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5 Oct 60 14.12.41
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29 Sep 2017 09.45.53
Thomson 32HE8022 LCD TV UGLY repair; set would not turn on - now never turns off (but hey it works!) ( ENGLISH )
( แปลเป็นไทย ) Thomson 32HE8022 ซ่อมแซม LCD TV UGLY; ชุดจะไม่เปิด - ตอนนี้ไม่เคยปิด (แต่ hey ทำงาน!)
I go through the steps I went through to restore functionality to a Thomson 32HE8022 LCD TV which would not exit standby mode.
In essence, the issue on this particular TV was on the mainboard, and can be summarised as follows:
1. Pin 10 (PSU_ON) on W6702F (stand-by microcontroller) never changes state; always low.
2. Heating the chip causes the pin to change state - chip is faulty
3. Jumpering pin 16 (3.3V VCC) to pin 10 (PSU_ON) forces PSU to turn on and the set to operate normally, however the PSU can never enter standby mode, so standby power consumption is now 12 W.
The PSU power-on pin on the mainboard was constantly low, stopping the PSU from ever exiting stand-by mode. Turning the PSU on by applying 3.3V at the pin on the PSU (while that pin was disconnected from the mainboard) would allow the TV to turn on and operate. Trying to force the pin high on the actual mainboard would cause it to sink current, indicating that the pin was being held down by a transistor.
Tracing the signal controlling the pin leads us to the W6702F stand-by display processor (16-pin DIP under the CA slot). This device takes command from the keypad (among other things) to do stuff while the TV is in stand-by mode. The power-on signal comes from pin 10, and this pin was being held constantly low.
Heating the chip up before connecting the mains caused the TV to operate normally, and cooling the chip causes the TV to fail, so the issue is likely internal to the chip. The issue was resolved by connecting a jumper from pin 16 (3.3 V VCC) on the chip to pin 10 (PSU_ON), forcing the PSU to always be on. This seems to allow the set to operate normally despite the W6702 malfunctioning, at a cost of drawing about 12 W in "standby", since the PSU can never turn off.
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5 Oct 60 14.12.41
[CENTER]Views: 258,801
29 Sep 2017 09.45.53
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ใหม่ เผยแพร่เมื่อ 17 พ.ค. 2016
UPDATE เพิ่มเติม วันเสาร์ที่ 9 กันยายน 2560 21.53.23
ENGLISH
PAGE 145
#2881
5 Oct 60 14.12.41
PAGE 130
#2597
9 Sep 2017 21.53.23
SPECIAL NEW ( 384 )
NEW ( 184 )
NEW NEW NEW ( 132 )
https://www.youtube.com/watch?v=JcGTT7zFQqY
ใหม่ เผยแพร่เมื่อ 17 พ.ค. 2016
UPDATE เพิ่มเติม วันเสาร์ที่ 9 กันยายน 2560 21.53.23
ENGLISH
PAGE 145
#2881
5 Oct 60 14.12.41
PAGE 130
#2597
9 Sep 2017 21.53.23
SPECIAL NEW ( 384 )
NEW ( 184 )
NEW NEW NEW ( 132 )
https://www.youtube.com/watch?v=JcGTT7zFQqY
Thomson 32HE8022 LCD TV UGLY repair; set would not turn on - now never turns off (but hey it works!) ( ENGLISH )
( แปลเป็นไทย ) Thomson 32HE8022 ซ่อมแซม LCD TV UGLY; ชุดจะไม่เปิด - ตอนนี้ไม่เคยปิด (แต่ hey ทำงาน!)
FFcossag
เผยแพร่เมื่อ 17 พ.ค. 2016
เผยแพร่เมื่อ 17 พ.ค. 2016
I go through the steps I went through to restore functionality to a Thomson 32HE8022 LCD TV which would not exit standby mode.
In essence, the issue on this particular TV was on the mainboard, and can be summarised as follows:
1. Pin 10 (PSU_ON) on W6702F (stand-by microcontroller) never changes state; always low.
2. Heating the chip causes the pin to change state - chip is faulty
3. Jumpering pin 16 (3.3V VCC) to pin 10 (PSU_ON) forces PSU to turn on and the set to operate normally, however the PSU can never enter standby mode, so standby power consumption is now 12 W.
The PSU power-on pin on the mainboard was constantly low, stopping the PSU from ever exiting stand-by mode. Turning the PSU on by applying 3.3V at the pin on the PSU (while that pin was disconnected from the mainboard) would allow the TV to turn on and operate. Trying to force the pin high on the actual mainboard would cause it to sink current, indicating that the pin was being held down by a transistor.
Tracing the signal controlling the pin leads us to the W6702F stand-by display processor (16-pin DIP under the CA slot). This device takes command from the keypad (among other things) to do stuff while the TV is in stand-by mode. The power-on signal comes from pin 10, and this pin was being held constantly low.
Heating the chip up before connecting the mains caused the TV to operate normally, and cooling the chip causes the TV to fail, so the issue is likely internal to the chip. The issue was resolved by connecting a jumper from pin 16 (3.3 V VCC) on the chip to pin 10 (PSU_ON), forcing the PSU to always be on. This seems to allow the set to operate normally despite the W6702 malfunctioning, at a cost of drawing about 12 W in "standby", since the PSU can never turn off.
--
THIS VIDEO IS RELEASED TO THE PUBLIC DOMAIN
To the extent possible under law, I have waived all copyright and related or neighbouring rights to this work, according to the Creative Commons CC0 affirmer. This means that anyone is free to use this content in any manner they see fit, without my objection. However, the video may still contain copyrighted content (images, video, audio, software, etc.) that does not belong to me. WHILE I DO NOT RESERVE THE RIGHTS OF ANY PART OF THIS VIDEO, THE COPYRIGHT OF THIRD-PARTY CONTENT STILL BELONGS TO ITS RESPECTIVE OWNERS. THE COPYRIGHT OF THIRD-PARTY CONTENT IS NOT WAIVED. THE VIDEO IS PROVIDED AS-IS, AND I DO NOT PROVIDE ANY GUARANTEE OF ITS QUALITY.
&&&&
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