Visio VL470M No Picture

[daniel5]

Re: Visio VL470M No Picture

Just for testing purpose, you can use 5A axial lead fuse, or car fuse for now

I should have a bussmann fuse laying around somewhere. I will try that this evening and see what happens. If that works, what would be the next step in testing?

[vinceroger69]

Re: Visio VL470M No Picture

im still trying to find a replacement fuse in a link for you what budm is suggesting is while your waiting for a fuse to come use a fuse you have if it doesnt blow your probably fine just to replace it if it does blow theres a short on your board somewhere and may have to order more parts or a replacement board.

[daniel5]

Re: Visio VL470M No Picture

Thanks vinceroger69 and BudM for all the help! It is greatly appreciated! I am prepared to order additional parts as necessary, treating this as one of my many learning projects.

[vinceroger69]

Re: Visio VL470M No Picture

some mainboards imo just cant be repaired economically or need special tools so even for the best engineers a board swap is some times needed.

[daniel5]

Re: Visio VL470M No Picture

Thanks, I will keep that in mind. ShopJimmy does not have my mainboard in stock. I will try the car fuse tonight and continue reading/watching youtube vids to see what else I can check to find a solution to the problem. This is my first tv electronic project and it has become very intriguing.

[vinceroger69]

Re: Visio VL470M No Picture

well untill you try the fuse you will never no it maybe a nice easy fix.

[daniel5]

Re: Visio VL470M No Picture

I soldered a 5a fuse to the faulty fuse and was able to get power to additional parts of the board(THANKS BUDM). I am getting correct voltage out of the powerboard. I checked all of the 3 pin regs and all seemed to have correct voltage with exception to the following:

U6
1117
pin 1 = 6.88
pin 2 = 8.14
pin 3 = 12.23

U4
1117
pin 1 = 0
pin 2 = 1.24
pin 3 = 3.31

TU4
1122
pin 1 = 0
pin 2 = 0
pin 3 = 0.13

U33 next to the main rail is a 4 pin(ea. side) the bottom side has 11.76/12.23/11.76/12.23 but the top has no voltage.

The sensor connector has (right to left) 1.20/5.13/0/0

I'm not getting any voltage from the main back to the inverter-on and the standby. So right now when I plug the tv in the vizio light on the front goes straight to white with no orange standby.

Anything standout to anyone?

[budm]

Re: Visio VL470M No Picture

So are you getting 24VDC at the inverter, and do you also get PS_ON, BL_ON signals?

[daniel5]

Re: Visio VL470M No Picture

No. In the attached pic, the only voltage I'm getting is about 1.76 on the 4th pin starting at the far left. That pin does not have a description.

[budm]

Re: Visio VL470M No Picture

Can you remove the connectors so I can see the labeling of each pin of the connectors? The wires are in the way.

[budm]

Re: Visio VL470M No Picture

BTW, what voltage do you get now on these two ICs that you were getting 0V before?:
U6
1117
pin 1 = 0.00
pin 2 = 0.00
pin 3 = 0.00
tab = 0.00

U8
7805CT
RAE947G
pin 1 = 0.00
pin 2 = 0.00
pin 3 = 0.00
tab = 0.00

[daniel5]

Re: Visio VL470M No Picture

U6
1117
pin 1 = 6.88
pin 2 = 8.14
pin 3 = 12.23

U8
7805CT
RAE947G
pin 1 = 5.01
pin 2 = 0.00
pin 3 = 12.23

[daniel5]

Re: Visio VL470M No Picture

Is there somewhere that I can download the schematics for my Vizio VL470M? How else do I determine the required voltages of the regulators?

[budm]

Re: Visio VL470M No Picture

"U6
1117
pin 1 = 6.88
pin 2 = 8.14
pin 3 = 12.23

U8
7805CT
RAE947G
pin 1 = 5.01
pin 2 = 0.00
pin 3 = 12.23"

They are OK.

[daniel5]

Re: Visio VL470M No Picture

Any ideas of what to test next?

[daniel5]

Re: Visio VL470M No Picture

Can you remove the connectors so I can see the labeling of each pin of the connectors? The wires are in the way.

sorry BudM, didn't see that post. Here is a new pic without the connectors.

[budm]

Re: Visio VL470M No Picture

OK, check the DC voltage on the ON/OFF (PS_ON), INV_ON (BL_ON: Backlights ON) using black probe on the chassis, red probe on the pin, check when TV is OFF and when TV is ON.

[daniel5]

Re: Visio VL470M No Picture

BudM, See attached image for the requested voltages.

[vinceroger69]

Re: Visio VL470M No Picture

have you tested this with or without the connector from the main board being in the socket?

[daniel5]

Re: Visio VL470M No Picture

ON = with connectors from mainboard in socket

OFF = without both connectors

The reason I tested without both connectors is that when I plug the tv in, it is not in standby mode.