I just had an HP f1703 LCD monitor with an unusual fix and thought I'd pass on the info.
Unit would loose the picture about 2 seconds after power up, and the power LED stayed lit. The back light inverter board was shutting down and I initially suspected the caps. Pulled a few and they tested OK for value.
Then I noticed a fractured solder joint on a toroidal inductor lead. A little soldering and it's back in business. I guess the high frequency vibration caused the connection to fail with time since the unit is from 2003.
Bad caps have been the cause of every LCD monitor failure I've worked on until now...... hey live and learn. Reminds me a bit of repairing CRT's when a common fault was fractured connections on the power resistors caused by thermal cycling.
So keep on checking the caps but keep an eye on the coils too!
David
Unit would loose the picture about 2 seconds after power up, and the power LED stayed lit. The back light inverter board was shutting down and I initially suspected the caps. Pulled a few and they tested OK for value.
Then I noticed a fractured solder joint on a toroidal inductor lead. A little soldering and it's back in business. I guess the high frequency vibration caused the connection to fail with time since the unit is from 2003.
Bad caps have been the cause of every LCD monitor failure I've worked on until now...... hey live and learn. Reminds me a bit of repairing CRT's when a common fault was fractured connections on the power resistors caused by thermal cycling.
So keep on checking the caps but keep an eye on the coils too!
David
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