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deronmoped
Joined: 03 Nov 2006
Posts: 1154
Location: San Diego
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| Posted: Sun Jun 20, 2010 11:05 pm Post subject: Capacitor pee and recapping? |
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When a cap starts to leak on the circuit board, does the junk now on the circuit board effect the operation of it?
Now when you have a board with like a hundred caps on it, is there any way to replace all those caps without putting out lots of dollars? Is there some place that specializes in just refreshing a circuit board?
Thanks, Deron.
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cmjohnson
Joined: 03 Apr 2006
Posts: 5180
Location: Buried under G90s
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| Posted: Sun Jun 20, 2010 11:13 pm Post subject: |
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Yeah, that stuff is acidic and will literally eat the copper traces right off the circuit board.
So you'd better clean it all up and replace ALL the electrolytic caps.
CJ
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CZ Eddie
Joined: 23 Mar 2006
Posts: 1601
Location: Austin, TX
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| Posted: Sun Jun 20, 2010 11:55 pm Post subject: |
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Send the board off to Curt or DraganM. Either one would probably recap for a slight fee. Curt might even attach a warranty to it.
If the board is full of the same value cap, then you might check eBay for bundles? Otherwise, just start hitting the usual places. A lot of caps are anywhere from $0.10 to $1.50 each.
Do you still have your 10PG on the huge curved screen?
_________________
Back after a digital sabatical.
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garyfritz
Joined: 08 Apr 2006
Posts: 12088
Location: Fort Collins, CO
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| Posted: Mon Jun 21, 2010 2:18 am Post subject: |
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Better check with Curt/Dragan before you send the board.  I think Dragan was getting a bit burned out on pulling caps. And he was specialized for Marquee boards -- unless you bought all the caps your board needs, he's not likely to have the right ones on hand.
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draganm
Joined: 08 Mar 2006
Posts: 8990
Location: Colorado
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| Posted: Mon Jun 21, 2010 5:38 am Post subject: |
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curt will do it, I don't do repairs as a general rule and only do the MArquee mod's through the forum. Caps are fairly easy though, ask for the high temp. 105C versions from Panasonic.
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deronmoped
Joined: 03 Nov 2006
Posts: 1154
Location: San Diego
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| Posted: Mon Jun 21, 2010 6:33 am Post subject: |
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| CZ Eddie wrote: | Send the board off to Curt or DraganM. Either one would probably recap for a slight fee. Curt might even attach a warranty to it.
If the board is full of the same value cap, then you might check eBay for bundles? Otherwise, just start hitting the usual places. A lot of caps are anywhere from $0.10 to $1.50 each.
Do you still have your 10PG on the huge curved screen? |
I got rid of that screen, could never get the silver paint perfect. Bought a HP from Dalite. I was real happy initially with that screen, now that thing has a line across it. Where the screen rolls over a seam, it has now did something to it to cause a faint wide line all the way across it. Called a rep and he knew exactly what I was talking about. I'm leaving the screen down to see if the line goes away.
What a waste, pay big bucks for a supposedly well made screen and it has a defect built into it. Then it doubly sucks that they know about the defect and sell the screen anyways.
Deron.
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deronmoped
Joined: 03 Nov 2006
Posts: 1154
Location: San Diego
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| Posted: Mon Jun 21, 2010 6:55 am Post subject: |
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This is like the third video out board that I have now swapped out.
One of them would have what looked like a brighter then normal green on start up. This would correct itself after a while.
Another board worked but took like ten minutes before I got a image.
With this latest board the red and green would take a minute to come on. Then the red would flicker for a few minutes before it would stabilize.
Make that the forth video board. I just found another one that would have no image come up.
No idea why I'm having so many problems with these boards (well actually the PJ has been eating all kinds of boards). The heat sink only gets warm. I'm guessing the caps are failing, but then again I have other boards in the PJ I have never had problems with.
Deron.
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draganm
Joined: 08 Mar 2006
Posts: 8990
Location: Colorado
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| Posted: Mon Jun 21, 2010 3:14 pm Post subject: |
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| deronmoped wrote: | No idea why I'm having so many problems with these boards (well actually the PJ has been eating all kinds of boards). The heat sink only gets warm. I'm guessing the caps are failing, but then again I have other boards in the PJ I have never had problems with.
Deron. |
Capacitors are more or less like battery's, not designed to last forever despite many claims to the contrary by some folks here. Also, a lot of times they are specced at the very limit of survivability by the manufacturer to save money. I had a friend just a couple weeks ago with a 2 year old $2200. samsung Plasma that quit working. A quick Google search showed bad caps on the DC power board. The 3300uf 10 volters, 9 of them, had blown out the top. It was a 20 minute fix for me as a favor to him (good friend of mine)
Looking at the PG video out board I must say that is a huge number of AL caps. Probably a few hours to swap them all out. the rest look like dipped Tantalums, high quality wire wound resisotrs, Inductor chokes, FET's, and through hole mounted amps and such which generally don't go bad for a very long time (more than 10 years)
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macgyver655
Joined: 22 Aug 2007
Posts: 8508
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| Posted: Mon Jun 21, 2010 3:17 pm Post subject: |
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[/quote] Capacitors are more or less like battery's, not designed to last forever despite many claims to the contrary by some folks here. [/quote]
Who are these folks? I'm trying to remember anyone saying this.
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draganm
Joined: 08 Mar 2006
Posts: 8990
Location: Colorado
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| Posted: Mon Jun 21, 2010 3:22 pm Post subject: |
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looking at the board more closely you can see a few caps placed very closely to the upper heat sink and the large transisotrs clipped to it. Generally as a rule you never place caps next to heat sources but sometimes it's unavoidable and I won't criticize since i'm not an EE  In this pic it's hard to tell but the larger one in upper left corners looks like it's starting to swell?
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draganm
Joined: 08 Mar 2006
Posts: 8990
Location: Colorado
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| Posted: Mon Jun 21, 2010 3:23 pm Post subject: |
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| macgyver655 wrote: | | Who are these folks? I'm trying to remember anyone saying this. |
sorry, no names please
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macgyver655
Joined: 22 Aug 2007
Posts: 8508
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| Posted: Mon Jun 21, 2010 3:26 pm Post subject: |
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| draganm wrote: | | macgyver655 wrote: | | Who are these folks? I'm trying to remember anyone saying this. |
sorry, no names please |
Oh, ok. I didn't think anybody said that. Are you just making up stuff again, lol. 
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draganm
Joined: 08 Mar 2006
Posts: 8990
Location: Colorado
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| Posted: Mon Jun 21, 2010 6:56 pm Post subject: |
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| macgyver655 wrote: | | draganm wrote: | | macgyver655 wrote: | | Who are these folks? I'm trying to remember anyone saying this. |
sorry, no names please |
Oh, ok. I didn't think anybody said that. Are you just making up stuff again, lol. |
I was Paraphrasing. MAybe no one ever said "caps last forever" but close enough. Maybe it was "caps don't go bad nearly as often or as quickly as people think they do", whatever that means? Kinda ambiguous
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macgyver655
Joined: 22 Aug 2007
Posts: 8508
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| Posted: Mon Jun 21, 2010 7:33 pm Post subject: |
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| draganm wrote: | | Maybe it was "caps don't go bad nearly as often or as quickly as people think they do", whatever that means? Kinda ambiguous |
Ok, again, who said that? You want to open up a can of worms again? Everything has been quiet and not commenting on you.
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deronmoped
Joined: 03 Nov 2006
Posts: 1154
Location: San Diego
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| Posted: Mon Jun 21, 2010 8:49 pm Post subject: |
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| draganm wrote: | | looking at the board more closely you can see a few caps placed very closely to the upper heat sink and the large transisotrs clipped to it. Generally as a rule you never place caps next to heat sources but sometimes it's unavoidable and I won't criticize since i'm not an EE In this pic it's hard to tell but the larger one in upper left corners looks like it's starting to swell? |
I was kinda wondering how much heat that large heat sink was removing. So last night I fired up the PJ and put my finger on it after a few minutes. It was just warm to the touch, maybe after a hour or so it might have gotten much warmer, going to have to test the temperature after a movie.
I really think there must be several things going on to cause caps to fail. What makes me think this is, I have other electronic devices that never see a cap failure, even after decades. We know heat accelerates the demise of them, but what else are candidates that cause them to fail sooner. A good reason to know this is, why replace all the caps on a board, especially when there is close to a hundred of them, when all you really need to do is replace the ones that are only going to last half as long?
I'm going to try replacing the caps that are near any heat source on this board and see what that does. Other then that, anyone know which caps are usually suspect?
Thanks, Deron.
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garyfritz
Joined: 08 Apr 2006
Posts: 12088
Location: Fort Collins, CO
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| Posted: Mon Jun 21, 2010 8:58 pm Post subject: |
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Could be that your devices that never fail are using way under-spec'd caps. Running those things at low temps extends their lifespan considerably. Run them closer to the edge and they die a lot quicker.
You might want to try to find an ESR meter that will let you test the caps in-circuit. Then you'll know exactly which ones need to be pulled.
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macgyver655
Joined: 22 Aug 2007
Posts: 8508
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| Posted: Tue Jun 22, 2010 2:31 am Post subject: |
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| garyfritz wrote: | Could be that your devices that never fail are using way under-spec'd caps. Running those things at low temps extends their lifespan considerably. Run them closer to the edge and they die a lot quicker.
You might want to try to find an ESR meter that will let you test the caps in-circuit. Then you'll know exactly which ones need to be pulled. |
See everyone, Gary pays attention... 
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deronmoped
Joined: 03 Nov 2006
Posts: 1154
Location: San Diego
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| Posted: Tue Jun 22, 2010 4:40 am Post subject: |
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| garyfritz wrote: | Could be that your devices that never fail are using way under-spec'd caps. Running those things at low temps extends their lifespan considerably. Run them closer to the edge and they die a lot quicker.
You might want to try to find an ESR meter that will let you test the caps in-circuit. Then you'll know exactly which ones need to be pulled. |
I have a ESR meter, but they seem to be of limited use. The caps that leak test OK and caps that I replaced before with a bad ESR reading made no difference.
Deron.
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Sparky015
Joined: 12 May 2009
Posts: 1185
Location: Cleveland / Akron, OH
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| Posted: Tue Jun 22, 2010 12:29 pm Post subject: |
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Deron,
Sounds like you may have a bum ESR meter, or it's out of calibration. If a cap is leaky, it will most certainly read out of spec on an ESR meter. Also, are you comparing your readings to the cap datasheet? There are all different kinds of caps, some designed for low ESR, some not. It's important you have a hard spec you are testing to, to understand if the cap is outside it's normal characteristics.
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~Paul
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dturco
Joined: 06 Feb 2009
Posts: 3778
Location: Eastern Shore Maryland
TV/Projector: Runco DLP VX-3000i Marquee 9500 parts doner
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| Posted: Tue Jun 22, 2010 1:21 pm Post subject: |
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You know what we need? A sub forum with live feed cameras showing Curt demonstrating the meter usage on these parts and an in depth set up of a few of a P/Js.
CurtPalmeOnlineschool.com Register now for classes.
Course requirements a working P/J, the Tech manual for that model P/J, an ESR Meter, a Digital multi meter and?
Course cost $500
Schiemflug explained and demonstrated in advanced courses. [This ones very popular bandwidth is filling up now.]
CurtPalmeOnlineschooladv.com Advance class.
 
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Firefly rules. Can't stop the signal.
http://www.hulu.com/firefly
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