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Internal Power supply for Dell 1800FP Monitor 6870T445D10

 
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majamer



Joined: 07 Dec 2007
Posts: 2

PostPosted: Fri Dec 07, 2007 7:27 pm    Post subject: Internal Power supply for Dell 1800FP Monitor 6870T445D10 Reply with quote

Hello,

This monitor does not power up anymore. The power button has an LED flickering constantly. I tested the internal power supply (P/N: LG 6870T445D10) and found that both 5VDC and 12VDC outputs have 5VDC and 12VDC as expected. However, I hear a clicking sound matching the LED flickering coming out of an area where the 2AS01 fixed frequency controller is located. Can I consider this power supply dead although it's producing the correct output voltage. Why would the power supply give this clicking sound? I'm a newbie trying to learn while saving some money.

Thanks,

Martha
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vtech



Joined: 08 May 2006
Posts: 1264
Location: USA

PostPosted: Fri Dec 07, 2007 10:48 pm    Post subject: Reply with quote

The reason for LED flicker could be anything from dried capacitors, bad regulation or simply an external load causing it to shutt down? Are you absolutley sure there are no other lines beside the 5& 12 volt? From your description, sounds like there may be a problem on the main board?

Not familiar with the unit, but here is an older thread about it on arstechnica

http://episteme.arstechnica.com/eve/forums/a/tpc/f/67909965/m/380005925731/p/1
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majamer



Joined: 07 Dec 2007
Posts: 2

PostPosted: Sat Dec 08, 2007 4:57 am    Post subject: Reply with quote

The only connector that goes from the power board to the main board has 6 pins, 4 of them are GND and two 5VDC and two 12VDC. When I tested each of the + pins I got the avertized voltage so I assumed that the power adapter is doing what's supposed to do. However, there's this clicking sound which resonates exactly with the power LED flickering which tells me that the source of the problem is the power adapter not the main board since the clicking occurs even when the main board isn't connected. I would have ordered the power adapter if I was certain that it was dead.
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emmet
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PostPosted: Wed Mar 05, 2008 6:06 am    Post subject: Reply with quote

try using the +12v,+5v and G. from your computer power sappy
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SZASZ



Joined: 27 Apr 2007
Posts: 69
Location: TIMISOARA

PostPosted: Mon Mar 24, 2008 8:04 pm    Post subject: Reply with quote

Whery strange Shocked sow like you said with or with out mainboard connected the power suply does the same.

I bellive you have a some defective capacitors maybe the 120uF/400V.
Second thing that you should check is the part "TL431".

If this two ideeas not help, I dont know if the inverter is placed togheter with the power board, you should check the transisitors on inverter.

Try disconecting the inverter 12V and see that the monitor work, I mean that the led is still flashing?[/code]
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