Question about Toshiba 27AF45 27" TV

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Hit by lighing

Two of the diodes are shorted, change all four out with higher spec. diodes. will not power up, any suggestions ? thanks

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Re: Hit by lighing

Check the fet Q502 (2SK3326), Ic504 the opto-isolator (PC817), and D517 for leakage. Use a dmm with diode testing - test froward then reverse, if you get any sustained readings both ways replace it with an NTE552. Also check R510 100 ohm....

Posted on Nov 27, 2007

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In panasonic modeltc-29sf3 pls give me the working voltage of zener diode with color code gray red red and red yellow in power supplyn section

just read the model and then google it, beside, if you short them, you need to replace them with same value, and this will be determined by the circuit, if you did not change the circuit - just buy two new diodes and install them, do not bother with voltages as they have some tolerance and type will determine it.

Jan 27, 2015 | Panasonic Standard (CRT) Televisions

1 Answer

No power on zenith z36x31d

The fuse may have failed. However, since you mention smelling something burning, you'll need to check if other parts (for example: a resistor or diode) also was damaged. That burning smell suggests that you had a short in the circuit and high voltage got past the fuse. If you insist on fixing the TV, you will need to identify any short and fix that before attempting to use it again.

I hope this helps.

Cindy Wells
(I've dealt with several resistor fires over the years. Sometimes the resistor or Zener diode is actually the fuse for the circuit. That simplifies the solution.)

Jul 11, 2014 | Zenith Z36X31D TV

1 Answer

Every time i turn on the tv it makes the click noise it is suppose to and the little red power indicater bulb flashes for about 5 to 7 secs like always but right about the time the screen usually kicks on...

Please check the horizontal output transistor for leak, base-emitter. Change it.If there is any kind of short in the board, the power supply will sense int and will shuts down. Line out put transformer [LOT] may also suspect. On the secondary supply stage from LOT, the secondary power supply section, check all the rectifier diodes, and its filter capacitors for leak. Even a slight leak will effect the proper function of the set. Check it with good qulaity analongue multimeter, with setting it to meg ohms range; check the suspected componets off board. Likewise check the primary rectified DC voltage at SMPS stage. It should be aroung 380V DC accross main filter capacitor. If it is not check the main filter capacitor [usually 330Mfd 450V] for low capacity. and check the four main rectifier diodes.

Oct 14, 2010 | Sony FD Trinitron WEGA KV-32FS100 32" TV

1 Answer


mostly this problem cause opto coupler is short. change the opto coupler and related parts like transistors,zener diode.and check all diodes&capacitors is power supply. you find any leaky or damaged part change it.
thank you

Sep 03, 2010 | Sharp 21B-S10 21" TV

2 Answers

Dead Set after power surge

Check the power supply transformer primary driver transistor and the associated components (some diodes and capacitors, resistors, an optocoupler maybe) and the rectifier diodes (or a bridge) and capacitors at the transformer secondary, what you are looking for is a short circuit, however, the short may as well be in another section of the circuit board (a shorted component may sometimes have signs of damage caused by heat, but this is not a rule).

Hope you can find out what it is...



Oct 01, 2009 | Standard (CRT) Televisions

1 Answer

Sony kv-32fs13 chirps and flashes

Hello 0279737,

This problem is caused by a shorted Horizontal Output Transistor. I would suggest that you have this TV checked by a qualified TV technician. This type of problem requires dealing with dangerous voltages, and repair should only be attempted by a trained technician.

I hope this helps

Thank you,


Oct 28, 2008 | Sony KV-32FS13 TV

1 Answer

Regulated Power supply

If the regulator is being shorted right after you replace it, I would say that you have a polarized part that is doing that. I would suggest to check all the diodes and capacitors around the power supply circuitry, There is a posibility that T601 is shorted internally, also check IC603 for s shorted condition..
Check this picture for the power supply schematic.d4d913d.jpg

Mar 14, 2008 | Standard (CRT) Televisions

1 Answer

No power

Solder any / all bad solder connects.While doing that,Look for
overheated areas in power circuits,caused by bad capacitors,
resulting in burnt/open resistors,shorted diodes,etc,.........T.

Nov 13, 2007 | Sharp 27H-S60 TV

1 Answer

Lightning Strike, Plz Help!

Hi. The red line on ICS is quite normal it does not mean the part has failed. To be honest in most cases if a tv has been hit by strike it is a right off & scapped. What I suggest is to remove the main pcb & power supply pcb if its seperate & inspect the print side of pcb for signs of arcing tracking or burnt track. Repair any damaged track by cleaning off the coating to get at clean copper then solder wire accros to bridge the damage. Check the power supply resistors diodes transistors look carefully for any burnt components or components which are physicaly damaged. Check the line output transistor this will be near the large transformer with a thick red ht lead going up to the crt. Check all the components you can in the line stage look at all the ICS to ensure none of them have holes in them or have blown apart. Hopefully you find some or one if your very lucky that is damaged replace it & try your tv.

Sep 23, 2007 | Toshiba CZ36V61 TV

1 Answer


Could it be in the HV circuit? first you isolate h/output section from power supply. make power supply output ok. check h/output section for short circuit 1 print short near eht 2 diodes or cap.near eht 3 yoke H winding just by removing connector 4 EHT transformer regards

Sep 12, 2007 | GE 25GT270 TV

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