A: Vestel released revisions. Look for the "REV" number on your board. A Rev 1.0 schematic may not match a Rev 3.0 board exactly. You may need to search for "17IPS12 Rev 3.0 schematic".
The TV turns on, the standby light goes steady, you can hear audio, but the screen remains completely black. If you shine a flashlight closely at the screen, you can see a faint image. vestel 17ips12 schematic
If your output voltages are fluctuating or slightly too low/high, replace the optocoupler (usually a PC817 variant) and the TL431 voltage reference chip to stabilize the regulation circuit. A: Vestel released revisions
Locate the secondary output pins going to the mainboard. Measure for the stable 12V and 5V rails. If these voltages are fluctuating rapidly, suspect a shorted secondary diode or a faulty feedback optocoupler circuit. You may need to search for "17IPS12 Rev 3
Connect your voltmeter to the LED output pins and turn on the TV. If the voltage spikes up high (e.g., over 100V) and then drops instantly to a lower resting voltage (like 12V or 24V), the driver board is working fine. The open-circuit protection is triggering because an LED strip inside the panel has burnt out. 4. Tips for a Successful 17IPS12 Repair
LED driver boost MOSFET and output capacitors.
Stepping up or regulating the DC voltage to drive the internal LED backlight strips.