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Old 03-29-2012, 11:40 PM   #41
tibimakai
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Default Re: Vizio VX37LHDTV10A

I'm using for ground the corner mounting screw hole, that could make a difference? I think that here I have messed up.
You are using the GND from the connectors and I have a common ground for all bulbs and using the mounting hole ground.
I have just measured with an ohm meter and they are not the same.
What is the wattage of your bulbs?
For 3.3V I can use a bench top power supply? The ground has to be the GND from the connector?
I will remake my bulb tester and I will take new measurements. I will be back most likely tomorrow.
Your PS looks different then mine.
Now if I could fix the pop in the Toshiba. I have three more TVs waiting on me. Five TVs in total.
Right now the PS is out of the TV, I will let you know tomorrow what it does the Vizio logo.
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Old 03-29-2012, 11:53 PM   #42
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Default Re: Vizio VX37LHDTV10A

The mounting holes (on my power supply) by the connectors are connected to all the ground pins, you can see the jumpers, of the output connectors, so that should not be the problem. I use 1157 bulbs, I think the low filament is about 8watts and the HI filament is about 26watts. I use the low filaments. http://www.run-n-lites.com/bulbspec.asp
You sure pick the hard stuff to work on with a lot of strange problems, but that is how you learn and you will never forget them again.
How far are you from me to San Francisco bay area?
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Old 03-30-2012, 12:25 AM   #43
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Default Re: Vizio VX37LHDTV10A

I'm in LA. I was in SF on 4th of July.
But if I measure the grounds with the multimeter it won't beep at the 12v and 24v connectors, only at the 5v.
I use 4.4W/7V bulb and 12.2W/12V bulbs, none of them has high beam.
I have purchased mini hooks(red and black) and I will install them tomorrow for the GRD too and I will be using the connector GRD.
It's possible that I have blew four power supplies? I don't really see what I have done wrong.
I have these two hard ones, but I have picked up some very easy ones too.
I've got a 40" Sony/1080P/120HZ/Smart TV for $80 and the only thing I did is to reset it and installed the latest firmware.
I have a 46" Samsung 1080P "the picture went out", paid $130, but I can't find the problem because it's working great.
I had a Sharp where I had to tighten the screws on the inverter board.
Some capacitor replacements, Y buffer boards, so it was pretty easy up until now.
I still have a 42" Sharp 1080P which has a low PS-ON, but has all the voltages?! This one a bit later.
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Old 03-30-2012, 12:37 AM   #44
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Default Re: Vizio VX37LHDTV10A

"But if I measure the grounds with the multimeter it won't beep at the 12v GND and 24vGND connectors" so the GND labELS on the connectors are not connected to each other at all?

Those bulbs are fine, so it sounds like you need the correct ground points for you lamp, which should be the negative legs of the 12vdc filter caps or the 24vdc filter cap negative legs, the 12vdc filter cap neagtive legs should be connected to the negative legs of the 24vdc filter caps, it is really strange that only 5v negative legs of the filter caps are connected to the mounting holes.
I look at the pictures of your power supply connectors, they are arranged and labeled just like mine.
Can I see the bottom side of the connectors so I can see how they are hooked up?

Last edited by budm; 03-30-2012 at 12:40 AM..
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Old 03-30-2012, 01:10 AM   #45
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Default Re: Vizio VX37LHDTV10A

Both of yall should have a lot of broken sets to choose from being in such big cities. Granted everyone ive known from LA is like scared to drive out of their sub city, like say to go from ontario to burbank. Im working on around 5 items right now, but usually im lucky to find one a month. I think plain bill lives near me, im tempted to show up with 5 lcd's at his lab.
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Old 03-30-2012, 01:22 AM   #46
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Default Re: Vizio VX37LHDTV10A

I'm working on 5 TVs right now as well. I drive even 70 miles if I see a good TV or I can pick up two at ones.
I'm. even thinking to get a minivan to be able to pick up bigger TVs.
I have started this in February.
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Old 03-30-2012, 01:25 AM   #47
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Default Re: Vizio VX37LHDTV10A

I get to see hundreds of monitors, TVs, laptops, desk tops, electronics equipments of all sorts every week since I do the volunteer work once a week at www.crc.org, and I get free lunch!. If it uses electricity, I will work on it, keeping stuff off the landfill and help out the poor around the world at the same time, been doing it for 15 years so far, otherwise I am real busy at my regular job.
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Old 03-30-2012, 01:50 AM   #48
tibimakai
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Default Re: Vizio VX37LHDTV10A

Since February I have fixed/sold eight TVs, I have kept two for myself I have one for sale right now and I have five in my garage, one of them it's working which should have no picture.
I see another 42" Vizio 1080P, 3 HDMI, and I have to let it go, because I don't have room and time to work on. Most likely the chip and fets have to be changed on the slave inverter (VO42L).
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Old 03-30-2012, 01:56 AM   #49
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Default Re: Vizio VX37LHDTV10A

You mean this Vizio that you have to replace the blown IC and MOSFETs and modify the boards with 2 resistors, caps, 33V TVS?
http://s807.photobucket.com/albums/y...VO42LFHDTV10A/
Been there, done that.
Attached Files
File Type: pdf LG_inverter_modification_II_v1.2.pdf (630.2 KB, 12 views)
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Old 03-30-2012, 02:01 AM   #50
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Default Re: Vizio VX37LHDTV10A

yes, that one. I'm almost sure that it has this issue.
budm, no pointers on the Toshiba's pop? That one too, it was working, I didn't have to do anything, but just to be sure, that I won't have surprises I have replaced the capacitors, but this popping is killing me. I can't sell it this way.
So basically 16 TVs in two months, not bad.
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Old 03-30-2012, 02:10 AM   #51
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Default Re: Vizio VX37LHDTV10A

I have to do some thinking about that one to find out what is causing the pops on both channel. You may need to use the scope for probing it since your meter is not sensitive enough to use. I am thinking about using small audio amplifier (Powered PC SPEAKER), using a small .1uf cap 25v or so attach one end to the amplifier input, the ground of the amplifier to the chassis, and use the other end of the cap for probing for the popping noise, it may work as a cheap probe. You have to use shielded audio cable for the amplifier input wire. Or you can shot gun by changing the caps around that IC, you may also have bad IC.
I use to use this for probing the amplifier to find out which stage of the audio circuits stop working, they use to sell this audio probe for audio repair, but I am too cheap to ever buy one.

Last edited by budm; 03-30-2012 at 02:14 AM..
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Old 03-30-2012, 02:20 AM   #52
tibimakai
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Default Re: Vizio VX37LHDTV10A

I would buy a cheap scope, but I don't know anything about how they work, how to use them.
There are some small pocket scopes if I remember well they are 1MHZ scopes, and I'm not sure if it's good for TV repair or not.
http://www.seeedstudio.com/depot/dso-nano-v2-p-681.html
I'm even thinking of installing a small amplifier in the TV to replace the original one.
So if I'm using the RCA output and I don't hear anything, then it's 100% that my problem is in the amlifier area. It could be a SMD capacitor or the chip itself? The electrolytic caps were replaced already.
Here it is, it's cheap but not easy to replace:
http://search.digikey.com/us/en/prod...3-1-ND/1014220

Last edited by tibimakai; 03-30-2012 at 02:30 AM..
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Old 03-30-2012, 07:49 AM   #53
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Default Re: Vizio VX37LHDTV10A

Quote:
Originally Posted by cashkennedy View Post
I think plain bill lives near me, im tempted to show up with 5 lcd's at his lab.
PlainBill has been MIA for almost a month now, but unless he has moved recently, he is in Phoenix AZ.
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Old 03-30-2012, 09:21 AM   #54
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Default Re: Vizio VX37LHDTV10A

Oh thats right, i thought he lived in dallas till you reminded me.
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Old 03-30-2012, 10:09 AM   #55
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Default Re: Vizio VX37LHDTV10A

TV has what is call Pre-amp, which amplifies the small audio signals (in milivolt) from the tuner or from the inputs and then it will go to volume control, equalizers, etc. this signal is ampilfied enough to about 1V (0dBV) and sent to the RCA audio output that is strong enough to drive the input circuits (light load) of the external amp input circuits (usually about 47K input impedance), this same signal is also sent to the power amplifier which can drive the heavy load impedance of 4~32 Ohms.

Last edited by budm; 03-30-2012 at 11:12 AM..
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Old 03-30-2012, 11:21 AM   #56
tibimakai
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Default Re: Vizio VX37LHDTV10A

The person that I have purchased the TV from said that the TV would not turn on sometimes. Do you think that this popping can do that?
I haven't noticed this startup issue yet. Maybe the amp chip shorts out sometimes?
Maybe we should write about this in the Toshiba(Atlas) thread.
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Old 03-30-2012, 07:25 PM   #57
tibimakai
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Default Re: Vizio VX37LHDTV10A

budm, let's return here the discussion about this TV.
The pictures from the bottom of the power supply are at the post #13.
It looks like there are some jumpers going from the chasy screw ground to the 5v and 12v, but I can't see one for the 24v. I have to look at the board itself.
I will re-make the bulb tester to match yours, just to be sure and I will use a 1K resistor to start the PS. I won't use the bench top PS.
You are not using a bulb for the 5v? I guess it's not really necessary.
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Old 03-30-2012, 08:16 PM   #58
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Default Re: Vizio VX37LHDTV10A

No need for the 5vdc. I will hook up the lamp to the ground terminal for each supply connectors. 24vgbd for 24v lamp gnd. 12vgnd for 12v lamp gnd.
I look at your pictures and see what is going on with the 24vdc gnd, it is tied to the mounting hole close to the 24 VDC opposited the other mounting hole GND, so when you mount the board into the chassis, all the cold side ground will be tied together through the chassis, this not very good way since if the mounting screws are loose then you can have bad ground which can easily happen.

Last edited by budm; 03-30-2012 at 08:21 PM..
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Old 03-30-2012, 08:28 PM   #59
tibimakai
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Default Re: Vizio VX37LHDTV10A

so it can't be tested outside. It's possible that this caused to blow the PS?
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Old 03-30-2012, 09:58 PM   #60
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Default Re: Vizio VX37LHDTV10A

Yes you can still test it outside the TV, just make sure to use the 24v GND terminal for the 24v lamp ground.
The way you had it hookup before should not damage the PS. If you think about it as having 3 batteries, one 6V (5V) batteries, one 12v batteries, and one 24v batteries. The 6v and the 12v batteries negatives are tied together (just like your TV), but the negative of the 24v batteries is not connected, so when you have the 24v lamp one end connected to the 24v Plus terminal and the other end is connected to the 6v/12v terminal, the circuit for the 24v then will not be completed, the 24v lamp will not light up.
So hook up the lamps and use the ground of each supply for each lamp ground return, then your lamps should light up, no need to hook up the lamp to the 5V standby.
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