Samsung 2253BW replaced caps and fuse still broken :(

[darkphreekquency]

Re: Samsung 2253BW replaced caps and fuse still broken

I think the general rule is no more than 20% out of range but these guys would know better than me.

I got my IC's in the mail from hong kong yesturday. Finally got the old ones off the board with some ribon,flux,desolderpump, magnet wire and lots of patience. Chipquick would have been the right option for sure as I had to repair a pad that partially pulled up. The glue on the bottom of the chips was really hard to break loose.

I just have a quick newbie question about the leads. on both top and bottom Ic's it looks like all the pins on one side (opposite pin 1) are actually connected by the small trough of solder. Does that make sense that they would all be shorted together on one side? I'm testing the pads and I just want to make sure now that their off its not just my screw up. Looking at the data sheet I don't understand how they could be functional that way but Its probably just my limited understanding of electronics. Man these things are small.

[darkphreekquency]

Re: Samsung 2253BW replaced caps and fuse still broken

so i replaced the IC's they are testing like they are connected well. When I plug it in I get a slight squeel then when I push the power button the blue light goes on and the squeeling goes away but no back-lights.

[darkphreekquency]

Re: Samsung 2253BW replaced caps and fuse still broken

ok so I went over all my connections again (at the top of the pins) and found two that were not working so I fixed it.

Now when I plug in the monitor I get a low squeel and when I turn the power on the squeel continues for a second then it fades out seems different then last time ... Thinking I should have just bought a board

[darkphreekquency]

Re: Samsung 2253BW replaced caps and fuse still broken

Any other suggestions as to what the issue could be ?

[PlainBill]

Re: Samsung 2253BW replaced caps and fuse still broken

Any other suggestions as to what the issue could be ?

'Technician error' seems to be the most likely problem.

I prefer to give explicit instructions, but the picture of the bottom of the power supply is so bad I can't read the labels, so you'll have to figure these steps out.

Do you get the proper voltages out of the power supply?

Does the inverter supply (12V?) get to the inverter?

What are the voltages on the inverter control pins (On/Off and Brightness)?

PlainBill

[darkphreekquency]

Re: Samsung 2253BW replaced caps and fuse still broken

Fixed it ... Surprisingly I actually soldered the IC's correctly. I replaced two more caps. 50v 10UF and a 16V 100uf. Had to use ones out of an old power supply but now the monitor works . I probably didn't need the ics after all but I should have just tried replacing every single cap.

To anyone else out there reading this. Do them all before anything else.

I made the mistake of only changing the common ones that were being talked about. None of the others looked blown but they were! Also, if your going to solder surface mount components get some chipquick and save some time and frustration. With a little practice and some good flux soldering the pads isn't too bad. Thank you guys for all your help I just have one last question

I am still hearing a feint electrical noise from the board but the monitor is working its almost inaudible with the casing open but I don't really imagine its normal. Do inverters usually give off a little noise or is it some sort of voltage issue?

<EDIT>
The squealing is there only when the monitor is off. When the lamps come on it goes away. When I turn the power off you can start to hear it again. Bad resistor maybe?

[joshnz]

Re: Samsung 2253BW replaced caps and fuse still broken

<EDIT>
The squealing is there only when the monitor is off. When the lamps come on it goes away. When I turn the power off you can start to hear it again. Bad resistor maybe?

my hp monitor does that done it for as long as i have had it.