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Equipment Repairs => LCD TV forum => Topic started by: ANDRASONI on May 22, 2019,05:49:08

Title: lcd tv SAMSUNG LE40R71B not work ,relay clicking
Post by: ANDRASONI on May 22, 2019,05:49:08
I have this TV equipped with the source BN44-00134A.Tv does not start, it is heard how the relay is continuously coupling and disconnecting. The stable voltage drop is STB = 6.5V, P-ON / OFF varies between 0.2-2.5V in normal operation = 2.6V) PFC between 360-385V (when going is 382V). All electrolytes, secondary-primary, have been changed, except the 220uF / 450V which is ok. In this state, if measure the voltage on the pins 1-2 to optocouplePCS802, the relay stay connect and tv work normally . I have replaced the PCS802,801, the ICS 802 (KIA431), the QP803, the QS801, the QS802 checked. If I stop(unplugged) and I restart the tv in a few minutes, it works normally, if I leave it a little longer, the defect returns. Any suggestion is welcome, I do not think it would a problem with
 the mainboard. Thank you!
 I attach the power supply+ inverter schematic model BN44-00134A
Title: Re: lcd tv SAMSUNG LE40R71B not work ,relay clicking
Post by: ANDRASONI on May 23, 2019,11:06:37
Resolved by replacing eeprom 24C32 (IC903) with empty memory (FF). Thanks!