Measure voltage at LED output connector during power-on. If it spikes high and drops, a panel LED is open. If no spike, the boost MOSFET or driver IC is dead. Overheating or weak startup circuit.
: Offers a free download of the service manual and circuit diagram. Scribd (17IPS72P/R4)
输入级包括：Fuse F100（T3.15A慢熔保险丝）、MOV压敏电阻ZNR100（用于浪涌保护）、X电容CX100（0.1μF）和共模扼流圈。这一部分的功能是滤除电网杂波并抑制电源本身对外界的电磁干扰。 17ips72 schematic work
[ AC Mains Input: 230V ] │ ▼ [ EMI / Input Filter ] │ ▼ [ Bridge Rectifier ] ───► [ Main Filter Cap: ~400V ] │ ┌─────────────────┴─────────────────┐ ▼ ▼ [ Standby & Main SMPS ] [ LED Backlight Driver ] (PWM IC: MP2012 / Similar) (Boost Converter) │ │ ┌──────────────┴──────────────┐ ▼ ▼ ▼ [ To LED Strips ] [ +5V Standby ] [ +12V Rail ] Key Hardware Sections
According to Badcaps forum discussions and repair videos, the 17IPS72 is prone to several common issues: A. TV is Completely Dead (No Standby Light) Measure voltage at LED output connector during power-on
If blown, inspect the bridge rectifier and MOSFETs for shorts.
Understanding the Vestel 17IPS72 Power Supply: A Deep Dive Schematic Analysis Overheating or weak startup circuit
The LED driver on the 17IPS72 is a boost converter circuit. Because LED strips require a high voltage to overcome the forward voltage drop of dozens of series-connected diodes, the 12V rail is stepped up.
If the voltage spikes high and then rapidly drops, the LED driver IC is detecting an open circuit—usually meaning one or more LEDs inside the panel have burned out.
A legitimate PDF schematic for the NM-B191/17IPS72 contains between 45 and 60 pages of critical data: