How JustAnswer Works:
  • Ask an Expert
    Experts are full of valuable knowledge and are ready to help with any question. Credentials confirmed by a Fortune 500 verification firm.
  • Get a Professional Answer
    Via email, text message, or notification as you wait on our site.
    Ask follow up questions if you need to.
  • 100% Satisfaction Guarantee
    Rate the answer you receive.
Ask Shahid Your Own Question
Shahid
Shahid, Technician
Category: TV
Satisfied Customers: 10099
Experience:  I have been repairing electronic gear since 1993 as a qualified Sony tech
33243543
Type Your TV Question Here...
Shahid is online now
A new question is answered every 9 seconds

Toshiba 46xv645u. Plugged in, no standby light, no picture

Customer Question

Toshiba 46xv645u. Plugged in, no standby light, no picture or anything. cant seem to detect any reading anywhere...stdby volts, tv on, nothing...have what CERTAINLY looks like a blown resistor, judging solely on the discoloration...but I dont know how reliable that is to judge that way, so I need some direction.
Submitted: 2 months ago.
Category: TV
Expert:  Shahid replied 2 months ago.

Hi, my name is ***** ***** I will do my best to help you today. To make sure I don’t miss anything, please give me a minute to review your question.

Expert:  Shahid replied 2 months ago.

So no standby volts reading at all on power supply board?

Expert:  Shahid replied 2 months ago.

Ed, please check the main fuse and a fuse I circled in yellow on power supply board, if fuse is OK but no standby volts output then power supply board is defective.

Customer: replied 2 months ago.

Huh. Thats a goofy lookin fuse. So i have to take the board off to test that one, looks like. The glass fuses on front were okay. Let me remove board and chk that one...theres also another 9fnthose at F880 ill chk as well. F870, F840. Ill chk them out. This is the resistor i was talkin about

Expert:  Shahid replied 2 months ago.

Resistor shown in picture is 47 ohms 1/2 watt.

Customer: replied 2 months ago.

Do you think that discoloration is indicative of a blown resistor? And if so...inwill test it, but if so, how would i find a mathlching one on a donor board...are there markings on the resistor, or on the board? Or would i have to get the schematics for the donor board...

Expert:  Shahid replied 2 months ago.

Please check the color rings on resistor, you would need to find a resistor having same color rings on other boards to get replacement one.

Expert:  Shahid replied 2 months ago.

Discoloration of board shows heat effect and resistor seems not affected.

Customer: replied 2 months ago.

Gotcha. I tested all those fuses, all fine. I tested this resistor, and it tests blown, i think. It reads continuity beep both ways... reading .086 both ways. Whereas another resistor reads .5 one way, 0L the other eay...which i THINK is more like a correct reading. Anyway, if I can find another resistor with same color rings...is there an orientation it has to be mounted with, I'm guessing? And how do i determine that orientation?

Expert:  Shahid replied 2 months ago.

No no, take out one pin of resistor from board, set your meter to Ohms reading and check what ohms reading appear on meter.

In circuit test of resistor doesn't help.

Customer: replied 2 months ago.

Gotcha. Ill check my in circuit meters and see if one of them had a diode/resistor check, that would b nice. But ya...when i get home, I'll pull a pin and check it. When i get with ya again, i have like maybe 4 more new questions, max, and then i need to fillowup on like 10 or 12 of them that we left hanging from before and i dont think you got paid on, but those are already in your cue, so we wont have to worry about being online at the same time when i open the questions, cause theyll just be reopening the old ones. I'll be home in approximately 9 hours, and online and working only for maybe 3 hours max at that point....lol, im tired, need to catch up on sleep after that and some repairs.

Expert:  Shahid replied 2 months ago.

Yeah, let see if in-circuit meter works and at least one pin out of circuit test of that resistor will confirm it.

We will keep working on pending questions.

Thanks.

Customer: replied 1 month ago.

So it should measure a circuit one way, and OL the other way, right?

Customer: replied 1 month ago.

you're absolutely right, brother, reads different. reads .082v both ways

Customer: replied 1 month ago.

so all fuses and capacitors are good on this board, as well. ON the main board for this unit, I don't feel any obviously failed capacitors.....also, there is no 5v.

Expert:  Shahid replied 1 month ago.

You mean same resistor shows 0.82 ohms?

Customer: replied 1 month ago.

Correct

Customer: replied 1 month ago.

And it's actually .082...could have swirn it said volts, but the meter is and was set to ohms for fuse testing and the like

Expert:  Shahid replied 1 month ago.

Color pattern on resistor shows it is 47 ohms. Please click following link to view resistor color code calculator that will help you to get resistor value by adding color pattern..

http://www.sengpielaudio.com/calculator-colorcode.htm

Thanks.

Customer: replied 1 month ago.

Cool, thanks, ***** ***** chart. I went and got replacement resistors the other day, will solder in the new one here in a few minutes

Expert:  Shahid replied 1 month ago.

OK, take your time.

Customer: replied 1 month ago.

Swapped the resistor. And no luck. So when plugged in, all voltages measure zero. When pressing the power button, or not pressing the power button, the POW_TV lead fluctuates between 0v, and 0.1v.

Expert:  Shahid replied 1 month ago.

0 and 0.1V change isn't noticeable and should be approx 2~3V to switch On the power supply.

Customer: replied 1 month ago.

So fuses were good, and still no voltage....you said this means its the power supply? What do i do to proceed on testing the power supply?

Expert:  Shahid replied 1 month ago.

While power cord is plugged in, power board should provide standby volts even all connectors are off, do you get standby volts reading?