Toshiba TV not powering on? - Page 2

Senatov · 08-06-2012, 11:40 AM

Ok, he said it started around 150, when the power was pressed jumped to around 290, then 140, then 150 again. Still no screen and no light.

ben7 · 08-06-2012, 11:42 AM

Quote:

Originally Posted by Senatov

Ok, he said it started around 150, when the power was pressed jumped to around 290, then 140, then 150 again. Still no screen and no light.

Seems like it shuts down due to overcurrent, I bet one of the sustain boards is shorted. Is there any cables that feed power directly to the sustain boards from the PSU?

Senatov · 08-06-2012, 11:45 AM

Quote:

Originally Posted by ben7

Seems like it shuts down due to overcurrent, I bet one of the sustain boards is shorted. Is there any cables that feed power directly to the sustain boards from the PSU?

What would the sustain board look like?

tom66 · 08-06-2012, 11:51 AM

There are no sustain boards in an LCD TV

. That is plasma only. I think it is more likely there is some shutdown mechanism that is activating. Your best bet would be to test the power supply outputs; there might be one that is out of spec. Also visually inspect all connectors, reseat them well. Try without the DVD player too.

ben7 · 08-06-2012, 11:54 AM

Quote:

Originally Posted by tom66

There are no sustain boards in an LCD TV

. That is plasma only. I think it is more likely there is some shutdown mechanism that is activating. Your best bet would be to test the power supply outputs; there might be one that is out of spec. Also visually inspect all connectors, reseat them well. Try without the DVD player too.

LOL!

Well, nobody ever mentioned if it was a plasma or a LCD, so I just guessed plasma by the age/size of it.

Senatov · 08-06-2012, 11:58 AM

Yes it is an LCD. The output from the PSU appears pretty constant. I don't think that any of the connectors could have become loose, as the TV sat on the cabinet all this time. The one thing that is kind of inconsistent is the clicking noise. When I plug it in, there is a click. When I press power, there are 2 clicks, when I press it again, there is one more click, and when I unplug it, there is a click. This clicking never happened when the TV was working. I would have heard it as the clicking is very loud.

ben7 · 08-06-2012, 11:59 AM

I would bet its one of the switching supplies on the board at the top, with the small heatsinks and small yellow transformers.

selldoor · 08-06-2012, 12:07 PM

Are you guys just forgetting the shorted PJ63 problem - mentioned earlier - there are a number of threads regarding this issue- the seine board is quite expensive to replace (if you can find one) and for a 7 year old set may not be economically viable.

ben7 · 08-06-2012, 12:09 PM

Quote:

Originally Posted by selldoor

Are you guys just forgetting the shorted PJ63 problem - mentioned earlier - there are a number of threads regarding this issue- the seine board is quite expensive to replace (if you can find one) and for a 7 year old set may not be economically viable.

Why exactly does it short out?

It looks like it would be possible to fix, if its the connector itself.

Senatov · 08-06-2012, 12:09 PM

Quote:

Originally Posted by selldoor

Are you guys just forgetting the shorted PJ63 problem - mentioned earlier - there are a number of threads regarding this issue- the seine board is quite expensive to replace (if you can find one) and for a 7 year old set may not be economically viable.

The PJ63 problem from my research was most always accompanied by a blinking red light. For me, the red light does not even come on.

Senatov · 08-06-2012, 12:10 PM

I have identified the source of the clicking:

http://www.badcaps.net/forum/attachm...1&d=1344276648

ben7 · 08-06-2012, 12:11 PM

Quote:

Originally Posted by Senatov

The PJ63 problem from my research was most always accompanied by a blinking red light. For me, the red light does not even come on.

Perhaps it has shorted out, when you said the light was blinking, then the next time you turned it on, it might have made a voltage regulator blowup or something like that.

Senatov · 08-06-2012, 12:12 PM

Quote:

Originally Posted by ben7

Perhaps it has shorted out, when you said the light was blinking, then the next time you turned it on, it might have made a voltage regulator blowup or something like that.

The light always blinks while the TV is powering up, and then shuts off when it is on. It blinked as it usually does, but then the set went out all of a sudden, now nothing happens other than the clicks.

ben7 · 08-06-2012, 12:13 PM

Quote:

Originally Posted by Senatov

The light always blinks while the TV is powering up, and then shuts off when it is on. It blinked as it usually does, but then the set went out all of a sudden.

Oh ok.

I think the clicking your hearing is coming from the two relays next to the yellow PFC choke you pointed out.

ben7 · 08-06-2012, 12:19 PM

I have attached a pic of the PSU.

I circled the relays I was talking about.

I also circled a connector which I presume is carrying ~300v DC, it probably goes to the backlight inverters. Try unplugging that and see if it turns on.

Senatov · 08-06-2012, 12:23 PM

Ok, I will try in a minute. I am actually working on my irrigation system at the moment. I am having a busy day off. Why do you think that the clicking did not happen when the TV worked?

multimeter · 08-06-2012, 12:28 PM

op,you said the caps were checked with a multimeter?analog? digital?,the only check you can do with a dmm,of analog meter is a kick test,and capacitance measurement,it wont confirm if the caps are high esr,are all the outputs stable?and at there correct voltages?

ben7 · 08-06-2012, 12:29 PM

Quote:

Originally Posted by Senatov

Ok, I will try in a minute. I am actually working on my irrigation system at the moment. I am having a busy day off. Why do you think that the clicking did not happen when the TV worked?

Well, it should click on when you press the power button. It might happen as soon as you press the button, so maybe you have just thought it was the sound of the actual power button clicking.

When our samsung plasma broke, it kept power cycling, and the relays kept clicking every few seconds. Two transistors later and some soldering, it was fixed.

I'm not so sure anymore that the connector goes to the backlight inverters. Most likely they are on the sides, under the perforated metal covers.

Senatov · 08-06-2012, 12:31 PM

Quote:

Originally Posted by ben7

Well, it should click on when you press the power button. It might happen as soon as you press the button, so maybe you have just thought it was the sound of the actual power button clicking.

When our samsung plasma broke, it kept power cycling, and the relays kept clicking every few seconds. Two transistors later and some soldering, it was fixed.

I'm not so sure anymore that the connector goes to the backlight inverters. Most likely they are on the sides, under the perforated metal covers.

Ok, I tried it. The clicking stopped with that unplugged, but the TV still does not turn on. Still no red light. I really appreciate the tremendous support.

ben7 · 08-06-2012, 12:32 PM

Quote:

Originally Posted by Senatov

Ok, I tried it. The clicking stopped with that unplugged, but the TV still does not turn on. Still no red light. I really appreciate the tremendous support.

Yeah, I thought so.
After careful looking at the pics, that seems to be the main power input from the filtering board next to/below the PSU.

08-06-2012, 11:40 AM	#21
Senatov Member Join Date: Aug 2012 City & State: Boston, MA My Country: USA I'm a: Knowledge Seeker Posts: 50	Re: Toshiba TV not powering on? Ok, he said it started around 150, when the power was pressed jumped to around 290, then 140, then 150 again. Still no screen and no light.

08-06-2012, 11:51 AM	#24
tom66 Badcaps Veteran Join Date: Apr 2011 City & State: University of Leeds (MEng ElecEng undergrad) My Country: UK Line Voltage: 230Vac 50Hz I'm a: Student Tech Posts: 13,452	Re: Toshiba TV not powering on? There are no sustain boards in an LCD TV . That is plasma only. I think it is more likely there is some shutdown mechanism that is activating. Your best bet would be to test the power supply outputs; there might be one that is out of spec. Also visually inspect all connectors, reseat them well. Try without the DVD player too. __________________ Begin Signature I fix TVs and electronics as a hobby and to save nice things from the dump. 40 LCD TVs, 4 monitors, 13 plasma TVs, and a 6.1 system! Free service manuals database: http://www.tgohome.com/ServiceManuals - Have a manual? Need a manual? Please PM me. I have successfully fixed (from best --> worst build quality): 3 Panasonic Plasmas, 1 Yamaha HTS, 1 NEC Plasma, 2 Sharp LCDs, 2 Toshiba LCDs, 5 Philips Plasma/LCD, 1 Hitachi Plasma, 5 LG LCD/Plasma, 10 Samsung LCD/Plasma, 1 Thomson Plasma, 1 Atec LCD, 1 Hanspree LCD, 1 Xerox LCD, 1 Harwa LCD, 2 Proview LCD, 2 Hyundai LCD, 1 "Onn" LCD, 1 Dell LCD, 1 iiyama LCD, 1 Logik LCD, 5 Bush LCD, 9 Vestel LCDs [Please do not PM me for help: I am a busy student, and we prefer input from all sides on this forum.]

08-06-2012, 11:58 AM	#26
Senatov Member Join Date: Aug 2012 City & State: Boston, MA My Country: USA I'm a: Knowledge Seeker Posts: 50	Re: Toshiba TV not powering on? Yes it is an LCD. The output from the PSU appears pretty constant. I don't think that any of the connectors could have become loose, as the TV sat on the cabinet all this time. The one thing that is kind of inconsistent is the clicking noise. When I plug it in, there is a click. When I press power, there are 2 clicks, when I press it again, there is one more click, and when I unplug it, there is a click. This clicking never happened when the TV was working. I would have heard it as the clicking is very loud.

08-06-2012, 11:59 AM	#27
ben7 Badcaps Veteran Join Date: Jan 2011 City & State: Trenton, NJ My Country: USA Line Voltage: 240v-120v 60Hz 200A service drop I'm a: Knowledge Seeker Posts: 1,959	Re: Toshiba TV not powering on? I would bet its one of the switching supplies on the board at the top, with the small heatsinks and small yellow transformers. Last edited by ben7; 08-06-2012 at 12:00 PM.. Reason: lol, spelling! //OCD

08-06-2012, 12:07 PM	#28
selldoor Slow Learner Join Date: Dec 2010 City & State: Lancashire UK Posts: 4,657	Re: Toshiba TV not powering on? Are you guys just forgetting the shorted PJ63 problem - mentioned earlier - there are a number of threads regarding this issue- the seine board is quite expensive to replace (if you can find one) and for a 7 year old set may not be economically viable.

08-06-2012, 12:23 PM	#36
Senatov Member Join Date: Aug 2012 City & State: Boston, MA My Country: USA I'm a: Knowledge Seeker Posts: 50	Re: Toshiba TV not powering on? Ok, I will try in a minute. I am actually working on my irrigation system at the moment. I am having a busy day off. Why do you think that the clicking did not happen when the TV worked?

08-06-2012, 12:28 PM	#37
multimeter Badcaps Veteran Join Date: Jan 2011 City & State: uk My Country: uk Line Voltage: 230v 50hz I'm a: Hobbyist Tech Posts: 352	Re: Toshiba TV not powering on? op,you said the caps were checked with a multimeter?analog? digital?,the only check you can do with a dmm,of analog meter is a kick test,and capacitance measurement,it wont confirm if the caps are high esr,are all the outputs stable?and at there correct voltages? __________________ fixed so far...376 lg lcd tv's,24 onn tv;s,24 panasonic lcd,16 jvc lcd,12 marshall jcm800 amps,refurb of various disco equipment lighting,old style disco decks ,and a flymo! ---------------------------------------------- please let us know if everything works ok if your tv gets fixed, as it will be and aid for anyone else having the same problem and wishing to fix it.it would save people clogging up this site with topics that are duplicated,and can be found easily using the search function.,and taking up valuable space.enjoy your fixed tv!,hopefully!

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