Sony KV-36FS76U Fault Troubleshooting

The Sony KV-36FS76U had an extremely advanced chassis consisting of a microcomputer system. This was essentially one of the last designs utilising microcontroller subsystems, and one of the most difficult to repair. If you still have one of these old television sets then it is highly uneconomical to repair it, as the main components such as the tube and LOPT are difficult to source.

Entering Diagnostic Mode

This television has extensive diagnostic capability, and you can figure out what has gone wrong without even opening it. To enter the set into diagnostic mode do the following:

1. Switch OFF using the front power button.
2. Hold PROG- and PROG+ buttons down simultaneously and then switch the ON using the front power button. The PROG buttons are on the top panel of the set.
3. Release both buttons on the top panel after 3 seconds.
4. You should see "TT--" on the upper right corner of the TV screen.

CRT Useful Life

Whilst in diagnostic mode, entering 99 on the remote control displays the monitor error screen, which will display the number of hours the cathode ray tube (CRT), has been in use.

If a shop display used the set for 5 years × 24 × 365, then the number of hours the CRT was in use is 43800. If your TV is showing between 20,000 hours to 30,000 hours, then your tube is very likely past its useful life period.

Cathode ray tubes generally have a short and limited useful life span since a CRT is essentially a valve component. The electronic characteristics of this component will change over time due to heat to the cathode and oxidation of the electron gun elements such as the grid and anode. When the electronic characteristics have changed and moved outside the predetermined safety margins, the LED blinks 5 times and the television enters into a standby mode. This is when you need to look online for a new television set. You can get some good deals from online shops these days.

LED Blinking Diagnostic

The Sony KV-36FS76U has provision for troubleshooting by way of the front LED lights blinking. The number of times the LED blinks gives an indication to the type of fault. If your television starts to blink, then it indicates a serious electronics issue, and you are better off looking for a modern television receiver.

Blinking Telly

If the LED blinks 2 times, then this indicates over-current protection issues; check the following components on D1 board, Q8102, Q8103, Q8106, IC8801, or better still, buy a new television.

If the LED blinks 4 times, then this indicates vertical deflection circuitry has failed. Check the following components on the D1 board, R8207, R8206, or better still, get a new telly. This could also be because IC1701 on board A has failed. This IC is difficult to change; therefore, a new television is in order.

Tube Failure

When the tube is past its useful life period, the LED blinks 5 times and enters into standby mode. The Automatic Kine Bias (AKB) circuit, which consists of the AKB chip, performs the circuit testing. This circuit optimises the CRT drive conditions and is often near the RGB circuitry. The AKB circuit makes sure that the cathode heater as well as anode charge and internal tube impedance are within safe margins before the circuit switches ON the higher voltages to the tube.

This error is an indication of a worn out or faulty tube. As a safety precaution, the manufacturers have created a safety system to prevent the set from powering if the tube is not operating within safe specifications.

Buy a New Television

When the LED Blinks 5 times, it essentially means that you need to buy a new modern television. Do NOT attempt to repair it or waste time opening it. This is one of the most complex chassis ever designed, and a qualified experienced professional follows the safety advice.

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