Sony KLV-46W400A Power Ok, Blank Screen. How to test T-Con board?

[nobbnobb1]

Hello,

I have a Sony KLV-46W400A that powers on but has a blank screen. Backlight is lit. I am unable to find any service manual for this TV, but this looks like a symptom of a bad T-Con board. The T-Con board is a FS_HBC2LV2.4 and has various test points on it.

Does anyone have any reference material on how to best test this T-Con board? I started with the fuse and that tested ok.

Suggestions appreciated. Thanks!

EDIT:
I found this post where a user created a T-Con board check spreadsheet: https://www.badcaps.net/forum/showthread.php?t=35301

All voltages on my power supply tested ok. I am getting 15.1 volts on VMGA #1-9, but 0 volts on VMGA #10 - 18. I'm guessing this means my T-Con board is bad? Attached is the filled in spreadsheet.

Is there a way to also test the main board?

[budm]

Re: Sony KLV-46W400A Power Ok, Blank Screen. How to test T-Con board?

We need good clear starlight shots of the T-CON board so we can see test points.
Look for test points VGH, VGL, AVDD, etc.

[nobbnobb1]

Re: Sony KLV-46W400A Power Ok, Blank Screen. How to test T-Con board?

Thanks! Attached is a picture of the T-con board and the various points I tested. Results are:

IN: 11.8
VIN: 11.9
AVDD: 15.2
AVDD_1: 15.2
TCON_RDY0: 3.3
F_VCOM_R: 6.4
VCOM_D: 10.9
VCOMG2L: 6.4
VCOMG1: 6.2
VON: 20.8
VOFF: -7.5
VMGA1: 15.1
VMGA2: 15.1
VMGA3: 15.1
VMGA4: 15.1
VMGA5: 15.1
VMGA6: 15.1
VMGA7: 15.1
VMGA8: 15.1
VMGA9: 15.1
VMGA10: 0
VMGA11: 0
VMGA12: 0
VMGA13: 0
VMGA14: 0
VMGA15: 0
VMGA16: 0
VMGA17: 0
VMGA18: 0

[petehall347]

Re: Sony KLV-46W400A Power Ok, Blank Screen. How to test T-Con board?

check voltage both sides of fp1 . i have had fuses test good and be bad .

[budm]

Re: Sony KLV-46W400A Power Ok, Blank Screen. How to test T-Con board?

What is the P/N of that TFT Bias power supply IC10 (IC1D?) on the left section of the board?
VCC_3.3 = ????
VDD = ????

[nobbnobb1]

Re: Sony KLV-46W400A Power Ok, Blank Screen. How to test T-Con board?

check voltage both sides of fp1 . i have had fuses test good and be bad .

11.8V and 11.8V on both sides. Fuse is good.

[nobbnobb1]

Re: Sony KLV-46W400A Power Ok, Blank Screen. How to test T-Con board?

What is the P/N of that TFT Bias power supply IC10 (IC1D?) on the left section of the board?
VCC_3.3 = ????
VDD = ????

IC10 has the following etchings:
ISL976
50ARTZ
F826XHZ

VCC_3.3 = 3.3V
VDD = 3.3V

What are you checking for in this case (just curious)?

[budm]

Re: Sony KLV-46W400A Power Ok, Blank Screen. How to test T-Con board?

Need to locate VGL, VGH.

[nobbnobb1]

Re: Sony KLV-46W400A Power Ok, Blank Screen. How to test T-Con board?

Need to locate VGL, VGH.

I just looked, does not exist on the T-con board

[budm]

Re: Sony KLV-46W400A Power Ok, Blank Screen. How to test T-Con board?

ISL97650b
OK, VOFF, VON look to be OK.
So far the GAMMA reference Voltage are bad, try checking GAMMA Voltages again without having cables between T-CON and the panel connected. Notes: TV may not startup if this TC has detection for faulty T-CON.
May be time for new T-CON board.

[nobbnobb1]

Re: Sony KLV-46W400A Power Ok, Blank Screen. How to test T-Con board?

Thanks, I ended up ordering a new FS_HBC2LV2.4 T-Con board. They are going for only $6 USD on Aliexpress and the seller has 500 of these...wow! The seller only has a generic picture up, but if they have so many of these for sale maybe they are new units.

I'll swap the board in when I get it and report back.

[nobbnobb1]

Re: Sony KLV-46W400A Power Ok, Blank Screen. How to test T-Con board?

As an update, it seems many of these Chinese FS-HBC2LV2.4 T-con boards are missing an IC (P2042AF) which may be why they are going for so cheap. These sellers have thousands in stock so my guess is this is a bad batch that was improperly manufactured. Going to buy a separate P2042AF to solder on and see how that works.

[Diah]

Re: Sony KLV-46W400A Power Ok, Blank Screen. How to test T-Con board?

why you want to solder this IC if the boards design not included... its reducers of electromagnetic interference.. its not most in boards ... did your set handle 3D or high frequencies ??

[nobbnobb1]

Re: Sony KLV-46W400A Power Ok, Blank Screen. How to test T-Con board?

why you want to solder this IC if the boards design not included... its reducers of electromagnetic interference.. its not most in boards ... did your set handle 3D or high frequencies ??

I don't think this set has 3D features but the OEM board that I am replacing has this IC so I figure it should be there? I haven't received the replacement board yet to test but I suppose I could always desolder the existing IC and move it to the new board. I just find it weird that all these Chinese sellers are selling these IC-less boards for <$10 so it must be a bad batch where the manufacturer messed up on not soldering on the IC.

[nomoresonys]

Re: Sony KLV-46W400A Power Ok, Blank Screen. How to test T-Con board?

This one doesn't seem to have that either: https://www.ebay.com/itm/LJ94-02217H...oAAOSwz1Rci~J5

[nobbnobb1]

Re: Sony KLV-46W400A Power Ok, Blank Screen. How to test T-Con board?

This one doesn't seem to have that either: https://www.ebay.com/itm/LJ94-02217H...oAAOSwz1Rci~J5

Interesting. Seller says that one comes from a broken screen. So maybe for this T-con board that IC isn't necessary.

[Diah]

Re: Sony KLV-46W400A Power Ok, Blank Screen. How to test T-Con board?

I don't think this set has 3D features but the OEM board that I am replacing has this IC so I figure it should be there? I haven't received the replacement board yet to test but I suppose I could always desolder the existing IC and move it to the new board. I just find it weird that all these Chinese sellers are selling these IC-less boards for <$10 so it must be a bad batch where the manufacturer messed up on not soldering on the IC.

not any cheap are bad and not any expensive are good...
as i wrote before its not most in boards.. i think your T-CON installed with metal shield cover.. if so then the shield enough to reduce the electromagnetic field freq.

[budm]

Re: Sony KLV-46W400A Power Ok, Blank Screen. How to test T-Con board?

Did you match the PCBA numbers as printed on the barcode sticker?
FS-HBC2LV2.4 is the blank PCB number which can be stuffed to make many difference PCBA's.

[nobbnobb1]

Re: Sony KLV-46W400A Power Ok, Blank Screen. How to test T-Con board?

Did you match the PCBA numbers as printed on the barcode sticker?
FS-HBC2LV2.4 is the blank PCB number which can be stuffed to make many difference PCBA's.

As per the original image of the T-Con board, the only barcoded number I see is "k2204k8h0d2r016947" which turns up nothing in Google. All the generic images for the FS-HBC2LV2.4 that are being sold look like mine, with the exception of the missing IC so I figure it should be a drop in replacement.

[budm]

Re: Sony KLV-46W400A Power Ok, Blank Screen. How to test T-Con board?

It will not be just missing the IC, supported parts, I.E. caps, resistors, etc probably not installed either. And possibly FW also.