View Full Version : Any RI area geeks than solder...


JohnR
11-08-2008, 09:42 AM
Any RI area geeks than desolder and re-solder about 4 - 6 capacitors on a PCB? Trying to resurrect an LCD monitor. Have found several articles on it and I can see the blown caps...

Beyond my level of digital risk taking...

UserRemoved1
11-08-2008, 10:33 AM
:wave: bring it up bossman I'll be home later and have a full smd station

spence
11-08-2008, 10:48 AM
:wave: bring it up bossman I'll be home later and have a full smd station
Saddo Massochism Dungeon?

If so be sure to post some pics! :hee: :lasso:

:devil2:

-spence

Pete F.
11-08-2008, 11:10 AM
Saddo Massochism Dungeon?

If so be sure to post some pics! :hee: :lasso:

:devil2:

-spence

For some reason this is really scary

UserRemoved1
11-08-2008, 11:25 AM
NO CHIT! :eek5:

For some reason this is really scary

JohnR
11-08-2008, 03:24 PM
That would be a high quality soldering unit, but we know where your mind is :shocked:

Scott - what time you be about? Bride is ill atm but let me see if I can break out later - still need to get the caps

UserRemoved1
11-08-2008, 04:50 PM
I may have something here John if you can give me the values I'll look for you. Tell me if they look like little oil cans or better yet shoot me a closeup digital with the values and I can look here first. I got alot of that stuff.

I'm here whenever you want to do it. Gimme a call at the house 5082787128

JohnR
11-08-2008, 09:10 PM
2 bulging caps - the rest are flat (large pics)

http://www.striped-bass.com/images/caps/badcaps1.jpg

http://www.striped-bass.com/images/caps/badcaps2.jpg

http://www.striped-bass.com/images/caps/badcaps3.jpg

I ran into this article and found the same condition on a slightly older version of the same board: http://www.fixya.com/support/t123065-monitor_displays_breifly_goes_blank

Well my Acer AL1711 finally gave up in as much as the screen flashed briefly at switch-on then went blank, regardless of brilliance setting so I decided to take it apart and try to fix it. The good news is that IT WAS NOT THE LAMPS that I feared in my earlier post and was easier than I had ever dreamed! First allow a good period of time for the internal components to discharge before starting. Remove the plastic clip at the base hinge to expose 4 screws - remove all four to release the stand. Then remove the 4 black cross head screws that appear to hold the back on, they do but there is more to do. Carefully tease the silver surround away from the case, best to start in the centre of each side and finish at the corners. There are many plastic clips to release before the surround comes away. Now remove the four cross head screws holding the pushbutton switch circuit board. The whole assembly can now be removed from the case and reveal a metal cover held by 2 SHORT (remember that!) SHORT! threaded machine screws. These once removed will allow the case to be slid away from the holding tabs located down the edges of the cover and removed. Now unplug the connectors from the board that has the mains input connector attached to it. You will see a heatsink with 4 electrolytic caps above it. Silly ACER designers, have placed the capacitors so that they get all the heat from the heatsink! Yes folks, the capacitors are above the heatsink when the monitor is in its normal operating position! So all the convected heat dries them out, nice. So the fault is due to a silly design error!
Replace all 4 capacitors, two of them are 1000uF at 16V and the other two are 470uF at 16V, all radial types. Try and get capacitors with the highest operating temperature, at least 105 degree types and remember these are polarised, make sure you connect the capacitor + wire to + on the circuit board. You should have no problems with re-assembly but don't put the wrong screw where the short ones went or you are liable to see it come out of the screen LOL! Most important - - Don't forget the screw holding the earth tag to chassis. Good Luck, you will be amazed how much brighter the screen is now!

http://www.fixya.com/Uploads/Images/232EAE6.JPG

Raven
11-08-2008, 09:31 PM
heh heh heh


http://i25.photobucket.com/albums/c66/ravenob1/SaltyBuger.jpg

UserRemoved1
11-09-2008, 04:49 AM
yea I should have those at the house or definitely something that will work there. Those are filter caps in the dc power supply section meant to filter the AC ripple out of that diode bridge next to them. Typically if the top of the caps is bulging it means they've been hit with a higher voltage than they are rated for. I would not be so concerned about a slight bulge as I would be a shorted cap or leaky (electrically) that would eff that up. Easy nuff to test them anyways.

Years ago we used to initiate the new guy by plugging a few of them into his bench ac strip so when he turned his bench on it went KABLOOIE :D They don't like AC :hee:

Hey I got to pickup a couple of kick presses in Cranston this afternoon how bout you meet me there and give me an extra pair of hands to load then we can go back to uxbridge and we'll fix that? Bring all you need to run it and we'll hook it up to a pooter there.

UserRemoved1
11-09-2008, 04:57 AM
I read that link John and what they say makes complete sense. If I don't have the caps also there's a rat shack up the road about 4 miles but i'm pretty sure I got all that stuff they're pretty standard values. Size will probably be the most important consideration.

JohnR
11-09-2008, 06:41 PM
Scott - you da man! Going to put it back together tonight :btu:

UserRemoved1
11-09-2008, 07:15 PM
Hey glad we were able to find it John. Salty's LCD Repair...hmmm :D

naaaaaa

BobT
11-10-2008, 09:45 AM
Hay Scott........fixing is fine but what caused them to blow? How the tooth?