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Main fuse blows

As soon as i plug the tv into the wall the main fuse blows.

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Re: Main fuse blows

If still under warranty or if you have no electronic repair experience you should take the set back to the shop or to a repair person. Some of the solutions described below can be dangerous, TV's are very hazardous to service. Even when plugged out, TV's can store very high voltages. Horizontal output possibly shorted, &, or voltage regulator, could also have bad caps in the regulator circuitry, & resistors. Pix tube can also blow the power supply. You'll have to do some troubleshooting to locate any bad parts, bare minimum you'll need a decent multimeter and soldering equipment.

Posted on Apr 23, 2006

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Re: Main fuse blows

You may have a surge protector called a thyristor that is shorted right on the main a/c line. Or the main power supply has a major nasty short as the bridge rectifier the filter cap or the degusing coil.

Posted on Apr 20, 2006

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In my tv fuse is blowing off immediately

If fuse blows off immediately, i means that there is a short circuit occured in your telivision. This can mainly due to some diodes or regulators inside your tv. An overvoltage, spikes, ie [sudden high rise and go low], in the supply votage in your home, could damage power supply regulator components inside your tv.
All Sony Tvs has high accuracy power regulating systems inside. It is an onboard assembly, usually take 1/4th of the area of the TV. In older Sony TVs, this section was built in with use of transistors of different types. But your tv is not so old, so its power supply system is built with an STR, an Ic meant only for power regulations. Normally it willb numbered STR S6707, STR S6703 etc; according th the working voltage of the main board, and screen size of the TV.
This STR may get shorted due to power fluctuations, or any other reasons. A I mentioned above this is an Ic look like small squuare biscut of about an inch in square, and will be black in colour.
The rectified main power supply is given to it via an SMPS transformer [Swiched Mode Transformer], and the Ic will swictch it on and off at the rate of sbout 25KHz or more, and this transformeres secondary voltage is used to power up the other part of the ciiruit board.
If the fuse is blowing as soon as the set is switched on, this Ic will be faulty [Shorted inside]. If you put an another fuse, it also will blow up due to short. It is not good to play with power supply system by doing this as it may harm to other components also.
You have done it I thinks. Here in India, we gets 220VAC as home power supply. Sony TVs used here have a fuse rateing of 250V 3.5Amps. If your household supply system voltage is also this you must put only this rated fuse. If it is 110 or 120VAC, the fuse rating may differ; and will go upto 6 to7 Amps. More than this rated fuse should not be used.
You just do one thing. Just open the back cover of the TV, locate the power regulator section, and chech whether any main rectifier diodes for leak. There may four of them. In some sony Tvs, rectifier stalks are used. Check it for leak. If thery are all good, measure the resistance across the main filter capacitor with a multimeter set in Ohms range. If the STR said above is short, the meter will give full scale deflection. Unsoder the STR and pick it out after loosing its fixing screws to the heat sink. Again check the resistance accross the main filter capacitor. It must sho a low deflection or no deflection at all. Never replace the STR with a new one as there may be some other faulty components in that section. Usually when STR fails, there are some Zener diodes, Wire wound resistor etc will also gets shrted. If you replce the STR before checking them for fault, the STR you puts in will get shorted as you swich on the set. It will take just 1/100 part of a second.
So check all the components related with power regulator system, and then only repace the regulator. Caution: Keep chlidren away from you while you open the tv. Never touch any part of the circuit board while power supply is there. Plug out from the wall socket each time you touch the printed circuit board. As your Tv screen size is 32", an approximate of 25KVDC [15,000VDC], will be present at the first anode of the picture tube while it is working. It is too dagerous to contact.
If you haven't through knoledge, skill and patience, never try to repair it. If you knows to follow its schematic digram, buy one book and follow the circuit.
Keep an adult beside you as you try to repair your set, as a precaution.
If you have any doubt, report to Fixya, they will give me alert. Ok

Oct 20, 2010 | Sony FD Trinitron WEGA KV-32FS120 32" TV

1 Answer

No Power

all sets must have rated fuse for protection. some units now use what is called a PICO-FUSE.this type of fuse is soldered into the pc board. usually marked with location i.d. F301,F901,F400. etc. these fuses look like resistors or in-line coils. check continuity w/ohm meter. if new fuse blows as soon as you plug in tv, suspect bridge diode ciruit or main filter cap(large ripple filter by main fuse. if new fuse blows when you try to turn on, suspect 130v regulator or high voltage short(horizontal-output, flyback transformer) good luck!

Feb 20, 2009 | Standard (CRT) Televisions

2 Answers

Blowing fuse

Check for bad caps or diodes. Look for anything discolored or burned.

Dec 11, 2008 | Memorex MT1131 13" TV

1 Answer

Blows fuses repeatedly on IWT3206 model

when electrical storm was going on the t.v. was on ? if it is was then return electrical / heavy lightning it may burn the parts.shorting through your mains and anteena conections, please clarify

Jun 24, 2008 | Standard (CRT) Televisions

1 Answer


Hi there!

Dead short in the power supply, possibly the rectifier or the PTC has failed. PTC located in the Primary supply at the point where the coil around the tube plugs into the Main board. Two terminals to be exact. Normally cream in colour if it is an original Philips PTC. If the rectifier is short you may expect to have more items blown. Good Luck, Regards, JUS004

Mar 22, 2008 | Philips 27PT5441 27" TV

2 Answers

Main fuse blown on CT-32G11 32" Panasonic TV, Replacement fuses continue to blow.

If the main fuse keeps blowing, check the horizontal output transistor for a shorted condition and diodes in that section as well.

Jan 12, 2008 | Panasonic CT-32G11 32" TV

2 Answers

Proscan PS32610

Tv keeps blowing fuses it is due to short ckt in your tv in 1 power supply. 2 horl output section it is mainly due to 1 switching transistr 2 main fil cap 3 rectifier diodes 4 print short 5 h/output tra. 6 eht transformer

Sep 25, 2007 | Proscan PS36810 TV

1 Answer

Blowing Fuses

main rectifier could be shorted, main regulator could be shorted MOV surge supressor is probably shorted. MOV will be a little disc close to the power cord input (after fuse).

Jul 31, 2007 | Sony KV-32FS13 TV

3 Answers

TV does not turn on

If you have no indication of power(no lights,no clicks) the main fuse is a good place to start but if he is blown and is black in color you will have a shorted component ahead in the circuit and if you replace the fuse it will blow up as soon as you plug the set in,in all honesty since you are not too familiar with tv service you should be safe and seek the assistance of a servicer.

Oct 13, 2006 | Sony KV-32S26 32" TV

1 Answer

TV won't power up and blows the fuse

A 10 year old RCa most likly has a bad Horizontal output transistor as well as the main High Voltage transformer and The transformer is no lonmger available from RCA. The replacement wont last longer then a year if your lucky. My advice on a set this old ?? Buy a newer one!!

Sep 11, 2006 | RCA F35670MB 35" TV

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