Solved! Philips TV sound no picture

[philipsrich]

Trying to diagnose an issue with my Philips Ambilight TV (50PFT6510) that has recently decided not to display anything at all but I can hear sound and see the ambilights change etc.I have tried both HDMI ports and the antenna input from a few different sources (Laptop, Virgin media Tivo box etc), as well as having tried a few different HDMI cables. All to no avail and the TV still only plays sound but no image.

I have checked the power board and main board over for any blown capacitors but can’t see anything obvious. I have also replaced the TCON board and re-seated any ribbon cables to and from this board. Before this blank screen issue, we did have a dark strip on the TV that which indicated a row of LED’s on the backlight was not functioning.

At this point, i’m trying to work out if its worth diving deeper and spending some money on a replacement main board or just get a new TV???

If anyone has any suggestions, can see anything else I may have overlooked or has a pretty solid idea of what it might be i’d love to know.Thanks in advance,Rich

 

[ElectrO_90]

Can you shine a bright light on it while it is on, and see if this lights up the picture?
I'd say it was the back light.
Maybe you can disconnect it and put DC direct onto it and check if its working

 

[philipsrich]

I just read this as a process of elimination step elsewhere so I'll try this when i'm next with the TV (it's my parents) and report back. Depending on the outcome of that I should be able to work out if it's the backlight or the mainboard right?

 

[ElectrO_90]

Well the drivers for the LED could be gone, it could be one of the jungle chips not supplying to the drivers.
Could be all sorts of problems, and without a silly scope or manual, it's sort of guess work. But what I said should be relevant.

 

[philipsrich]

Perfect, thanks for your response... I'll look into the bright light method. If it's an LED driver that has given up the ghost, would you happen to know if that's a seperate board or if it's built into one of the others for that model.

 

[ElectrO_90]

It's been years since I played around with them.
Look on Ebay you'd be amazed what you can find if the LED's are dead.