Vizio VX37LHDTV10A

[budm]

Re: Vizio VX37LHDTV10A

That KHZ thing does not sound right with your meter. Try measuring a 9v batterires to see what you read. The circuit Ground in the primary side you are working on will be the negative leg of that large DC filter cap.

[tibimakai]

Re: Vizio VX37LHDTV10A

The big IC is a L6598D. Even Digikey has it.

[budm]

Re: Vizio VX37LHDTV10A

Check pin 12 the Vs pin to see if you have steady voltage there.
I also see 8-pin IC close by this L6598 IC. Do you have that number?
I also need the PFC IC number also since the same VCC will be used for the 12/24v Vcc for the smps IC.

[tibimakai]

Re: Vizio VX37LHDTV10A

on the one I have in my bedroom, I can't see anything. I will check tomorrow on the other two boards.

[tibimakai]

Re: Vizio VX37LHDTV10A

I have some numbers, but I'm not sure which one is the actual part number.
On the top is 103AIW
Second row is ST EK726

[tibimakai]

Re: Vizio VX37LHDTV10A

OK, I'm back with the original power supply which gives 5.1V for STBY and 13.3V for 12V and 26.6V for 24V without load. Do you notice that the 13.3V it's doubled for 24V? This measured from the connector's GND, not from the screw mount ground. From there I have 20.6V.
I guess something works OK in the power supply, since I'm getting the right ratio between the 12V and 24V. Something that takes the load it's blown, but what could be? Maybe a FET?
I need to get to the bottom of this power supply. I'm not even sure if only this is the problem with this TV, because before I touched it was showing the right voltages.
Budm I have put together the second PS and it shows exactly like the first one, just gives 4.9V and nothing else.

[tibimakai]

Re: Vizio VX37LHDTV10A

Budm, I need your help on this one, please
Today I have picked up a Vizio VO42L, replaced the slave inverter chip and it's ready for sale. Picked it up for $50, got the repair kit from China for $3.80.
Only the chip had to be replaced. I haven't done the fix.
I will have to look up that thread where it was specified which components needed for this fix. The print out it's not enough.

[budm]

Re: Vizio VX37LHDTV10A

Did you see the PDF of the mod? What did you get for the repair kit? When I fixed my, I replaced all 4 MOSFETs of both Master and Slave, 1 IC on the master that blown up, 4 caps (2 on each board). and I added mod fix to both boards.
So is the TV fixed and you just want add the mod to the boards?

[tibimakai]

Re: Vizio VX37LHDTV10A

The help is needed for the other Vizio, with the power supply.

I have just mentioned what I did today with the VO42L.
Do you really think that the caps need to be changed on the inverter boards?
I have replaced only the slave chip.

[budm]

Re: Vizio VX37LHDTV10A

I see, on the power supply. What happen when you install this one that you said it has all the out puts?

[tibimakai]

Re: Vizio VX37LHDTV10A

When I try with the bulbs, the 13.3V goes up like 20.6V(if I remember well because I haven't tested it since last time) and the 26.6V drops to 0V.
I will double check tomorrow.

[budm]

Re: Vizio VX37LHDTV10A

Try it in the TV, since it needs both ground pads on the board for grounding, make sure to use all the mounting screws, also try it without having the inverter boards connected.

[tibimakai]

Re: Vizio VX37LHDTV10A

You are sure, it sounds dangerous. I know that when connected a 12V bulb it would light up pretty bright(20V).

[budm]

Re: Vizio VX37LHDTV10A

But was it that the Ground for the lamps were not correctly used since the 24vdc power supply ground was not tied to the 5vstby and the 12v grounds?

[tibimakai]

Re: Vizio VX37LHDTV10A

Afternoon I will be re-checking everything again and I will be using the right grounds this time. I believe that the 12V it was from the screw, only the 24V has to be used from the connector.

[tibimakai]

Re: Vizio VX37LHDTV10A

I had some time and worked a bit on the PS.
I have replaced all the capacitors in the secondary and it's all OK!! Finally.
Tomorrow I will check the capacitors with my new ESR meter to see which one was bad.
By the way somebody has a chart about good/bad ESR values?
Now the next step is to see what else it's wrong with it?
Budm, I have tried it out with the bulb tester and they all worked well.
Not sure what went wrong the first time when I have tried out the bulb tester. Need to fix this one, to be able to buy a Hakko FX888.

[tibimakai]

Re: Vizio VX37LHDTV10A

Amber light turns white and in a couple of seconds goes back to amber.
In this time the voltmeter doesn't show 12V or 24V, but if I hook up the bulbs to the power supply they work well.
So it seems that the mainboard has a short? Both white fuses are OK.
Any ideas?

[budm]

Re: Vizio VX37LHDTV10A

Did you try disconnecting the cables to both inverters to see if the VIZIO Logo will stay white?
By the way, good to know that you got the power supply working, still do not understand what you did wrong before to get the strange output voltages.

[tibimakai]

Re: Vizio VX37LHDTV10A

I'm still puzzled too, but I'm glad that now it works.
The inverter, T-con are disconnected.

[budm]

Re: Vizio VX37LHDTV10A

Good, that eliminate the bad inverter board. Then you will have to start looking at the voltage regulators on the main board. Do you have the pictures so I can see if it is the same as my board?