Left speaker (as I face unit) has ceased to function. Any reasonable solution?

if the speakers are 10 years or older they might need replacing

The center output connection is 100% gone try to google local workshops that fix electronics - ususlly a chap fix

hi, you may have caused an upset to the data flow from face to main pc board. try disconnecting the unit from the vehicle for a day, then reconnect it the next day. or find the reset procedure for your unit, it will either be a small micoswitch behind the face, or a sequence of holding down some switches to activate the reset function. if the problem persists then the unit mite have a cracked main pc board, a faulty face unit, or the mute function is continuously running. to solve these faults you will have to consult with a technician.

HI:
Usually when a receiver goes into protect mode, there are several reasons, One is there is a bad speaker connected to the unit, this will cause the unit to to into protect mode, try disconnecting all speaker from the unit and turning it on if it does not go into protect then one of the speakers are bad. Another reason is the power output Amplifier IC is shorted inside the unit. Another reasons could be that speaker wires are touching each other and causing a short. Disconnect all unit connecting to the unit and try turning on, if it stays on and no protect then connect them including the speakers one at time until you determine which is causing the error. If it goes into protect with nothing but the unit on then the Output IC is bad and the unit needs servicing.

For that particular unit, it does not seem to be a recurring problem-- though a certain channel (or input) ceasing to function on a receiver does happen from time to time. If you find out that the speaker is okay, you can look into getting the receiver repaired.

Setting the Time
1. G-Shock watches feature a digital display that is set using the function buttons on the outside of the watch face. To set the time, press and hold the the upper left button until the seconds unit blinks on the display. Reset the seconds to "00" by pressing the lower right button.
   
   Push the lower left button to switch to the hours unit, which will start blinking. Advance the hour by pressing the lower right button. If you hold down the lower right button, it will advance the hour unit at a higher rate of speed. Once the hour is set, press the lower left button to switch to the minutes unit. As with the hours unit, pressing the lower right button will advance the minutes and holding it down will advance the minutes rapidly.
   
   Once the time is set, press the upper left button to save the setting.
Backlight
2. The backlight on a G-Shock watch has a manual control and an automatic function that will light the face of the watch whenever the alarm, countdown alarm or hourly alarm ring. To use the manual backlight, press the button on the bottom of timepiece. The light will glow for approximately 2 seconds before going out.
   
   The automatic function is set by pressing and holding the lower right button. When the automatic function is set, an indicator icon will display on the watch face above the seconds unit. You can turn off the automatic backlight function by pressing and holding the lower right button until the icon disappears.
   
   Note that backlight causes a drain on the battery, and overuse of the backlight will greatly reduce battery life.
Setting the Alarm
3. The G-Shock has an alarm that emits an audible tone for approximately 20 seconds when it turns on. To set the alarm, press the lower left button until "AL" displays in the upper left corner of the timepiece. Press and hold the upper left button until the hours unit starts to blink. Adjust the hour by pressing the lower right button. As when setting the time, you can advance the hour at a higher rate of speed by holding down the lower right button.
   
   Once the hour unit is set, press the lower left button to advance to the minutes. Use the lower right button to set the minutes. Follow these same instructions to set the month and day you want the alarm set.
   
   When the alarm time and date are entered, press the upper left button to save the setting. Push the lower left button three times to return the G-Shock to "Timekeeping" mode.

Setting the Time
1. G-Shock watches feature a digital display that is set using the function buttons on the outside of the watch face. To set the time, press and hold the the upper left button until the seconds unit blinks on the display. Reset the seconds to "00" by pressing the lower right button.
   
   Push the lower left button to switch to the hours unit, which will start blinking. Advance the hour by pressing the lower right button. If you hold down the lower right button, it will advance the hour unit at a higher rate of speed. Once the hour is set, press the lower left button to switch to the minutes unit. As with the hours unit, pressing the lower right button will advance the minutes and holding it down will advance the minutes rapidly.
   
   Once the time is set, press the upper left button to save the setting.
Backlight
2. The backlight on a G-Shock watch has a manual control and an automatic function that will light the face of the watch whenever the alarm, countdown alarm or hourly alarm ring. To use the manual backlight, press the button on the bottom of timepiece. The light will glow for approximately 2 seconds before going out.
   
   The automatic function is set by pressing and holding the lower right button. When the automatic function is set, an indicator icon will display on the watch face above the seconds unit. You can turn off the automatic backlight function by pressing and holding the lower right button until the icon disappears.
   
   Note that backlight causes a drain on the battery, and overuse of the backlight will greatly reduce battery life.
Setting the Alarm
3. The G-Shock has an alarm that emits an audible tone for approximately 20 seconds when it turns on. To set the alarm, press the lower left button until "AL" displays in the upper left corner of the timepiece. Press and hold the upper left button until the hours unit starts to blink. Adjust the hour by pressing the lower right button. As when setting the time, you can advance the hour at a higher rate of speed by holding down the lower right button.
   
   Once the hour unit is set, press the lower left button to advance to the minutes. Use the lower right button to set the minutes. Follow these same instructions to set the month and day you want the alarm set.
   
   When the alarm time and date are entered, press the upper left button to save the setting. Push the lower left button three times to return the G-Shock to "Timekeeping" mode.

Well besides the obvious of voice off/on the speaker could be blown. I have one of these units but have not cracked it open. My speaker has blown twice on my passport 9500i and I just replaced it myself. It's out of warrantee and Escort wouldn't send me a speaker, so I got one from radio shack and that worked for a while, then blew. I used a laptop internal speaker now and that works great ! BTW if the speaker on this unit is soldered to the board good luck, like I said I haven't cracked my ew3100 open yet.

Here's the quote from the manual regarding "dcer": "The speaker wire has a short-circuit or touches the chassis of the vehicle and then the protection function is activated. Wire or insulate the speaker cable properly and press the reset button. If the "PROTECT/DCER" code does not disappear, consult your nearest service center "

I believe the manual can be downloaded from crutchfield .com after you go to the Kenwood KDC-138 page on their website. The reset button is either on the lower left of the face or, removing the face, on the lower left of the body. Hope this helps you.

Hi Dave. I guess it would be helpful to know model of the system. Could you send us the model number and make? If I have this information I can get you up and going!