Hi,
I´m trying to fix a three year old Samsung LCD for a friend and this one seems a bit tricky for me. When powered on, the set starts up for a second, backlight (LED) lits up, OSD is displayed but just for a second and then turns off again. This repeats every two seconds until I cut the power off from the outlet. It´s the onboard relay of the PSU that "clicks".
There´s no difference in behaviour if I disconnect the main board and/or the LED backlight, except that the cycle is a bit slower (due to lower PSU load I presume). To me it sounds like an overload protection that takes place and puts it into "hicc up-mode" .
All the capacitors seem fine visually, however I have the proper equipment to both measure them and replace if considered necessary.
Any ideas? I´ve made a brief measuerment on diodes and FET´s without any obvious signs of shorting out.
Please see the attached photos.
I´m trying to fix a three year old Samsung LCD for a friend and this one seems a bit tricky for me. When powered on, the set starts up for a second, backlight (LED) lits up, OSD is displayed but just for a second and then turns off again. This repeats every two seconds until I cut the power off from the outlet. It´s the onboard relay of the PSU that "clicks".
There´s no difference in behaviour if I disconnect the main board and/or the LED backlight, except that the cycle is a bit slower (due to lower PSU load I presume). To me it sounds like an overload protection that takes place and puts it into "hicc up-mode" .
All the capacitors seem fine visually, however I have the proper equipment to both measure them and replace if considered necessary.
Any ideas? I´ve made a brief measuerment on diodes and FET´s without any obvious signs of shorting out.
Please see the attached photos.
Attached Files
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