37LG710H (CHASSIS:LA95A) - LG TV Service Manual (repair manual). Page 45

Check TU100 Pin16(Video output)
Can you see the normal signal?

Check the input(Pin1) of LPF(IC100).
Can you see the normal waveform?

YES

NO

Could you measure voltage of TU100 & IIC lines?
Are they all normal?

Check the output(pin17) of IC1500 
Can you see the normal waveform?

Check the input(PinAB11) of BCM3549(IC100).
Measure waveform at C1109 because it’s more easy to check.
Can you see the normal waveform?

NO

You should check power line 
& IIC lines.

YES

You should replace TUNER.

NO

After checking video signal line & the Power of LPF you should decide to replace item or not.

NO

After checking the Power/IIC of  IC1501, you should decide to replace it or not

YES

This board has big problem because Main chip(BCM3549) have some troubles.
After checking thoroughly all path once again, You should decide to replace BCM3549 or not.

YES

YES