Aleks
Member
Hello all,
I have an Samsung 940MW which had this problem : for some time it worked and then suddenly it powered off.
I traced the problem to the PSU unit which had leaky and bad output caps.
I changed all of them with the correct values except two which were in parallel and they added up with a total value of 1640 uF/25V (two * 820uF/25V). In their place I put two caps with the values : 1000uF/30V and one with 680 uF/25V.
The problem now is, when I plug the power cord, the green status led turns on for about 2 seconds and then goes off and I can't switch on the monitor.
I've measured the output from the PSU power line which goes to the monitors control board and has the following markings :
BL_EN, BL_CTL, 5V, 5V, GND, GND, GND, 13V, 13V
between GND and the 5V connectors I have 5V output and between GND and the 13V connectors I have 13V. Between GND and BL_EN or GND - BL_CTL I have 0 volts.
What might be the problem ? Is the fact that the value of the two parallel caps is different (40uF difference) causing the PSU to malfunction ?
Regards,
Aleks
I have an Samsung 940MW which had this problem : for some time it worked and then suddenly it powered off.
I traced the problem to the PSU unit which had leaky and bad output caps.
I changed all of them with the correct values except two which were in parallel and they added up with a total value of 1640 uF/25V (two * 820uF/25V). In their place I put two caps with the values : 1000uF/30V and one with 680 uF/25V.
The problem now is, when I plug the power cord, the green status led turns on for about 2 seconds and then goes off and I can't switch on the monitor.
I've measured the output from the PSU power line which goes to the monitors control board and has the following markings :
BL_EN, BL_CTL, 5V, 5V, GND, GND, GND, 13V, 13V
between GND and the 5V connectors I have 5V output and between GND and the 13V connectors I have 13V. Between GND and BL_EN or GND - BL_CTL I have 0 volts.
What might be the problem ? Is the fact that the value of the two parallel caps is different (40uF difference) causing the PSU to malfunction ?
Regards,
Aleks