Sony trinitron power will not come on sometimes

Seven blinks - High voltage shutdown. The high voltage has exceeded 33k and the unit goes immediately into safety shutdown. Check power supply regulation and horizontal circuits. Power supply regulator section circuit should be troubleshooted. It is fatal to proceed trouble shooting this section, without proper knowledge in electronics, as if you want to measure the voltages to this section, the TV must be switched ON. When it is switched ON, or powered up; most of the components in this section will be dangerous to touch. If you are not handy, seek tech support. It will be more better.

The primary power supply is good,maybe the horizontal output transistor is deffective thats why there is no high voltage supply in the picture tube because theflyback have no supply voltage and oscilation.So check the harizontal output transistor and replace if deffective.

Hello Fixya Customer,

Thank you for your question.

Based on your symptoms, there could be several possibilities. The power supply, deflection, and high voltage circuit.

A common fault is in the High Voltage power supply circuit, and it can be corrected by repairing or replacing the main board.

Thank you for using Fixya, and if you should have any additional questions, please ask.

try making resolders on power supply ckts, try also adjust screen voltage,, check crt socket,,if all of this dont solve it, try to rejuvinate the crt.

You probably have a main or high voltage power supply problem; the latter produces the 20,000 plus volts for the CRT and gets its voltage from the main supply. It's difficult to say which is at fault without a few measurements.

Hello c_car,

What is happening is that the Shutdown Circuit is turning the TV off due to excessive current flow. The excessive current flow is most likely the result of a problem in the HV (High Voltage) section of your TV. This could mean that the Horizontal Output Transistor or the Integrated High Voltage Transformer has malfunctioned (developed a short circuit). I would advise that you let a qualified TV technician work on the set due to the nature of this problem.

I hope this helps,

Thank you,

Shuttle83

http://www.electron-age-technologies-llc.com

I have not worked on your particular model. But, I have serviced many TV sets over the years. My answer will ge generic.

Check all the capacitors in the horizontal output stage and power supply areas for high ESR. All the caps that are out of spec must be changed.

The high voltage multiplier & flyback can also cause the fault you are having.

You have to consider that the DC voltages are not the only important spec that has to be met. There are also many power drive signals that work with reactive devices. If there is any defect in the critical areas there will be failures.

Jerry G.

My 36 wega did the same thing last week it must be contagious. Blinks 7 times mostly but sometimes 6 if hit power switch again. The problem is the D-boards shorted Flyback high voltage transformer but the ones Sony is selling $130 do not hold up and seem to burn out in a few days, yes twice bitten. Finally they send me new D-board can't wait to see if this fixes it once and for all. The board costs around $200 but is worth it to get it running again.

This may be a power supply, and or a high voltage, or a scan ampplifier failure. The set would have to be properly trouble shooted by an experienced TV tech to determine the exact failure. This is not something you can fix yourself at home.

Jerry G.

I would think that this TV has some colder solder joints around the high voltage area and the power supply as well. Check mainly the high power resistors area.