Hello to fellow Samsung sufferers.
My name is Michael and I have a discarded 2493HM with very low mileage which I believe (wish) can be fixed. My knowledge of electronics is severly limited compared to all you guys in this forum, and my voltmeter is a cheap joke. But I have a simpler question in the end.
I have read all the other posts about the samsung 2493hm and other samsungs with same power supply (BN44-00195A) but have not found the same problem description anywhere for this monitor.
The symptom: Screen turns on->Backlight flashes like crazy from the first moment and never stops, does not go black after two seconds. Signal from PC or monitor messages appear just fine (so I assume logic board is ok). Blue led steady on, controls are responsive, and the floating input box on screen flashes to photoepileptic levels.
Bonus symptom after changing caps on inverter: Intermittent audible high pitch sound from either inverter or power board that starts before the ccfls start flashing but match in frequency when they try to turn on (sound and flashing)
No bulging caps on power board but yellow glue between two resistors and diode turned black (and has been removed now), resistors look messed up but measure ok when unsoldered.
No visible arcing on inverter board, or smell of ozone (if that applies to these screens, I have played with some old flybacks in the past and know the smell well)
My failed remedies after reading possible solutions on badcaps.net: Changed all caps (also 82μf 450V), voltage across IC is ~390V when on. Changed two yellow caps on inverter. Resoldered many joints. The brand of the caps I used is something called Lelon(?) from a local electronics store, they might not be the best but from what I read on this forum they can't be worse than the one Samsung uses
Good news is after all my horrible soldering and tinkering is that it's not worse.....alas it's also not better.
Note: When all but one (any) of the ccfl are unplugged then it does not flash, add a second ccfl and it starts flashing.
Since my skills in electronics don't allow me to do much more, I am asking if there is a way for me to know which component is at fault (Power board or inverter) so I can order the damn piece from somewhere and settle the feeling of not wasting 24". Even thought of converting the screen to LED...but must do further research.
My name is Michael and I have a discarded 2493HM with very low mileage which I believe (wish) can be fixed. My knowledge of electronics is severly limited compared to all you guys in this forum, and my voltmeter is a cheap joke. But I have a simpler question in the end.
I have read all the other posts about the samsung 2493hm and other samsungs with same power supply (BN44-00195A) but have not found the same problem description anywhere for this monitor.
The symptom: Screen turns on->Backlight flashes like crazy from the first moment and never stops, does not go black after two seconds. Signal from PC or monitor messages appear just fine (so I assume logic board is ok). Blue led steady on, controls are responsive, and the floating input box on screen flashes to photoepileptic levels.
Bonus symptom after changing caps on inverter: Intermittent audible high pitch sound from either inverter or power board that starts before the ccfls start flashing but match in frequency when they try to turn on (sound and flashing)
No bulging caps on power board but yellow glue between two resistors and diode turned black (and has been removed now), resistors look messed up but measure ok when unsoldered.
No visible arcing on inverter board, or smell of ozone (if that applies to these screens, I have played with some old flybacks in the past and know the smell well)
My failed remedies after reading possible solutions on badcaps.net: Changed all caps (also 82μf 450V), voltage across IC is ~390V when on. Changed two yellow caps on inverter. Resoldered many joints. The brand of the caps I used is something called Lelon(?) from a local electronics store, they might not be the best but from what I read on this forum they can't be worse than the one Samsung uses
Good news is after all my horrible soldering and tinkering is that it's not worse.....alas it's also not better.
Note: When all but one (any) of the ccfl are unplugged then it does not flash, add a second ccfl and it starts flashing.
Since my skills in electronics don't allow me to do much more, I am asking if there is a way for me to know which component is at fault (Power board or inverter) so I can order the damn piece from somewhere and settle the feeling of not wasting 24". Even thought of converting the screen to LED...but must do further research.
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