horizontal output transistor

Horizontal Output Transistor In A Tv Board

Naturally you replace the shorted transistor with a new one and you power on the Television and it come up beautifully, and before you begin to celebrate the television goes down again(stop working)

You open the set and after checking the health of the same component (H.O.T) you find alas it is shorted again!!

This problem of H.O.T getting shorted immediately or after some times of replacement has given many technicians sleepless night trying to figure out what is happening here!!

In this article I am going to give you some tips on what to do to prevent the H.O.T from getting shorted after replacement.

To minimize the chances of the HOT getting shorted please make it a practice to change the following components directly every time you do H.O.T replacement.

high voltage tv circuit

A Typical High Voltage Circuit In CRT TV

High on the list is the snubber capacitor; this is also called the safety capacitor.

Sometimes it may also open, short or change its capacitance value and this always have effect on the H.O.T.

Next are the dry joints around the horizontal drive and output components, please make it a practice to do re-soldering around these components including the fly back pins, Horizontal drive transformer pins every time you find the HOT shorted.

The drive transistor should be replaced directly without even measuring it, sometimes it develop some leakage and hence cause the H.O.T to short after a period of time.

Also be sure to check the ESR of the filter capacitors involved in filtering the supply to horizontal circuits and if you suspect any just directly replace that capacitor.

horizontal drive circuit

A Typical Horizontal Driver And HOT Circuit

In some television like the JVC they incorporate some component on path to the base of the HOT (usually a Capacitor and choke) please be sure to replace them directly.

If still the HOT is getting shorted then finally you may have to change the fly back transformer or the horizontal oscillator IC is messed up and need replacement.


crt tv repair

CRT TV Repair By Humphrey


Electronics repairer based at Nairobi Kenya, Author CRT television repair Course, for more info please visit my blog at: http://www.humphreykimathi.blogspot.com

34 comments on “How To Prevent The Horizontal Output Transistor (H.O.T) From Getting Shorted After Replacement

  1. ram says:

    sir i have one problem, is that in my monitor the horizontal output signal from sync ic is not present but b+ is still present (the ic no is tda9112 ). so eht is noyt making. now what can i do to fix this problem?
    in collector of hot there48-52 volt but in base there is no signal.

  2. Chuppyh says:

    Can any1 tell what going on with my arcade monitor I put a new cap kit n
    It fix some of the pic but still got white jailbars the screen is to white cant ajust out thanks



  4. dalopez2nd says:

    Thank you so much for the golden learning's you give us!

  5. wilson cajolo says:

    hi sir..can u help my sharp tv 14" model 14v-k80m has sound but the picture is black. i can see the volume whe i adjust it and also the channel when i press it..can u help me what the components failed?

  6. wilson cajolo says:

    i opened the tv and the heater lits up..but when i lift up the h. output transistor and test its leg if it is shorted I found reading in my tester diode settings has continuity both side to side..is it busted? please help me

  7. ady says:

    thank you for the explanation and technique on replacing H.O.T, I had been servicing CRT, back home and have same problem, your explanation will be a great help for us

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