Sony kdl-60r520a backlight no video

[microvibe]

Sony kdl-60r520a

It turns on backlight comes on bright then dims alittle. Press input on remote green light flashes like it acknowledges the selection but no video or sounds tried different inputs.
Power supply output voltages right on spec. Tested Tcon transistor for short that is common to this tv but it's good . Fuse is good. I read thru 70" Visio thread thought might be able to remove side tab driver board ribo cable see if was side tab driver issue but this tv just has tabsmouted to panel no board on side.
Because no sound possibly main board or still could be Tcon. There are Tcon repair kits have transistor and driver ic how do I test driver ic?

[dskall]

Re: Sony kdl-60r520a backlight no video

Any effect if you remove one ribbon cable at a time?

[microvibe]

Re: Sony kdl-60r520a backlight no video

Nope nothing just backlight that's it's.doesnt go white or black

[dick_barton]

Re: Sony kdl-60r520a backlight no video

5A fuse OK on the Tcon?

[microvibe]

Re: Sony kdl-60r520a backlight no video

Ya I have voltage on both sides of fuse.

[budwich]

Re: Sony kdl-60r520a backlight no video

the side tabs are still connected to the bottom edge boards with a detachable connector at the corner. that is where you need to disconnect to see if you get a picture and then go from there. Make sure you are actually inputting something or at least selecting menu.

[dick_barton]

Re: Sony kdl-60r520a backlight no video

I see that it has a Sharp Tcon board and know that there have been quite a few threads about them failing. I'm sure that a search of the forum will bring up some information

[dskall]

Re: Sony kdl-60r520a backlight no video

Blurry picture but if you can find test points.

T-con voltages (typical)
1. Vin (Vcc): 12Vdc or 5Vdc
2. Vdd (Vlogic, Vddd): 3.3Vdc
3. Vda (Vs, Vsource, Vdda,Avdd): 14Vdc~20Vdc
4. Vgh (Vgon, Von, Vddg): 20Vdc~30Vdc
5. Vgl (Vgoff, Voff, Veeg): -5Vdc~-7Vdc

[microvibe]

Re: Sony kdl-60r520a backlight no video

I can't find side boards I took met strip off ass well see tabs that's it no connectors on bottom corners. The reason I ask about mainboard is because no sound

[budwich]

Re: Sony kdl-60r520a backlight no video

there aren't any side boards... but the side tabs are connected down to the bottom edge boards at the corners. Anyways, hopefully your "meter investigations" will lead somewhere.

[microvibe]

Re: Sony kdl-60r520a backlight no video

I can't find any Tcon test points debating on ordering one but since no sound maybe need main board . Because doesn't have side tab boards if one those tabs are burnt out would that cause this too? Don't want dump money intonit if bad panel .

[microvibe]

Re: Sony kdl-60r520a backlight no video

Well I'd took apart panel TV found one burnt chip on one of the tabs on the side so I removed that side tab drivers turn the TV on that's just a pure white screen as if the t-con is disconnected I tested the part in the shopjimmy video on this t-con you're supposed to have 15 volts coming out of transistor I think it is and I got three and a half volts when I test resistance it doesn't test short wondering if there's more wrong on the t-con than just the common part that goes

[freakaftr8]

Re: Sony kdl-60r520a backlight no video

Disconnect LCD panel from tcon and measure your 15v and see if it comes back

[microvibe]

Re: Sony kdl-60r520a backlight no video

15v doesn't come back with panel disconnected

[freakaftr8]

Re: Sony kdl-60r520a backlight no video

Obviously ic301 is not being powered up for some reason. Check all inductor coils around ic301 for any power. Should have 3.3, 5, 17 or so Vdc