Question about Toshiba 42H81 42" Rear Projection Television

1 Answer

Toshiba 42h81 power light turns on no blinks and no picture checked fuses there fine had a burnt resistor under heat sinc replaced it ic chips are ordered i can hear the speaker cones when its turned on quick thump so that should be working does this point to more of a power issue? or can a ic chip make the set not power on the guns

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  • makitaman Sep 02, 2008

    ive replace the ic's with same ones stk-110

    resistor was a 1.8 ohm 1 watt location r7720

    ive checked all the fuses multiple times

    im at a point where im gona have to start testing power with the meter. need to know the best way to meter these locations



  • makitaman Sep 02, 2008

    where do i find the nuetral side?

  • makitaman Sep 02, 2008

    i tested the power on the ic's using 1 as ground i metered pin 4 and 5 on each ic and got a .3 volts reading

  • makitaman Sep 02, 2008

    correction on the resitor location it was r7711

  • makitaman Sep 03, 2008

    ok ive tested to all kinds of shields and get nothing on both sides of fuses
    but i got voltage on both sides of main fuse
    fuse locations i tested were f850 f851 f852 f853 f490 f870 f891
    i c 2 more in the high voltage side f860 and f801 that i havent checked yet.

  • makitaman Sep 03, 2008

    801 is the main been tested hot

    and 860 has been tested meters closed and no voltage either side

  • makitaman Sep 03, 2008

    801 is the main been tested hot

    and 860 has been tested meters closed and no voltage either side

  • makitaman Sep 03, 2008

    f801 is working

  • makitaman Sep 04, 2008

    i tested the voltage on power up to see if any is present in the first few seconds and have found no voltage. from the relay i get 2 fast clicks then a 3rd. the 3rd i belive is the power on. when you plug it in it the power light comes on automatically on 3rd click.
    and again no power from tuner shield to any of the fuses both sides

  • makitaman Sep 05, 2008

    ive checked the diodes on the power supply as well

  • makitaman Sep 07, 2008

    i rechecked all the solder joints on the ic everything is good



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STK392-110 's = replace with Toshiba or Sanyo quality only..
What was the location & value of the resistor ?
An IC, if shorted internally,can prevent the tv from powering up..
Re-check soldered in 5 amp micro fuses F850,851,852,etc
Fix it ! ..............................T.

Posted on Aug 29, 2008

  • Vista Electronics Sep 02, 2008

    With circuit diagram, check + & -- voltages from power supply

    area to convergence STK's....

  • Vista Electronics Sep 05, 2008

    recheck solder points on both IC's for shorted pins together...T



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1 Answer

My Toshiba 42H81 has no picture and has a red blinking light by the power button. Still have the audio from my Tivo coming in but no picture!

If it shuts off and then the power light starts blinking red or if it never gets picture and the power light blinks red constantly that is usually indicative of the convergence ICs (STK 392-110). You never want to replace the ICs without also replacing the resistors that are associated with them. There are usually 6 resistors, one for each of the colors and there corresponding direction, IE Red horizontal, red vertical, blue horizontal, ect. You will find them right where the STK 392-110 ICs are. Right in front of them. You can get the parts from They carry the ICs and the resistors. If you do not feel comfortable completing this repair I could do it for you if you send me the board. My email address is: Cost = 375.00 and that includes all parts.
Good Luck.

Jun 25, 2009 | Toshiba 42H81 42" Rear Projection...

1 Answer

Convergence issue, replaced convergence chips, now blinking red power light and no picture

Recheck all of your solder connections for bridging and cold solder joints. Check the large output resistors under the heat sink and the smaller ones to the left of them. Check all of the fuses on the power board. And make sure that you check all of your connectors carefully. Also check that you didn't pinch a wire somewhere.
I am not being mean by saying that if you could power up before then more than likely the power up issue was caused by something you did.

Jun 03, 2009 | Toshiba 50H81 50" Rear Projection...

1 Answer

STK IC CHIP 392-110

I made the same repair in a Toshiba 42h81 I replaced the STK 392-110 and after a lot of searching found the cheaper ones last 6 month or so be sure to use Sanyo IC's and replace the resistors with them when the IC's let go they take the resistors out I posted my repair On my page if it will help you

Dec 02, 2008 | Toshiba 42H81 42" Rear Projection...

1 Answer

I have a Toshiba 42H81 that has the power indicator light blinking and the TV will not turn on

Replace the convergence amps and check the return resistors in path to the yoke from that circuit.

William Rayburn, CET
Premium Technologies
PO Box 442
Long Beach, WA. 98631

Oct 14, 2008 | Toshiba 42H81 42" Rear Projection...

1 Answer

No power

Replace Convergence IC's STK392-110 and any burnt resistors
& check fuses F851,852,853,etc.........................T

Aug 11, 2008 | Toshiba 42H81 42" Rear Projection...

3 Answers

Toshiba 50h71 red light after fixing the convergence chips

Did you check to be certain none of the resistors were burned or open that power the ICs ? This is fairly common for one or two of the convergenvce resistors to be open when the ICs go out. Also double check the iC pins to insure that none of the pins are bridged with solder. If you need more assistance please let me know.

May 19, 2008 | Toshiba 50H71 50" Rear Projection...

1 Answer

Toshiba 42h81 replaced IC's now flashing red light and no picture

first of all take the board out and back sure all the pins are soldered and that one didnt get pushed up out of the way.
then check for solder bridges where you would have solder more than one pin together.
then check the resisters in the circuit that they are all good and then check to make sure everything is plugged in correctly

Feb 04, 2008 | Toshiba 42H81 42" Rear Projection...

1 Answer

Toshiba 42H81 problem set won't turn on

This repair is for technical skilled only.....
1) Pull chassis
2)Replace open fuse(s)
3)Replace Convergence IC"s
4)Solder specific bad connects

Please read my previous posts concerning convergence repairs.
Or provide Make,model,age and symptom.............T.

Jan 03, 2008 | Toshiba 42H81 42" Rear Projection...

1 Answer


which of these parts were know to be bad?
are you sure your soldering is good on the IC's?
check hv output transistor see if shorted, kinda follow this thread see what you find.

Dec 19, 2007 | Toshiba 42H81 42" Rear Projection...

1 Answer

No picture no sound and power light blinks.

Did you check the supply fuses to the convergence ICs? Did you check the output resistors
other wise i would replace the convergence ic first.

Dec 08, 2007 | Toshiba 50H81 50" Rear Projection...

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