Capactitor question

MDE

Lifer
Jul 17, 2003
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I'm replacing the caps on my old Epox 8KHA motherboard which I really don't care about, but would like to have it up as a Folding rig and pseudo HTPC. If I mess it up too badly I'll pick up a Fry's combo. Here's my shopping list:

12W pencil tip soldering iron
Solder wick for any possible goof ups
Solid core solder
12 2200 uF 10V caps
7 1200 uF 6.3V caps -4 of these are the only ones currently blown
4 1200 uF 10V caps

How important is it that I get caps rated spot on? What would be a safe deviation on the capacitance and voltage?
 

CraigRT

Lifer
Jun 16, 2000
31,440
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Hi there, you might want to visit this thread just for some info I posted up: Motherboard forum

I have recently replaced some caps (7) on my Soltek SL-75FRN2-L motherboard, and it works flawlessly.

with capacitors, as long as the uF rating is spot on,(don't play with the uF rating, make sure it's exact, they are not hard to find) the voltage can be higher. its like memory. PC3200 can run in a system that requires only PC2100.. backwards compatible. but if your caps need to be 10v, and you can only get 6.3.. no dice.

I can even show you pics of the motherboard with the new caps.. it's in my system working perfectly as we speak with the new caps.
 

MDE

Lifer
Jul 17, 2003
13,199
1
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Cool, nice to know. So the voltage rating is just the highest voltage the cap will tolerate? I'm a bit rusty on my electronics, gotta dig up the old electronics soldering project from a couple years ago...
 

CraigRT

Lifer
Jun 16, 2000
31,440
5
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Originally posted by: MDE
Cool, nice to know. So the voltage rating is just the highest voltage the cap will tolerate? I'm a bit rusty on my electronics, gotta dig up the old electronics soldering project from a couple years ago...

Yep, thats correct.. I have 16V caps on my mobo now, which were 6.3V before. no problems at all because before and after they are still 3300uF. so this also means less chance of having the caps go bad (because their tolerance is higher)
 

Demon-Xanth

Lifer
Feb 15, 2000
20,551
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I'd recommend getting a solder sucker instead of relying on the wick. They cost about $10 iirc for an okay one. They do a better job at cleaning out the holes.
 

MDE

Lifer
Jul 17, 2003
13,199
1
81
Originally posted by: Demon-Xanth
I'd recommend getting a solder sucker instead of relying on the wick. They cost about $10 iirc for an okay one. They do a better job at cleaning out the holes.
I've used the wick before, but the sucker may come in handy later on if I decide to mod the Xbox like I planned.
 

CraigRT

Lifer
Jun 16, 2000
31,440
5
0
I don't even use a wick/sucker for this type of thing
I use the existing solder, and it's so little the iron doesn't collect anything.
 

Jeff7

Lifer
Jan 4, 2001
41,596
20
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I was informed that I would need low-ESR capacitors (equivalent series resistance) in order to give very clean power to the CPU and various other components - my 8RDA+ died a little while back and needed work.
Some advice quick:
You might need more than 30W. My 30W iron from Radio Shack couldn't do a thing to the solder; a cheap 35W I got with a toolkit barely could do the job. I finally bought a 40W soldering iron from Radio Shack - it did the job. Epox used some really high-temp solder on my board.
 

Demon-Xanth

Lifer
Feb 15, 2000
20,551
2
81
The high temp solder is probably silver solder. Lead solder melts around 450F or so, so an iron at 550F is pleanty, and 650F (which I recommend) does easily. Silver solder melts at 550F.

Edit: I noticed you have solid core solder, I'd recommend getting some flux. It helps out more than you'd think.