Toshiba 47zv650u no power at all!!

**rmoody** · 08-08-2011, 08:55 AM

Re: Toshiba 47zv650u no power at all!!

C820 and c821 both read .004 volts. Getting nothing on them at all.

**PlainBill** · 08-08-2011, 11:45 AM

Re: Toshiba 47zv650u no power at all!!

Argh!!! Working two different power supplies and getting confused!!!

The bridge rectifier is on the heat sink labeled D820A. AC voltage is applied to the two center leads; DC voltage comes out of the two outer leads. What are the AC and DC voltages?

If both AC and DC voltages are present, I AM going to need a better picture of the bottom of the board.

PlainBill

**rmoody** · 08-08-2011, 01:23 PM

Re: Toshiba 47zv650u no power at all!!

D820A

started out @ .930 AC and slowly built up to over 1v kind of like the meter was charging it.

DC started out @ .630 DC and slowly started building.

**rmoody** · 08-08-2011, 01:30 PM

Re: Toshiba 47zv650u no power at all!!

got a glare on the pics but let me know if there's a more focuse area you would like a pic of.

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**rmoody** · 08-08-2011, 04:54 PM

Re: Toshiba 47zv650u no power at all!!

This would be much easier with a shematic or service manual. Have you searched for the power supply manual? it's PE0702. I can't really find anything on it either but thought you might could.

**PlainBill** · 08-08-2011, 09:40 PM

Re: Toshiba 47zv650u no power at all!!

Originally posted by rmoody

This would be much easier with a shematic or service manual. Have you searched for the power supply manual? it's PE0702. I can't really find anything on it either but thought you might could.

Yes, it would. I haven't been able to find anything.

Pardon me while I do a complete reset.

I've marked up the picture of the bottom, and I think I am getting closer. With the power supply connected to AC, measure the following points. All should be AC voltages. A1 to A2, B1 to B2, C1 to C2, D1 to D2, E1 to E2, and E1 to E3.

PlainBill

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**rmoody** · 08-08-2011, 10:42 PM

Re: Toshiba 47zv650u no power at all!!

Originally posted by PlainBill

Yes, it would. I haven't been able to find anything.

Pardon me while I do a complete reset.

I've marked up the picture of the bottom, and I think I am getting closer. With the power supply connected to AC, measure the following points. All should be AC voltages. A1 to A2, B1 to B2, C1 to C2, D1 to D2, E1 to E2, and E1 to E3.

PlainBill

a1-a2= 124v
b1-b2= 124b
c1-c2= 124v
d1-d2= 124v
e1-e2= 1.4vac and slow rising
e1-e3= 124v

**PlainBill** · 08-09-2011, 06:20 AM

Re: Toshiba 47zv650u no power at all!!

Originally posted by rmoody

a1-a2= 124v
b1-b2= 124b
c1-c2= 124v
d1-d2= 124v
e1-e2= 1.4vac and slow rising
e1-e3= 124v

OK, and now to figure out why. I'm going to need a better picture of the area outlined in white in the attached picture. If at all possible, take the picture in a well lit area.

If you look at the corresponding area on the top of the board there are two relays. What are the part numbers of them?

PlainBill

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**rmoody** · 08-09-2011, 08:15 AM

Re: Toshiba 47zv650u no power at all!!

I was suspect of these relays in the beginning because the board had a lot of work done one it before with someone trying to get it working and I believe one of the relays had been replaced.

sr80= lkt1af-5v
sr81= Omron g5pa-1, can't read any more of this relay without taking out of circuit.

**rmoody** · 08-09-2011, 08:28 AM

Re: Toshiba 47zv650u no power at all!!

Here's the best pic I can get at the moment.

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**rmoody** · 08-09-2011, 09:13 AM

Re: Toshiba 47zv650u no power at all!!

OK Bill, Here's my situation on this. When I opened the back there was a bag of screws for the back panel and power board and it also had one of these relays in it. Here's how i found it:
sr80= Omron 5Vdc
sr81= Lkt1af-5V dc
The relay in the bag that had been pulled is another Omron but it's a 12V. My thinking is He maybe put the wrong relay and possible even switched up which one is supposed to be a 5V and which is supposed to be a 12v. Any way to figure that one out?

**rmoody** · 08-09-2011, 09:16 AM

Re: Toshiba 47zv650u no power at all!!

Oh and i tried checking resistance on the 3 relays and the 2 5V relays were 100 & 103 Mohms. The 12V is .270 Kohms which makes me believe it may be the bad one. Which was pulled when I got the TV

**PlainBill** · 08-09-2011, 01:22 PM

Re: Toshiba 47zv650u no power at all!!

Those pictures clear thing up. What is the information (value) printed on R850? And with the power disconnected, what resistance do you get?

PlainBill

**rmoody** · 08-09-2011, 01:31 PM

Re: Toshiba 47zv650u no power at all!!

Originally posted by PlainBill

Those pictures clear thing up. What is the information (value) printed on R850? And with the power disconnected, what resistance do you get?

PlainBill

R850 reads up to 17 Mohms and then starts falling off lower.
Its labeled
RGDU5M-5E
1.8 OHMS J
NOBLE 98

**rmoody** · 08-09-2011, 02:33 PM

Re: Toshiba 47zv650u no power at all!!

Just a little FYI, I pulled the caps off of the relays and neither of them are closing when power is applied. So i set my meter on the connectors for main and inverter board and I activated the relay and when I did, I immediately got 12Vdc. My problem seems to be lying right here close to these relays. Maybe that resistor I tested earlier. That sounds High to me.

**rmoody** · 08-10-2011, 06:21 PM

Re: Toshiba 47zv650u no power at all!!

OK Bill, I ended up finding a power board shipped to my door for $50. I compared some of the values from the good board and that resistor you had me check is definitely bad. Anyways on to the next thing. I got the board in and now it powers on and displays for a few seconds but I'm getting a buzz from the inverter boards. Seems like master and slave have the same sound. I recorded a video and posted to photobucket if you would like to watch it and see what it's doing. After it buzzes a few seconds It shuts down and gives 2 series of 3 flashing orange lights. The inverters shut down after just a few seconds.

http://s1005.photobucket.com/albums/...urrent=011.mp4

**PlainBill** · 08-10-2011, 08:48 PM

Re: Toshiba 47zv650u no power at all!!

Yes, that resistor was definitely bad. It bypassed the contacts of the relay to provide standby power which would turn the relay on. Replace it and you will have a spare power supply.

I think you uploaded the wrong video.

You know the drill - pictures of the inverters.

PlainBill

**rmoody** · 08-10-2011, 08:54 PM

Re: Toshiba 47zv650u no power at all!!

Originally posted by PlainBill

Yes, that resistor was definitely bad. It bypassed the contacts of the relay to provide standby power which would turn the relay on. Replace it and you will have a spare power supply.

I think you uploaded the wrong video.

You know the drill - pictures of the inverters.

PlainBill

Will get some pics of the inverters. Its very weird to me that both could be bad. Could this be caused by something bad on the new power supply? it has 24 volts at the connector. Main inverter is under the main so I will have to remove it again for a pic. Could this be from maybe a lightning strike or power surge? The video was just so you could hear the buzzing and see the backlights turning on and back off.

**PlainBill** · 08-10-2011, 09:07 PM

Re: Toshiba 47zv650u no power at all!!

Originally posted by rmoody

Will get some pics of the inverters. Its very weird to me that both could be bad. Could this be caused by something bad on the new power supply? it has 24 volts at the connector. Main inverter is under the main so I will have to remove it again for a pic. Could this be from maybe a lightning strike or power surge? The video was just so you could hear the buzzing and see the backlights turning on and back off.

A Power surge / lightning strike can cause damage at multiple points. You have indicated you obtained the TV in a non-working condition. There is a long tradition of less than ethical 'technicians' (to use the term very loosely) jamming a number of bad parts into a TV and selling it as 'It just quit'.

PlainBill

**rmoody** · 08-10-2011, 09:12 PM

Re: Toshiba 47zv650u no power at all!!

Got the tv to quit buzzing for a short time but it started after 10-20 seconds and eventually shut the unit down again. Here's some pics. One of the slave had quite a glare.

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