My onkyo xt sd575 receiver has a very soft sound. i have to turn up the volume to hear something. there are no settings setted up wrong as i have already checked.

The 0-83 error indicates a problem with the firmware update.

Try resetting the receiver's BIOS by following these steps2:
Unplug all cables
Un-Power the receiver
Power the receiver
Before the receiver gets into the "Enter for updating" message, press Tone + CBL/SAT + ON/STANDBY. This will show you either the volume numbers or get you into settings of the receiver's speaker configuration.

Press CBL/SAT + ON/STANDBY. This will clear the BIOS and show a "Clear" message on the display. Wait until you hear a couple of clicking sounds for the receiver to turn on and off the power.

TX-NR555 Owner's Manual - Onkyo Product Support (onkyousa.com)

First of all, be sure the volume is down fairly low so that you don't blow the speakers or the unit itself if and when the sound suddenly comes back. I've repaired many units whose owners turned them way way up to try to hear something, then flipped off a tape monitor or mute switch and got blasted. No sound with any input? (tuner, CD, etc.) Do you hear ANY noise or hiss from the speakers at all? I hate to ask, but are the speakers and inputs connected properly? On this model, the jacks are not set up beside each other as they usually are. Instead, the left channel speaker and input jacks are above the right channel jacks. This can be confusing! Are the speakers actually selected? The proper speaker select switch (below the power switch) must be in the down position. Is it possible that someone left a headphone adapter plug in the headphone jack? You know, the kind that allows you to use headphones with a 1/8" plug in that 1/4" jack? This will cause the speakers to be shut off. If you don't have the owner's manual, it's at http://www.intl.onkyo.com/downloads/manuals/pdf/tx-sr500_manual_e.pdf If none of this helps, the unit may have a problem and I would invite you to write back with more details on what you've tried, etc.

please try to manifactory setting first. for most ONKYO receiver, hold "VCR/DVR" button, press STBY, after unit power on.

Yes it is normal, the 608 is a THX certified receiver, so it goes by THX reference levels.

In theory once you have run the Audyssey auto-setup with the included mic the proper reference level for watching movies will be 82 if the volume number scale is set absolute or 0dB of it is set to THX relative. At this setting the volume should be the same as watching that movie at the theater. I have mine set to power-on at a level of -30dB which corresponds to level 52 on the scale you have it set to. This is a comfortable lowish level, but I turn it up to at least -10dB AKA 72 when watching movies.

Cleared all AV settings and reprogrammed.

It's the Tape 2 button - unclick it.

I have to ask the obvoius, did you get the manual, have you used the onscreen menu to set up the speakers, you can calibrate the speaker levels on the TV screen if you use the S video or RCA vidoe connection .have you turned off tape monitor?

The receiver automatic speaker set-up set the sub volume at -12 and since it was not getting any signals from the receiver it was doing what it is supposed to be doing (going to the standby mode). This was troubleshooted by Onkyo tech support on a Sunday. All the best about Onkyo customer support.

I figured out the problem.  After you set the individual channel volume for each speaker you need to push the test button on the remote and this will lock in the settings.  Thanks.

You can download the manual from the link below: http://www.intl.onkyo.com/downloads/manuals/pdf/tx-ds787_manual_e.pdf c. Power On Volume This sets a designated volume setting for the TX-DS787 to be set every time that the power is turned on. This prevents the TXDS787 from being turned on while it is set to an extremely high volume and suddenly output very loud sounds. For the absolute volume display method, this can be set between min and max. For the relative volume display method, this can be set between ?? and 18 decibels. If you do not mind having the TX-DS787 turned on with its current volume setting, set this to "Last." Please update the question & let us know if the information given was useful to you - Good Luck!