I have a Samsung SyncMaster 940n monitor, three years old, it comes on for 5-6 seconds then turns black. It doesn't attain the normal blue color before going black. Other posts suggest needing to replace a capacitor and fuse. Is this what I need to do? And what is a good source for these parts?
Rcpips, You may need to replace one or possibly 5 -8 aluminum can "electrolytic filter capacitors" on the "switch-mode-power-supply/CCFL inverter board. If, as you say "works for 5 or 6 seconds" then that means that fuse is good. Another thing you will need to inspect SMPS board for is "cold" "frosty looking" solder joints where the components (surface mount or through hole) are soldered to the copper circuit traces. May need large magnifying glass or low power inspection microscope to locate them. Resolder any that look bad or loose. Some solder joints have thinner than "hair" thermal fractures that can also cause YOUR TYPE OF SYMPTOM!! PARTS: digikey. mouser. newark. and possibly Radio Shack. If buying filter capacitors, make sure they are rated 105 deg C only!! NOT 85 deg C!!! If caps need to be replaced (swollen, leaky) be sure to tell us the brand name you find installed on your unit! CAPXON, ELITE, JUN-FU are just 3 that you don"t want to find in your unit. BAD news if you do!! If DIY suits you, remember to document with "close-up" digital stills your unit tear-down, so you can reassemble unit without any "extra" parts laying on kitchen table!! Filter capacitors are polarized. You put them in + to +, - to -!!! if you put them in backwards they go BOOOOMMM!!! Hope this helps a little. lmistyrel on aim or 12fixlouie at fixya.
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rcpips, go to www.thinksrs.com to see my lcr meter. here are some readings of capacitance of CapXon failed units I have removed. 2200uf 16v =45.2uf, 1500uf 16v=9.01uf, 1500uf 15v=4.9uf These units have only very slight swelling of their top aluminum "can". Other units with more swelling are just as bad. If possible remove some of them and have a local tech at a tv /or other repair shop measure them. I wonder what Samsung would say if you told them what you found??? Keep me posted on this issue!!! 12fixlouie
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Thanks for your quick response. You said "bad news if I find CAPXON" caps in unit. Well that's what I found. Also after careful visual inspection, I have yet to find any broken or cracked solder connections nor do I see any caps that visually look distorted on either board. I will continue to inspect, but if you have any further suggestions, I welcome the input.
On another post,http://www.fixya.com/support/t2748440-mo... my board looks the same and the problem is similar. But I still don't see any visible evidence the cap shown there is a problem in my case. But I would replace it and try it if that is the most likely problem.
rcpips
Thanks for your quick response. You said "bad news if I find CAPXON" caps in unit. Well that's what I found. Also after careful visual inspection, I have yet to find any broken or cracked solder connections nor do I see any caps that visually look distorted on either board. I will continue to inspect, but if you have any further suggestions, I welcome the input.
On another post,http://www.fixya.com/support/t2748440-mo... my board looks the same and the problem is similar. But I still don't see any visible evidence the cap shown there is a problem in my case. But I would replace it and try it if that is the most likely problem.
rcpips
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