the receiver on? Does the display show PROTECTION on the display? These conditions indicate a bad channel that will keep the receiver from functioning but you still have lights. Steve

Hello Randy,
There are two options here: first, the power button is amber but unit still won't go. In this case try a 'factory reset' as per manual. If this won't work, it seems that the processor is gone (located on the display board) so you have to bring your unit into a authorized shop for repairs. Secondly, it might be just matter of some blown fuses which are located inside the unit on the transformer board. If after replacing (if they're blown) the unit still won't work or keeps blowing the new fuses, follow the first advice, meaning you have to bring the receiver to a service. To access the fuses, you have to remove the top cover.I wish you luck
Kostiko

Remove speaker wires and try again. If it still goes into protect mode, the problem is internal...shorted power transistors or some other fault. Check fuses also.

If the display does not turn on, then you have a power problem. The unit is not completely turning on. Since you opened up the unit, give it a sniff test to see if there is any burnt odor inside the unit. Check the fuses also. Have a look at the transformer board. It may have several fusible resistors sitting high on the board. If they burn open, there is no power to the display/cpu board.

The most common problem found on FixYa for Audio Video Receiver's is:

My receiver say's "Protect" or turns on then off. What's wrong? Seven times out of ten it is a shorted speaker or speaker wire. To determine your exact problem, the first step is to disconnect all speaker wires "at your receiver" Next: Turn the receiver back on. If your receiver still says "protect" or turns off, it needs to be serviced. If your receiver stays on; reconnect your speakers one at a time and power back up after each speaker. You may find that after reconnecting all speaker wires it works! Most commonly the small braids of wire from the + to the - have touched and have caused the problem. In some instances, you noticed the problem only when turning the volume up. either way, make sure the exposed wires to your receiver are no longer than 1/2" long and are completely under the screw down terminal or slide in. When you've found the wire or speaker with the problem, your receiver will go back into "protect" At this point, disconnect the wire from the speaker at the speaker that may be causing the problem then test again.* Note* Make sure speaker wires do Not touch each other as this Will cause a short! If you turn the receiver back on and it stays on, you now know the problem is in your speaker itself. To test your speaker, you will need a multimeter. Set it to ohms resistance and touch the speaker terminals, if there is a short internally the meter will read "1......" If it's an analog meter, it will peg to the right. There's your problem. Now, within any speaker there are quite a few possibilities as to what could be causing the problem. Most common is a blown coil and the speaker needs to be replaced. Some speakers have internal crossovers (usually floor standing speakers) and may have a shorted or burnt board (usually very visible brown burn marks on the board) and can possibly be repaired if your handy with a soldering iron. Now, if you disconnect the speaker wire at the speaker and it still says "protect" Check your wire for the obvious cut or nail thru the wire if possible. If your system has wiring that runs behind walls, you may need to use your meter again. Disconnect the wire at both ends, keep the ends separated, put your meter on ohms resistance and touch probes to the + and - wires at one side. If the meter pegs to the right or reads "1...." the wire is shorted and needs to be replaced or repaired at the short. Hope this helps.

Disconnect all speaker wires at the receiver then turn it back on. If it stays on, the receiver is ok and you need to reconnect speakers one by one and test by powering back on. Chances are good that a loose braid between the positive and negative posts are touching creating a short. This is one of the most common problems found. If your receiver still shuts off with no wires attatched, it needs to be serviced. Then you still need to check all connections. If you need further help with this issue, post a comment and I can help you troubleshoot further. Hope this helps.

Fastest way to check the receiver is to disconnect all speaker wires at the receiver and turn the unit back on. If it does not go into protect, your receiver is ok and you need to check all wires and speakers. If just one piece of braid on a speaker wire touches the other, it may not shut off immediately, however, as you turn up the volume the current level rises in the wire and creates a short. Thus, shuts down the receiver. If you need further help troubleshooting, post a comment and I can walk you thru it. Hope this helps.

Sounds like a bad output channel is causing it to go into protect mode. Time to see a repair tech.