My tv turns off when I am watching tv
The number of blinks from the standby LED on the front indicate specific error codes and possible fault conditions.
(from an article on understanding Sony TV error codes):
Many of the later model Sony TV's have a built in self-diagnosis function. If the timer/standby indicator is blinking, this could be an indication of a problem with the unit. The diagnostic blinking will occur automatically with no action required by you to engage it.
The timing of the blinking you see would be as follows: two to nine blinks, (depending on the fault), about a third of a second apart, then a pause for 3 seconds, then the two to nine blinks about a third of a second apart again.
Here is a list of the problems that might have occurred indicated by the number of blinks.
* Unit is dead, No blinks - Problem in the standby power section. Might check fuse, R607, Q601, IC601, R612 and VDR601 (should show open).
* Continuous blink once a second, no pausing - No reply from the jungle IC301 (data bus is busy, shorted to ground, or held high), IK video path is defective.
* One blink - not used for the self-diagnosis
* Two blinks - B+ over current protection (OCP), unit goes to the standby mode then displays the 2 blink fault. Could be a short in the power supply of any of the circuits.
* Three blinks - B+ over voltage protection (OVP), unit goes to the standby mode then displays the 3 blink fault. This is also a problem in the power supply circuit, check T603 and R672.
* Four blinks - No vertical Deflection (V STOP), Screen goes to a single horizontal line then the video signal muted. Check IC1509, Q1505
* Five blinks - AKB circuit (automatic kine bias), the timer/standby indicator blinks for about 30 seconds then goes to the self-diagnosis function. Something is wrong with the video. Check video out, Q705, 732, 761 and other components on the C board, also check Q218, 219, 220 on the A board. In addition, unit could be in IK blanking, try turning up screen slightly.
* Six blinks - No Horizontal (H STOP), no raster, goes to the blinking self-diagnosis function immediately. Check C515 & 516 and the jungle IC, IC206.
* 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.
* Eight blinks - Problem with the audio (AUDIO), unit goes to standby and blinks the self-diagnosis code. Check IC406 audio amp, PS401, and 402. On some projection models of Sony TV sets, this code means that T8005 (flyback transformer), or the associative components in the high voltage circuits are defective on the D board.
* Nine blinks - Replace D 6116 and D 6301 on the "G" board, do not resolder as this will fix the problem temporary. Or Panel Module Error or Thermal Error. If it is intermittent 9 blinks, meaning sometimes the TV comes on and other times you get flashing, then change the switching regulator on the "G" board or check connections. Make sure the regulator is -12 or -13 (negitive).
* Ten blinks - Check Q8014 and Q8013 for shorts, leakage, or bad solder connections on the " D" board. If the transistors are bad, check R8051 and IC8005, also on the "D" board.
If this is a CRT TV, it could prove expensive in terms of repair, as if it is shutting off and the standby LED is blinking, it means the set has entered protection mode, due to one or more components shorting or going leaky. Horizontal output transistor and flyback transformer are the most likely culprits to cause the set to shut off while you are watching it so check those first along with any suspicious looking components in the power supply (bulging or crooked electrolytic capacitors, diodes, resistors that look discoloured, etc.) and measure what you can if you have access to a digital and analogue multimeter.
If you have some basic experience and knowledge of electronics, and you understand the potential risks involved, you can have a go at fixing it yourself. Unless you really know what you're doing, and have the confidence to match, I do not recommend this practice.
You can however, do some simple visual checks of your set which don't require any special tools. Start by checking the power supply and working your way toward the horizontal stage; and make sure when replacing the flyback transformer, that the correct part number is ordered and fitted for your model - using the wrong type can either be underpowered, resulting in a dull picture, or no picture at all, or the set simply won't start up.
The same applies to the horizontal output transistor - this is important - it must be the correct rating for your set, along with the correct pin type and orientation (you can check these details on the original parts in your set as a guide to suitable replacements).
Use the wrong type and you will do more damage. Horizontal output transistors have a tendency to go off with an almighty BANG as do chopper transistors in power supplies if they are replaced with underrated or cheap equivalents, so that's something to keep in mind when replacing this and unless you get the manufacturer recommended part, the reliability factor can be anywhere from excellent to nil.
It's also a good idea to check the tuning capacitors on the collector circuit of the horizontal output transistor, as these may have dropped value over time, and replace (with correct type and voltage rating) to prevent risk of expensive/dangerous pyrotechnics and irreparable damage in the future.
When repairing the horizontal stage in any CRT TV, and such involves replacement of the flyback transformer, the horizontal output transistor and tuning capacitors must also be replaced at the same time.
When repairing the switchmode power supply in any CRT TV, all electrolytic capacitors must be replaced at once, and any leaky or open circuit diodes, transistors, and resistors must be checked and replaced accordingly.
*Don't forget to touch up any dodgy solder joints on the chassis just to be sure after replacing the flyback transformer, horizontal output transistor, and tuning caps. Most bad solder joints would exist around input sockets, the function buttons and the ON/OFF switch on the front so check these as well.
Hopefully your set will work a little better after that. If not, put it aside and consider a newer TV with extended warranty (covering you against any defects, faults, and so on).
The best bet is to obtain some quotes if necessary on the likely costs to fix this first and then weigh up the pros and cons of those - you can then choose to go ahead and get it repaired properly by a qualified service tecnhician (if you don't want to fix it yourself) or cut your losses and buy a new set.
Feb 11, 2013 |
Sony FD Trinitron WEGA KV-34HS420 34" TV