[deleted]
A VGA monitor may be easier to repair than you think
121–128 of 128 posts
Re: A VGA monitor may be easier to repair than you think
#122Since the title specified a resolution, I assumed a VGA CRT with a DB15 connector. (Not an MDA, CGA or EGA) I was all set to warn you kids about the dangers of CRTs, high voltage, Xrays, and of course the implosion if you break the neck of the tube... and instead got bad capacitors on LCD displays. Regardless of what the safety standards say, you should always remove power, and short any capacitors with a screwdriver…
> short any capacitors with a screwdriver Not universally a good idea to do that, especially not in a power supply. Safe enough in some circumstances but not all. Better to buy a discharge probe or make one by soldering a 2200 ohm 5w resistor between a couple of insulated wires. EDIT: made it less condescending.
Things can fail open, a screwdriver can't. What's wrong with putting a dead short once across a capacitor? I've been doing it for 40 years in the interest of safety. Usually the bleeders are done and nothing happens anyway.
Re: A VGA monitor may be easier to repair than you think
#123Since the title specified a resolution, I assumed a VGA CRT with a DB15 connector. (Not an MDA, CGA or EGA) I was all set to warn you kids about the dangers of CRTs, high voltage, Xrays, and of course the implosion if you break the neck of the tube... and instead got bad capacitors on LCD displays. Regardless of what the safety standards say, you should always remove power, and short any capacitors with a screwdriver…
Thanks. I appreciate when someone gives safety advices as they come in handy when starting to tinker electronics. When repairing dishwasher I had to disconnect a huge capacitor... well it looked like it. Knowing what you just wrote about capacitors, it gave me shrugs and I was VERY careful handling that piece of thing. Can you give any advice on what good fume extractor for soldering does and if hobbyist that does re…
A fume extractor with an activated charcoal filter grabs up the organic solvents that were used as flux to help make a good solder connection, and keep them out of your lungs. They don't cost much, but if smoke goes in, and doesn't come out, its helping, even if it isn't perfect.
Re: A VGA monitor may be easier to repair than you think
#124Re: A VGA monitor may be easier to repair than you think
#125Earlier quoted context omitted.
This might be a nice feature of a multimeter: discharge mode. Putting the leads over a capacitor, the multimeter will show the voltage and discharges the capacitor with a constant safe current. Beeps can be used to indicate when the capacitor is safe to handle or not.
It kind of already has a discharge mode, just short the leads of the capacitor with one of the probes.
That is not how you properly discharge a capacitor, though. Especially big ones.
Re: A VGA monitor may be easier to repair than you think
#126Earlier quoted context omitted.
> short any capacitors with a screwdriver Not universally a good idea to do that, especially not in a power supply. Safe enough in some circumstances but not all. Better to buy a discharge probe or make one by soldering a 2200 ohm 5w resistor between a couple of insulated wires. EDIT: made it less condescending.
Things can fail open, a screwdriver can't. What's wrong with putting a dead short once across a capacitor? I've been doing it for 40 years in the interest of safety. Usually the bleeders are done and nothing happens anyway.
Nothing, as long as it's a low voltage capacitor. Do it to a filter cap in a power supply and you'll have a huge spark and probably damage your screwdriver. Best practice if you're working with large capacitors is to discharge it (safely, using the tool I described), and confirm it worked using a voltmeter.
I learned dealing with 600V monster filter capacitors in vacuum tube power supplies, they'll happily vaporize a screwdriver and knock you off your feet in the process.
Re: A VGA monitor may be easier to repair than you think
#127Earlier quoted context omitted.
If there are vertical lines most likely Cof or T-Con board failure. Unfortunately it isn't an easy repair. (Although some YouTube videos show you can work around some minor cof failures by isolating broken lines with a tape)
Yeah iirc (too lazy to get it out of the closet to test) it was vertical lines that somewhat fade in throughout the screen, with colors resembling what it's supposed to be displaying.
sounds like a case of stuck pixels
Re: A VGA monitor may be easier to repair than you think
#128Earlier quoted context omitted.
>they had available on hand had a different "number" on it, but they assured me it was a higher rating and wouldn't affect use It's probably the amount of farad units the capacitor is rated for. You can often use a capacitor with higher farads as long as the voltage is the same and it can be even more reliable than the original part, the only trouble is sometimes they are physically larger or taller, so you have to b…
Seems more likely that it would be the voltage rating? While it’s true that a larger capacitance would be fine in many applications, it wouldn’t always be (e.g. if the cap is part of an RC filter or if it’s used as a bypass cap). In contrast the voltage rating of a cap is just a maximum.
I think you are right, I might've got it mixed up!