we have a custom board running Linux with a ADV7513. On the Linux side everything seems to work correctly: the driver is initializing and detects the display. But the display doesn't get a HDMI link (display says: no signal).
We don't have a adequate scope to measure the TMDS signals, but with our scope we get approx. 3V (what should be fine according to other forum entries) on all the lines.
We obsorved two strange things: the PLL is not locking and we have 0V at R_EXT pin. What could be the reason for that?
The audio part is not used and thus the input signals are connected to ground.
The relevant part of the schematic is attached...