Garage Door Opener-Capacitor gone bad?

About a month ago my Liftmaster 1265 stopped running. It would just hum for about 2 seconds and stop. Liftmaster said the limit switch has been overrun, so I played with that. When I move the limit back, the opener hummed for 2 seconds, paused, and then hummed for 2 seconds with a slightly different pitch.
Someone here said the problem was probably a leaking capacitor. I took the cover off, but the capacitor looked fine. But when I touched the capacitor the opener suddenly started running. It was okay for 2 days, then stopped again. I touched the capacitor again and it ran okay for 5 minutes, then stopped. Now touching does not help.
I figured there was loose wire, but I sure can't find one. Liftmaster says it is probably a bad capacitor for $20; and if not that, a bad logic board for $85.
Does a bad capacitor make sense? Could touching a bad capacitor make it run for a while? Obviously they won't be taking the capacitor back if it doesn't help.
This is so so frustrating.
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Sounds like to me that PCB connection has broke lose from it's solder connection. Have a skilled electronics friend resolder the connection to the PCB board for you.
This message was written on 100% recycled spam. SAM >> samuelREMOVE snipped-for-privacy@myrealbox.com

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slightly
the
capacitor
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run
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Can you elaborate on what a PCB connection is, and how I identify it? All the wires are firmly attached, but if it is something smaller i wouldn't have seen it. Thanks.
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It's the Electronic or logic board. Is the cap soldered to that?
This message was written on 100% recycled spam. SAM >> samuelREMOVE snipped-for-privacy@myrealbox.com

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--------------- I'm can't help you troubleshoot the problem, but if you want to try a new capacitor, take the old one along with the wiring schematic to an electronics store. You can get a new one for under a dollar.
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Abe's idea is good.
This message was written on 100% recycled spam. SAM >> samuelREMOVE snipped-for-privacy@myrealbox.com

the
capacitor
stopped
says
board
run
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Abe wrote:

Hi, If it's starting cap for the motor. It will cost more than a dollar for sure. Tony
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electronics stores don't carry that size caps. i have an older liftmaster like this and same type problem , i tracked it down to the contacts were covered w/ carbon and other crap cleaned and fixed my problem. . then one of torsion springs broke
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toller wrote:

Hi, How is the capacitor mounted? On the body of motor? On a logic board? Any lead wires from capacitor? Then where is the wires going? No wires and mounted on a logic board, then vibration cracked solder joints causing intermittent problem. Resolder them and reinforce it with a drop of epoxy. Good luck, Tony P.S. You can't tell whether capacitor is good or bad by just looking.
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Well, that's not always true! Sometimes they burst, and you can easily see that they are bad. But, you are correct that a capacitor could look okay and be either good or bad.
BB
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toller wrote:

Did you remove the cover without disconnecting the AC power first? That can be risky, not only because of the potential for electric shock but also for the opener to start accidentally and grab your finger or hair.
I'd first disconnect the AC and see if the connections to the motor capacitor are loose. Reseat any push-on spade connectors, and tighten any screw eyelet connectors. If that doesn't help, then you may have a bad motor capacitor or a bad connection elsewhere. Vibration from the motor can make solder joints crack on the printed circuit board (PCB), but the cracks can be microscopic, so some technicians simply resolder almost everything (start with connectors and larger, heavier component connections).
Since the motor capacitor is an oil-filled one, it can be tested fairly well with just an ordinary volt-ohm meter -- see www.repairfaq.org for instructions and also for safety advice. These capacitors are available from almost any electrical supply but not from electronic supplies, which rarely carry oil-filled capacitors. Liftmaster is made by Chamberlain, which also makes Sears Craftsman openers, and Sears is sometimes cheaper for parts.
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toller wrote:

Did you remove the cover without disconnecting the AC power first? That can be risky, not only because of the potential for electric shock but also for the opener to start accidentally and grab your finger or hair.
I'd first disconnect the AC and see if the connections to the motor capacitor are loose. Reseat any push-on spade connectors, and tighten any screw eyelet connectors. If that doesn't help, then you may have a bad motor capacitor or a bad connection elsewhere. Vibration from the motor can make solder joints crack on the printed circuit board (PCB), but the cracks can be microscopic, so some technicians simply resolder almost everything (start with connectors and larger, heavier component connections).
Since the motor capacitor is an oil-filled one, it can be tested fairly well with just an ordinary volt-ohm meter -- see www.repairfaq.org for instructions and also for safety advice. These capacitors are available from almost any electrical supply but not from electronic supplies, which rarely carry oil-filled capacitors. Liftmaster is made by Chamberlain, which also makes Sears Craftsman openers, and Sears is sometimes cheaper for parts.
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replying to toller, Matt wrote: The capacitor can cause it not to run because that is what gives the motor the initial start you can get a capacitor at homedepot or at any garage door dealer just be sure and put the wires in the same place
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On Saturday, February 5, 2005 at 10:34:50 AM UTC-6, toller wrote:

IF he doesn't have it working after 11 years, it isn't worthwhile replying to him
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