Samsung SyncMaster T240 2-second backlight problem
Hello all,
I'm so glad to have found this forum. Looks like a great place to hang out and learn a great many things!
I come to you with a misbehaving Samsung SyncMaster T240. As I understand, this is a common issue. I'm just looking for a little advice.
I've pulled it apart and compared the power/inverter board with that of another ancient T240 thread on here (that didn't seem to get resolved, that one).
It looks very much the same - there's a browning around the transformer/cap area in the same place as these other boards I've seen. From what I understand, this can be due to normal heating in operation.
I'm not sold that it's a blown transformer. A pic of a blown transformer on this board looks greatly different, and I've attached one below (the first image with camera flash on. As you can see, my own doesn't look at all like that. Neither did those from the other threads).
I've confirmed one of the two CCFL output sockets is dead. Using the top CCFL cable from the panel, if I plug it into the "bottom" channel, it lights up, waits two seconds, then shuts off. If I plug it into the "top" channel (where it is supposed to be) nothing lights up at all. This means both sets of CCFLs are working (the bottom set of CCFLs were the ones that came on and off originally, so if the top work too...), thus the problem is with the board.
So... what to do? Should I change those purple caps by the transformer? They don't look bad at all, which is why I'm confused.
It's been a hot few months though, and I reckon the high temperature pushed the board over the edge. I'm hoping the caps have just died on me and I can change them, but I'd rather know if I'm looking in the wrong place before I start making changes. The less I fiddle with the board, the better!
Thanks for your time!
EDIT: Oops, just saw this thread where a helpful chap said if the secondaries on the transformer were off in resistance then it was probably blown.
I had a go, and got 1.3Kohm on the secondary coil connected to the channel which isn't working, and roughly 0.93Kohm on the secondary for the channel where everything worked.
I haven't removed the transformer - could these readings simply be due to it still being connected to other stuff in the board? I hope so. Capacitors are easier to get hold of then one of these flippin' things...
I'm so glad to have found this forum. Looks like a great place to hang out and learn a great many things!
I come to you with a misbehaving Samsung SyncMaster T240. As I understand, this is a common issue. I'm just looking for a little advice.
I've pulled it apart and compared the power/inverter board with that of another ancient T240 thread on here (that didn't seem to get resolved, that one).
It looks very much the same - there's a browning around the transformer/cap area in the same place as these other boards I've seen. From what I understand, this can be due to normal heating in operation.
I'm not sold that it's a blown transformer. A pic of a blown transformer on this board looks greatly different, and I've attached one below (the first image with camera flash on. As you can see, my own doesn't look at all like that. Neither did those from the other threads).
I've confirmed one of the two CCFL output sockets is dead. Using the top CCFL cable from the panel, if I plug it into the "bottom" channel, it lights up, waits two seconds, then shuts off. If I plug it into the "top" channel (where it is supposed to be) nothing lights up at all. This means both sets of CCFLs are working (the bottom set of CCFLs were the ones that came on and off originally, so if the top work too...), thus the problem is with the board.
So... what to do? Should I change those purple caps by the transformer? They don't look bad at all, which is why I'm confused.
It's been a hot few months though, and I reckon the high temperature pushed the board over the edge. I'm hoping the caps have just died on me and I can change them, but I'd rather know if I'm looking in the wrong place before I start making changes. The less I fiddle with the board, the better!
Thanks for your time!
EDIT: Oops, just saw this thread where a helpful chap said if the secondaries on the transformer were off in resistance then it was probably blown.
I had a go, and got 1.3Kohm on the secondary coil connected to the channel which isn't working, and roughly 0.93Kohm on the secondary for the channel where everything worked.
I haven't removed the transformer - could these readings simply be due to it still being connected to other stuff in the board? I hope so. Capacitors are easier to get hold of then one of these flippin' things...
Attached Files
Comment