Phillips 42PFL3704D/F7 Inverted Picture

[dan88]

I have a Phillips 42PFL3704D/F7 with an inverted picture. What I mean by that is that it is upside down and backwards. If I mounted the TV upside down and watched it in a mirror, the picture would seem right. There are no problems with brightness, contrast, or sharpness. It's just inverted.

I've tried the following:
1) I upgraded to the latest firmware.
2) I looked through all the settings on the menu, but nothing made any difference.
3) I looked at the power board, inverter board, and main board for any blown components. Nothing looks blown. I did not actually test any of the components.

There is no reset option in the menus. The only reset is to leave it unplugged for 30 seconds, but that has no affect either.

What can I try next?

Thank you in advance for your help!

Dan

[dan88]

Re: Phillips 42PFL3704D/F7 Inverted Picture

Here's a few pictures to help. After getting the picture of the Zelda game on the computer, I determined that the picture is flipped along the horizontal axis.

[budm]

Re: Phillips 42PFL3704D/F7 Inverted Picture

Did it just happen one day just like that? Very strange problem indeed.

[RON_CET]

Re: Phillips 42PFL3704D/F7 Inverted Picture

This type symptom is a gate driver failure in panel, V420H1-L13 REV C1 Chi Mei Optoelectronics number of panel appears be most common of this failure

[tom66]

Re: Phillips 42PFL3704D/F7 Inverted Picture

The gate driver actually fails and this causes this problem? Very strange!

[budm]

Re: Phillips 42PFL3704D/F7 Inverted Picture

That is strange if the gate drive fail you will not get good pictures, it has good pictures but inverted.

[tom66]

Re: Phillips 42PFL3704D/F7 Inverted Picture

Perhaps there's a control line which decides which way up the picture should be and this goes awry. I can't see of any reason for that, though.

[budm]

Re: Phillips 42PFL3704D/F7 Inverted Picture

If we can get the LCD panel spec, it will tell us the pinout of the T-CON board.
See example in PDF.

[RON_CET]

Re: Phillips 42PFL3704D/F7 Inverted Picture

Here's a service bulletin for that model to make sure you have updated the correct firmware,since there few different version of that model,also we have seen this model come in for issues of customer indicating no HDMI inputs working and upon changing main digital board we have also seen the inverted
picture occur after install of new digital main,but after updating firmware on new board this would correct the inverted issue,however we have seen some of these models that did come in during warranty period with inverted picture,that panel replacement corrected also.

[dan88]

Re: Phillips 42PFL3704D/F7 Inverted Picture

Let me see...

I have no idea how it happened. I got it at a yard sale for $20. I'm hoping I can fix it for less than the cost of getting a new TV.

If it is the panel, does that mean I'd have to replace the whole panel? I understand that's the most expensive part.

My TV was manufactured in August of 2009, so it is outside the scope of the service bulletin you referenced. One of the first things I tried was upgrading to the most current firmware (1.6). Too bad it wasn't that simple.

I'll see if I can find a panel spec similar to the one budm referenced.

Also, there is one other board I haven't looked at yet, because the disassembly required to get to it would take more time than I've had available this week. You can just see the edge of it in the attached photo. I'm hoping to get to it Saturday. There may be a blown component on that board.

Thank you for all your help!!

Dan

[dan88]

Re: Phillips 42PFL3704D/F7 Inverted Picture

I may have found the problem. Remember the board from the previous post that I could only see its edge? I found a transistor that tests bad. It's labeled D9 on the board, and when I tested it like a transistor, it failed. Current can flow in all directions. There is an identical part labeled D10 just to the right and lower than D9. It tests like a good NPN transistor.

Now for the bad news. This are really tiny SMD components. It's beyond my skill set to solder something that small. The second piece of good news is that I can't find the board (HA727V 151C1) for sale anywhere when I google it.

Any suggestions?

[tom66]

Re: Phillips 42PFL3704D/F7 Inverted Picture

It would be very surprising to me if that diode failed and caused this problem, but it's worth a shot -- it does provide VGL which is used by the gate drivers.

[tw2005]

Re: Phillips 42PFL3704D/F7 Inverted Picture

Have a go, if you have 2 irons you should be able to get it off cleanly. A magnifier will help. Here's the datasheet for the pins so you can test them as diodes!

[tw2005]

Re: Phillips 42PFL3704D/F7 Inverted Picture

what panel number do you have?

LC420WUN-SBA1

http://www.shopjimmy.com/lg-philips-...-con-board.htm

http://www.ebay.com.au/itm/PHILLIPS-...item2c6e33d938

http://www.ebay.com.au/itm/LG-Philip...item589f0192f8

edit: datasheet removed was for WUD not WUN.

[mike72]

Re: Phillips 42PFL3704D/F7 Inverted Picture

I may have found the problem. Remember the board from the previous post that I could only see its edge? I found a transistor that tests bad. It's labeled D9 on the board, and when I tested it like a transistor, it failed. Current can flow in all directions. There is an identical part labeled D10 just to the right and lower than D9. It tests like a good NPN transistor.

Now for the bad news. This are really tiny SMD components. It's beyond my skill set to solder something that small. The second piece of good news is that I can't find the board (HA727V 151C1) for sale anywhere when I google it.

Any suggestions?

Were you able to repair your tv as I have one Exactly the same