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irobot
Joined: 13 Mar 2009 Posts: 49
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Posted: Sat Apr 04, 2009 7:36 pm Post subject: Samsung LCD Monitor 943BX |
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Hi All
I have a Samsung 943BX - need to get the case apart.
Anyone know the location of the tabs or any other hints?
Again, another situation where manufacturer refuses to use screws.
Thanks much. |
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jts1957
Joined: 24 Nov 2008 Posts: 2476 Location: Far, Far Away
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Posted: Sat Apr 04, 2009 11:31 pm Post subject: |
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A thin flat flexible "putty knife" and patience works well (in most cases) for me. |
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irobot
Joined: 13 Mar 2009 Posts: 49
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Posted: Sun Apr 05, 2009 12:29 am Post subject: Samsung (Sung what?!) 943BX |
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Thanks jts1957 for the reply. I did get it open earlier, just after my first post. It's just like the Dell's and all the rest. Patience is the key.
By the way - Here's a tip - I use one of the skinny flat 6" steel rulers with tape over the insertion end to protect the plastic. It works pretty well.
Anyhow, what I have is screen comes on briefly, then fades very rapidly until screen is blank. All voltages on PS remain up and steady, (3.3V, 5V, 15V).
Obviously a problem with the inverter.
HV transformer windings are both about 1000 ohms. Diodes all look good.
Any ideas? Havn't used the scope yet to check the osc. Any known common faults with these Sammies?
Thanks. |
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jts1957
Joined: 24 Nov 2008 Posts: 2476 Location: Far, Far Away
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Posted: Sun Apr 05, 2009 4:37 am Post subject: |
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Dell makes [some] Samsung's (OR Samsung makes [some] Dell's)? Anyway its been my observation that one is in cahoots with the other.
I'm assuming no "puffed lytics" in the power supply or inverter?
If inverter is the only problem, by shining a flashlight at various angles, you should still see whatever was on the screen before it blanked (or don't input anything and will usually display a test/pattern).
The voltages you mentioned must be presented to the inverter for it to run (B-Plus for outputs and rest of inverter circuitry, and a turn-on signal). Holding a scope probe above each transformer winding should show a "sinewave" (at least for the period the screen is on). Also inverters are "balanced" so that if some component/value is off for one portion, the circuit will detect that and shut down.
Test each backlight bulb by plugging in each one (by itself) at a time. |
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Justmanuals
Joined: 21 Aug 2004 Posts: 1948
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Posted: Sun Apr 05, 2009 5:30 am Post subject: |
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Dell doesn't manufacture anything itself. Some if it's monitors are Sony or Samsung and it's printers are Lexmark, Samsung, Xerox or Fuji. With the model and or the chassis number you can usually find out who actually made a product.
HtH
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irobot
Joined: 13 Mar 2009 Posts: 49
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Posted: Wed Apr 08, 2009 8:59 pm Post subject: Samsung 943bx |
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Hi All
Thanks for the replies.
I did find a puffy electrolytic in the inverter. Replaced it and much to my surprise, still same problem.
If I keep cycling this thing on and off it eventually comes up and stays on and works good.
Obviously a thermal issue. Will try some cold spray.
I have many years (20+) at component level repair, but my knowledge is not up to par on these LCD monitors. |
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livewire
Joined: 23 Mar 2009 Posts: 19
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Posted: Fri Apr 17, 2009 5:59 am Post subject: Computer and office equipment repairs |
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You have to really see for yourself with a thin knife like object and loads of patience because the makings differ but basically it is just the same system of monitors that are widely available everywhere. |
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