Cody
Bob Vance, VR
Premium
join:2002-05-28
Mukilteo, WA
clubs:
| Capacitor question (replacing capacitor in monitor)
I have a Gateway 20.1" monitor that turns on and flickers and then turns off, and cycles infinitely. There is no picture on it as the cycles are about 1/4 second long. I took it apart and I believe I found the culprit. I have experience soldering but I don't have much experience with buying capacitors. I know the inherit dangers of Capacitors and I left this one alone for a while to let it discharge before handling, and I checked it with a multimeter prior to handling.
My question is this:
The capacitors say 16v470uf on them, I'm going to check radio shack but their website doesn't seem to show these, so I'm likely to order some on the internet. Is there anything else I should look for in them? Here are the two capacitors I'm going to replace. Please give me any concerns or advice you feel is necessary, thank you!
Cody
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Kringle
Dr.D
Premium
join:2004-02-27
Pierrefonds, QC
 ·Bell Sympatico
3 edits | Looks like a Nichicon #UHE1C471MPD6, Digikey part #493-1523-ND and they go for $0.35 ea. plus shipping.
Don't just use any electrolytic cap as the leakage current is rather important. What you have is a very normal capacitor failure due to a bad electrolyte batch that occurred with a number of well known manufacturers (rumour has it because of industrial espionage) and the Nichicons don't have the problem. Only two of the caps appear to have failed (bulging tops) but it is best to swap out all three. The other one will probably fail in relatively short order as well.
Do you know how to remove and replace caps on a multi-layer board without wrecking the board? If you don't have experience in this area I can put together some instructions for you.
EDIT: While you're at it, you should check for other caps that exhibit the same visual problem, purchase and swap them out as well.
Digikey: »www.digikey.com/
EDIT (the second):
As far as replacing caps on a multi-layer board is concerned, this is a wonderful Recapping Tutorial from BadCaps.net. Start with the Overview, then Cap Removal, Cap Installation and then check out the Testing Pointers. |
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kruser
Premium
join:2002-06-01
Saint Louis, MO
clubs:
3 edits | reply to Cody
I'd replace all three.
Kringle beat me to it!
In addition, pay attention to polarity so you insert the new ones correctly! |
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Kringle
Dr.D
Premium
join:2004-02-27
Pierrefonds, QC
·Bell Sympatico
| said by kruser  :In addition, pay attention to polarity so you insert the new ones correctly! Awww, c'mon. Don't you think it's fun to watch people install caps backwards and see their expressions when they power up the board? I think that they make just dandy firecrackers! 
Seriously though, that's good advice and it's a good thing to mark the plus on the board with a felt marker before unsoldering the caps. |
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IllIlIlllIll
EliteData
Premium
join:2003-07-06
Lindenhurst, NY | reply to Cody
id replace those with 25 volt 470 uF |
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SmokChsr
Who let the magic smoke out?
Premium
join:2006-03-17
Saint Augustine, FL
| said by IllIlIlllIll :id replace those with 25 volt 470 uF I would up the voltage as well just be sure to check the diameter and make sure they will physically fit. |
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Kringle
Dr.D
Premium
join:2004-02-27
Pierrefonds, QC | reply to IllIlIlllIll
In close to 50 years of repairs, I've never found a need to change the design specs when using quality replacement components such as the part I referred to. |
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kruser
Premium
join:2002-06-01
Saint Louis, MO
clubs:
·AT&T Southwest
| said by Kringle :In close to 50 years of repairs, I've never found a need to change the design specs when using quality replacement components such as the part I referred to. I agree but only 35 years of repairs here  |
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SparkChaser
BURY BECK
Premium
join:2000-06-06
Downingtown, PA
 ·Verizon FIOS
 ·Comcast
1 edit | reply to Cody
If you want to go RS »www.radioshack.com/product/index···e=family
Check the lead spacing |
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SmokChsr
Who let the magic smoke out?
Premium
join:2006-03-17
Saint Augustine, FL
| reply to Kringle
said by Kringle :In close to 50 years of repairs, I've never found a need to change the design specs when using quality replacement components such as the part I referred to. In 31 years of repairs in many cases I will "upgrade" a part. Typically what I determine is that the part was designed very close, if not too close to spec, in an attempt to save $.002 in manufacturing costs.
I'm sure in 50 years, you've seem a failure that as soon as you saw the symptoms you were able to say, darn C2 puked on the PS board again. I know quite a few times I walk into a service location with the exact needed part already in my hand going only on the complaint. Seldom have I had to come back out to exchange it for a different part.
In this particular case, their is no harm and only extra safety margin by going to the next higher voltage rating. provided it will fit. In filter circuits I often up the voltage and the capacity if I know I can get away with it. |
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SparkChaser
BURY BECK
Premium
join:2000-06-06
Downingtown, PA | reply to Cody
We sure have a lot of old experienced guys here |
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Kringle
Dr.D
Premium
join:2004-02-27
Pierrefonds, QC | Older than dirt. |
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Kringle
Dr.D
Premium
join:2004-02-27
Pierrefonds, QC
·Bell Sympatico
| reply to SmokChsr
said by SmokChsr :I'm sure in 50 years, you've seen a failure that as soon as you saw the symptoms you were able to say, darn C2 puked on the PS board again. I know quite a few times I walk into a service location with the exact needed part already in my hand going only on the complaint. Seldom have I had to come back out to exchange it for a different part. Exactly why I was able to provide the Digikey part number and price on the spur of the moment.
The only reason why I say I don't think a voltage upgrade is necessary is because these caps are from one of the manufacturers that had the infamous electrolyte problem. Out of the 200 odd caps that I've replaced on motherboards using the Nichicons as replacements, none have failed since (with no change to the voltage spec). I'm talking about motherboards that only lasted about 2 years from the OEM and the first ones I repaired have been happily running 24/7 since 2001.
Most often I find crappy component quality and not crappy design specs. Where the board builders save their money is by buying cheaper components and the difference between a "League" and a "Nichicon" in batches of 10,000 could be about 5¢. That could mean about 50¢ per board which really adds up. The difference in cost between a 16V and a 25V within the same manufacturer at those quantities is not as pronounced.
Granted, if you up the voltage on a cap, you can get away with a lesser quality cap.
I think, however, that this is really a case of the old Certs commercial: "Stop, you're both right!"  |
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SparkChaser
BURY BECK
Premium
join:2000-06-06
Downingtown, PA
·Verizon FIOS
·Comcast
| reply to Kringle
said by Kringle :Older than dirt. I'm right behind you.
OT-your mention of Digikey. They have a lot of my money this year. They have to be one of the best organized companies. I put an order in yesterday at 2PM and got a shipping confirmation at 5PM. That's pretty good service. |
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TheMG
join:2007-09-04
Edmonton, AB | Yup, DigiKey has always been fast for me too. The Purolator delivery guys on the other hand... not as much (understaffed I think). |
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Cody
Bob Vance, VR
Premium
join:2002-05-28
Mukilteo, WA
clubs:
1 edit | reply to Cody
Thank you Kringle kruser IllIlIlllIll SmokChsr , SparkChaser and TheMG !
I'm going to try to head to radio shack today because my m-f is very busy with work and class right now, and it would be wonderful to have this back up and running in the meantime. I read through each of those articles, thank you! I will have to pick up a couple things from RS anyway it seems. Assuming shipping isn't more than a couple dollars, I will order from that first website as well so I will have backups, because my girlfriend's aunt and uncle have this year's version of this monitor and I'd like to be prepared in case it dies out of warranty. Thanks again everyone! I will post about how well (or horribly wrong) it goes!
edit:after checking the lead spacing, of course
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Cake or Death |
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