A VGA monitor may be easier to repair than you think • Hacker News Board

Re: A VGA monitor may be easier to repair than you think

#91

Post by BizarroLand » Thu, Sep 09, 2021, 4:39 PM UTC

raxxorrax wrote: post #68

ksec wrote: post #11

Earlier quoted context omitted.

The answer isn't socketed but high quality capacitor ( Solid or Tantalum etc ) . Swollen capacitor should really be a thing of the past. Unfortunately Capacitor is an area that is easiest to cut cost and has no immediate effect on the devices function and are hard to spot. Part of the reason why I switch over to Mac ~20 years ago. I dont want to spend time looking at every capacitor on a motherboard or to gather enou…

> Capacitor marketing on motherboard was a thing. That is a thing? What do they advocate, the fine smell of rotten eggs when they die?

Last mobo I bought proudly talked about their "Military Grade Capacitors" which is funny because if you know anything about Military Grade that means "whoever will provide a product that meets minimum spec for the least amount of money"

Re: A VGA monitor may be easier to repair than you think

#92

Post by BizarroLand » Thu, Sep 09, 2021, 4:42 PM UTC

kalium-xyz wrote: post #13

contravariant wrote: post #7

Earlier quoted context omitted.

Though it'd be nice if they made those kinds of things more easily accessible, rather than hiding it behind tons of warranty stickers and really tiny screws.

Sure, just saying that it not being socketed should not be that big a barrier to entry. If you want an awesome way of doing things look at old tektronix scopes https://w140.com/tekwiki/wiki/Ceramic_Strips

I'm assuming that the reason why there's so much discussion about soldering techniques and practice on that page is that the tubes failed on a predicable schedule and user servicing the machine was a mandatory part of ownership, right?

Re: A VGA monitor may be easier to repair than you think

#93

Post by mytdi » Thu, Sep 09, 2021, 4:47 PM UTC

HPsquared wrote: post #38

Waterluvian wrote: post #21

Earlier quoted context omitted.

What do bleed resistors drain towards if the ground wire has been unplugged by unplugging the monitor?

A charged capacitor has a surplus of electrons on one side, and a shortage on the other. A bleed resistor allows current to flow from one side to the other, balancing the charges on both sides so there is no relative voltage. Q=CV

Great explanation, very helpful! Thank you!

Re: A VGA monitor may be easier to repair than you think

#94

Post by dehrmann » Thu, Sep 09, 2021, 4:47 PM UTC

MisterTea wrote: post #39

squarefoot wrote: post #17

I've repaired several TVs and monitors, LED lamps, etc. just by replacing bad capacitors, and in a few cases some diodes too, so it's worth trying especially on electronics that would otherwise be thrown away. If you see a TV/monitor going off randomly or a LED lamp starts flashing, pretty sure there are one or more defective capacitors in there. Defective capacitors are a common plague in modern electronics, and the…

Aye I remember bringing back a lot of dead monitors, TV's and even a cheap Pentium 4 motherboard by swapping caps. A place I worked at had a bunch of 19" Optiquest LCD monitors which ALL eventually died from a single bad cap on the power supply board. I fixed every one of those monitors, think it cost less than $10 to order the caps from digikey.

How do you figure out which ones are bad?

Re: A VGA monitor may be easier to repair than you think

#95

Post by [deleted] » Thu, Sep 09, 2021, 4:50 PM UTC

dehrmann wrote: post #94

MisterTea wrote: post #39

Earlier quoted context omitted.

Aye I remember bringing back a lot of dead monitors, TV's and even a cheap Pentium 4 motherboard by swapping caps. A place I worked at had a bunch of 19" Optiquest LCD monitors which ALL eventually died from a single bad cap on the power supply board. I fixed every one of those monitors, think it cost less than $10 to order the caps from digikey.

How do you figure out which ones are bad?

[deleted]

Re: A VGA monitor may be easier to repair than you think

#96

Post by [deleted] » Thu, Sep 09, 2021, 4:59 PM UTC

BizarroLand wrote: post #91

raxxorrax wrote: post #68

Earlier quoted context omitted.

> Capacitor marketing on motherboard was a thing. That is a thing? What do they advocate, the fine smell of rotten eggs when they die?

Last mobo I bought proudly talked about their "Military Grade Capacitors" which is funny because if you know anything about Military Grade that means "whoever will provide a product that meets minimum spec for the least amount of money"

[deleted]

Re: A VGA monitor may be easier to repair than you think

#97

Post by hellbannedguy » Thu, Sep 09, 2021, 5:08 PM UTC

fouc wrote: post #70

grishka wrote: post #61

Earlier quoted context omitted.

Huh. I have a Dell monitor that suddenly started showing these kind of smeared stripes instead of a proper picture. Took it apart, looked carefully at all the capacitors and other components on both boards, but none looked bad. Disconnecting and reconnecting the ribbon that goes to the LCD panel made no difference whatsoever. What could it possibly be?

does a bad capacitor always show damage visibly?

no

Re: A VGA monitor may be easier to repair than you think

#98

Post by kalium-xyz » Thu, Sep 09, 2021, 5:22 PM UTC

BizarroLand wrote: post #92

kalium-xyz wrote: post #13

Earlier quoted context omitted.

Sure, just saying that it not being socketed should not be that big a barrier to entry. If you want an awesome way of doing things look at old tektronix scopes https://w140.com/tekwiki/wiki/Ceramic_Strips

I'm assuming that the reason why there's so much discussion about soldering techniques and practice on that page is that the tubes failed on a predicable schedule and user servicing the machine was a mandatory part of ownership, right?

The tubes are socketed. Not sure if the soldering was entirely meant for the users or for specialized maintainers, might have been a mix. these things cost the price of a new car and came with similar responsibilities. The soldering techniques are to prevent bad contacts or impurities as this is sensitive measurement equipment.

Re: A VGA monitor may be easier to repair than you think

#99

Post by grishka » Thu, Sep 09, 2021, 5:24 PM UTC

kasabali wrote: post #89

grishka wrote: post #61

Earlier quoted context omitted.

Huh. I have a Dell monitor that suddenly started showing these kind of smeared stripes instead of a proper picture. Took it apart, looked carefully at all the capacitors and other components on both boards, but none looked bad. Disconnecting and reconnecting the ribbon that goes to the LCD panel made no difference whatsoever. What could it possibly be?

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.

Re: A VGA monitor may be easier to repair than you think

#100

Post by spookthesunset » Thu, Sep 09, 2021, 5:35 PM UTC

mdip wrote: post #67

I think more than a few of us are familiar with the mess of bad capacitors that made their way into products throughout the early 00s. I still see this from time to time, but I remember the first time I encountered it -- I had purchased a $200 SageTV Media Streamer (v1) and it failed a few months out of warranty. I replaced it with a v2 and put the v1 in the basement. Then Google bought SageTV[0] and they stopped pro…

> Then Google bought SageTV[0] and they stopped producing software/products.

Man I remember when that happened. I was happy for the SageTV devs but I knew that was the end of a great run. SageTV was our DVR for years... It was such a cool product!