Sony KDL22EX308 Audio Troubleshooting, Power Supply Troubleshooting, Completely Dead Set, CTV-68

Chapter 3 - Troubleshooting

Audio Troubleshooting

Since all audio signals are input, processed and amplified by the BAL board, any issue involving the loss of audio or audio distortions which is present at all inputs would dictate that issue is remedied by replacement of the BAL board. It is possible that a software update might be required but it is very unusual for this to affect all sources. Once again, check with the Sony technical support website regarding this issue.

Audio problems that are input specific (especially the HDMI and digital sources such as the USB input and tuner) are more likely to point to the need for a software update and this is especially true if the problem is intermittent.

Power Supply Troubleshooting

Failures in the power supply circuits that prevent the unit from turning on are caused by one of the following scenarios:

•Complete failure of the standby and main power supplies

•Failure of the main supply including the main switching regulator, PFC circuit, main relay and other components required to turn the circuits on.

•The power supply is not receiving a turn-on command from the

CPU

Completely Dead Set

A complete power supply failure is generally the result of severe transients in the AC line such as those incurred during an electrical storm. The EX308 model line utilizes a red standby LED located on the lower left front bezel that is lit whenever the unit is receiving AC power and is turned off. The KDL32EX308 model incorporates an “eco” switch located on the lower right side which removes all AC power from the unit and produces the same symptom of a unit that has been unplugged or lost its AC power. This switch should be checked first whenever the standby LED is not lighting. This switch is not available on the KDL22EX308.

Won’t Power On

This situation assumes that the red standby LED is lit when AC power is applied to the unit. A lit standby LED indicates that the standby power supply is operational, and the CPU on the BAL board is at least partly operational. In this case it is likely that the main power supply is either not being turned on or it has failed.

Service Tip: If the standby LED is lit but the unit will not power on, remove AC power from the unit. This can be done by unplugging the AC cord or turning off the “eco” switch. Wait about 20 seconds and re-apply AC power. You should hear a distinct click of the main relay which will engage for about 5 minutes, 20 seconds before releasing again. If the relay clicks on, the power-on command line from the CPU is functional. Use the power- on button on the right side of the unit to attempt a turn-on and eliminate a defective remote control system. The troubleshooting flowchart in Figure 3-4 will assist in isolating the power problem.

ECO

SWTCH

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