SX-316-S auto tune - Pioneer SX-315

check the attached service manual.
H appears normal and L appears to be defect.
also see page 88 to troubleshoot further Pioneer SX 316 Service Manual

Hi Ray,
Here is a very simple link for connecting speakers to your receiver:
Start on page 11
Good Luck,
JP
Pioneer SX 316 Operating Instructions Manual Connecting The Speakers

Many subwoofers accept both line level (RCA jacks) and amplified inputs (+ and - speaker terminals). The Pioneer SX-316 does not offer line level output, only amplified outputs via the PURPLE + and - speaker terminals. This means that in order to use any subwoofer with an SX-316, the sub woofer will need to accept a + and - speaker wire connections for input Your manual speaker connections are on page 11 of the manual which can be found here: http://www.manualslib.com/manual/260358/Pioneer-Sx-316-S.html#manual

Starting at the rear of the SX-316; run a speaker wire from the PURPLE + and - terminal (SUBWOOFER) to the + and - speaker input terminals on the subwoofer. See your subwoofer manual or experiment (at your own risk) with connecting the speaker wire from the SX-316 to the subwoofer's + and - LEFT only, RIGHT only or BOTH left and right speaker inputs. Do not connect wires from the SX-316 to the speaker OUTPUT terminals of your subwoofer.

Finally, adjust any variable low pass filter knob or setting on the subwoofer to the lowest frequency that your main speakers are capable of producing. If you're not sure what that value is, try setting the subwoofer to 100Hz and judge how it blends with the main speakers. If it seems a little too bass heavy and thick then reduce the setting to 80Hz. On the other hand, if the sound seems to be slightly thin and lacking weight, try increasing the setting to 120Hz. By careful listening and a bit of patience you will be able to get the sound to seem balanced and well blended.

Good luck!

Mine is having this problem now.

Tried re-inserting the speaker wires.
Tried resetting before it shuts off.
Tried disassembling but solder joins are still nice.

It still shuts off soon after power up. Time to spend money? :(

Did you try a search engine "pioneer SX-316 manual"?

http://audio.manualsonline.com/manuals/mfg/pioneer/sx316s.html

Turn it down to 1/4 while troubleshooting or you may destroy your speakers after you find that button, whatever it is.

Has it NEVER worked or did it suddenly start acting this way?

Do ALL sources act this way or only one(some)?

I'd look for a the Mute button or a Tape monitor incorrectly selected.

DVD audio straight in from its highest quality audio output. Use the stereo audio output to run straight to the TV for casual watching through TV speakers without the Pioneer involved.

A TV is just a glorified night-light, not a sound source - get its related audio from the Cable Box, ditto the highest quality

Check the resistance of the primary on the main power transformer, (with power off) should be 1-3 ohms. If open you need a new transformer.

If good turn it on and check for ac voltage (120v) there.

try turnind down the sub from the amp itself it might be putting out more volts than the subs input can handle check your standing wave feature to make sure the trim is not up too high