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How easy to change a cap?

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First post, by Geon106

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Hey all,

I have a Geforce Ti4200 which has no display and on inspection one of the caps is bulging like crazy. So I thought changing all 4 of the caps that are the same might bring the card back to life.

I have a super cheap soldering iron with variable temperature and some solder and flux etc. I can find capacitors online with the same capacitance but slightly higher voltage rating which from what I read is fine(can be any number above but not more than 20% below?).

My question is, I have never soldered in my life. I have watched some YouTube videos which make it look super easy but I'm not convinced I'd be capable.

So my question to you wonderful people is how easy is it to solder/de-solder? What do I need to be careful of and is having a cheap iron going to make it an impossibly difficult task?

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Reply 2 of 25, by Geon106

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wiretap wrote on 2020-03-27, 22:26:

Very easy, even with cheap equipment. Refer to the guide in my signature.

Thank you, I downloaded your guides, opened the first and it was quite intimidating, opened the second and is exactly what I am after. Appreciate it

1993:A500
1995:A1200
1997:Apricot MS540|P/166|16M|Rage3D 2M
2000:PB 9533|P3/533|128M|Voodoo3 2000 16M
'04:Custom|P4/3G|1GB|NVIDIA 5700 256M
'07:Custom|AMDX2/3.2Ghz|4GB|8800 GTX
'11:Custom|i5 2500k|16G|AMD 7950
'16:Custom|i5 6600k|16G|NVIDIA 1080|SB AE-5

Reply 3 of 25, by derSammler

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The Ti4200 is already RoHS compilant, so soldering on that is not that easy if you are a beginner. Getting the cap out requires more heat and some flux if you don't want to cause damage.

I'd suggest to get some broken piece of hardware first and do some training on that.

http://retro-net.de/blog.html

Reply 4 of 25, by computerguy08

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Avoid any soldering iron without a base unit. You will waste your time and damage the board in the process.

The best way is to have a temperature adjustable soldering station with a flat tip, add fresh solder and yank the part out little by little. This way you will avoid prolonged heat exposure.

The easiest way to clean the hole afterwards is to use a 0.8mm drill bit. It takes seconds.

derSammler wrote on 2020-03-28, 08:29:

The Ti4200 is already RoHS compilant, so soldering on that is not that easy if you are a beginner. Getting the cap out requires more heat and some flux if you don't want to cause damage.

I'd suggest to get some broken piece of hardware first and do some training on that.

I agree. Sometimes it is a pain in the butt to remove capacitors from newer motherboards (after the 90's).

Reply 5 of 25, by Geon106

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computerguy08 wrote on 2020-03-28, 09:18:
Avoid any soldering iron without a base unit. You will waste your time and damage the board in the process. […]
Show full quote

Avoid any soldering iron without a base unit. You will waste your time and damage the board in the process.

The best way is to have a temperature adjustable soldering station with a flat tip, add fresh solder and yank the part out little by little. This way you will avoid prolonged heat exposure.

The easiest way to clean the hole afterwards is to use a 0.8mm drill bit. It takes seconds.

derSammler wrote on 2020-03-28, 08:29:

The Ti4200 is already RoHS compilant, so soldering on that is not that easy if you are a beginner. Getting the cap out requires more heat and some flux if you don't want to cause damage.

I'd suggest to get some broken piece of hardware first and do some training on that.

I agree. Sometimes it is a pain in the butt to remove capacitors from newer motherboards (after the 90's).

Thanks guys, I will try on an older board first before moving to this one. I mean this card is already broken so no loss but of course I want to have the best chance of saving it rather than binning.

I will find someone to practice on until the new caps arrive then I will try it slowly and carefully. The soldering iron I have looks like it goes up to 500oC. I might when times aren't so tough invest in a slightly better iron with a proper base station/sponge/wire coil etc

1993:A500
1995:A1200
1997:Apricot MS540|P/166|16M|Rage3D 2M
2000:PB 9533|P3/533|128M|Voodoo3 2000 16M
'04:Custom|P4/3G|1GB|NVIDIA 5700 256M
'07:Custom|AMDX2/3.2Ghz|4GB|8800 GTX
'11:Custom|i5 2500k|16G|AMD 7950
'16:Custom|i5 6600k|16G|NVIDIA 1080|SB AE-5

Reply 6 of 25, by _UV_

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For such a new PCB it doesn't matter what iron you use, even old unregulated 40-60W from 70s with 5mm tip is ok for recap and can't damage board or traces, just use more flux and solder on the joint. What matters - tip size = thermal capacity, avoid using needle or pen style tips, use C, D or K 4mm+.

Last edited by _UV_ on 2020-03-29, 09:05. Edited 1 time in total.

Reply 7 of 25, by derSammler

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_UV_ wrote on 2020-03-29, 09:01:

even old unregulated 40-60W from 70s with 5mm tip is ok for recap and can't damage board or traces

Did you ever do any soldering at all?

http://retro-net.de/blog.html

Reply 8 of 25, by _UV_

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derSammler wrote on 2020-03-29, 09:04:
_UV_ wrote on 2020-03-29, 09:01:

even old unregulated 40-60W from 70s with 5mm tip is ok for recap and can't damage board or traces

Did you ever do any soldering at all?

Yep, i even have more than simple iron. Believe me desoldering with good old copper iron my dad used is the best experience for recaping. For heat sensitive shitty boards i have JBC.

PS
Two most common problem for newcomers with modern irons:
- supplied tip shape, usually I or B
- oxidation of a such tip and solder joint.
With both of this you can't melt solder fast enough and continue to heating PCB and component without result.

Reply 9 of 25, by computerguy08

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_UV_ wrote on 2020-03-29, 09:01:
even old unregulated 40-60W from 70s with 5mm tip is ok for recap and can't damage board or traces […]
Show full quote

even old unregulated 40-60W from 70s with 5mm tip is ok for recap and can't damage board or traces

Yep, i even have more than simple iron. Believe me desoldering with good old copper iron my dad used is the best experience for recaping. For heat sensitive shitty boards i have JBC.

PS
Two most common problem for newcomers with modern irons:
- supplied tip shape, usually I or B
- oxidation of a such tip and solder joint.
With both of this you can't melt solder fast enough and continue to heating PCB and component without result.

Just saying, there is a reason soldering stations are more expensive than irons. I had a few of those irons in the past (both cheap and branded ones) with proper tips. It just never worked well, parts wouldn't stick together, it was a horrible experience for me.

When I got my own soldering station a while ago, a cheap Gordak unit with a flat tip, it was so much easier to solder. Obviously it ain't as good as a genuine Hako, but it does a really good job. Nowadays I can't imagine doing soldering without temperature control. PCBs have all kinds of solder (RoHS, good old leaded solder), it really helps if you have the right temperature, to avoid instant flux evaporation or incapability to melt lead-free stuff.

To give credit where is due though, sometimes a big powerful iron may be useful when dealing with a large thermal mass (ground planes), but generally, the soldering station should cover the most cases.

Reply 10 of 25, by _UV_

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computerguy08 wrote on 2020-03-29, 10:40:

Just saying, there is a reason soldering stations are more expensive than irons. I had a few of those irons in the past (both cheap and branded ones) with proper tips. It just never worked well, parts wouldn't stick together, it was a horrible experience for me.

When I got my own soldering station a while ago, a cheap Gordak unit with a flat tip, it was so much easier to solder. Obviously it ain't as good as a genuine Hako, but it does a really good job. Nowadays I can't imagine doing soldering without temperature control. PCBs have all kinds of solder (RoHS, good old leaded solder), it really helps if you have the right temperature, to avoid instant flux evaporation or incapability to melt lead-free stuff.

Thermal capacity of tip, good flux and fresh solder doing main work, not soldering station. You need to control temperature to avoid possible damage to weak PCB or component. I have no issues with desoldering ROHS components with old copper iron without regulation, just need proper flux and wet tip.

Reply 11 of 25, by computerguy08

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_UV_ wrote on 2020-03-29, 10:53:

Thermal capacity of tip, good flux and fresh solder doing main work, not soldering station. You need to control temperature to avoid possible damage to weak PCB or component. I have no issues with desoldering ROHS components with old copper iron without regulation, just need proper flux and wet tip.

I agree. Tip quality does matter. But the issue is that, if you end up buying a soldering iron (a brand new one, not talking about used equipment), you will likely get a poor quality unit (just like you said). I consider a soldering station a wise investment, because you have the possibility to deal with weak PCBs (e.g. old soviet PCBs will easily be destroyed by such an unregulated iron). These are just my opinions ofc 😉

Reply 12 of 25, by ShovelKnight

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Old Soviet PCBs are shit anyway. I remember fixing several Soviet amplifiers and some of them had lifted tracks and bodge wires right from the factory.

You do need a thermostatic iron but it doesn't mean you need a soldering station. There are good thermostatic irons that are the same size as a regular dumb iron.

Reply 13 of 25, by _UV_

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Well, about PCBs of Soviet period< yes they are weak that is a result of using old technology for mass production for too long, about 15 years. Look at earlier mass equipment from Japan or even USA till maybe 1985 it will be same, look at the chinese "goods" till maybe 2005 it will be the same.

Reply 14 of 25, by Miphee

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Using a 230V soldering iron for desoldering is like using depleted uranium ammo to hunt deer.
It gets the job done but it's crude and dangerous.
Regulating iron temperature is important to avoid tip oxidation and flux burning. Yes, a 230V iron gets the job done under ideal circumstances but desoldering doesn't always go smoothly. This is when lower temperatures come in handy and higher temperatures damage the board.
Remember, we are talking about computer parts, not old television or radio circuits with wide traces, big solder joints and large spaces between components.

Reply 15 of 25, by Geon106

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Well guys, I gave it a go anyways. I set the iron to 300oC and put some flux on both pins. I used the solder with the flat tip.

After a few goes of melting followed by using the solder sucker, there was not much happening. However I grabbed the cap with a pair of pliers and gently pulled whilst using the iron on both pins (alternating between them every few seconds) and after a few minutes the cap slowly worked free and out.

I don't know if I have done it properly or damaged anything, but when the replacement caps arrive over the coming days I will try and solder them on and report back 😀

I think I will definitely invest in a soldering station though even if a fairly cheap small one. This iron is dangerously unstable in its little holder and feels super cheap (I'm just thankful it even has adjustable temperature as some don't)

1993:A500
1995:A1200
1997:Apricot MS540|P/166|16M|Rage3D 2M
2000:PB 9533|P3/533|128M|Voodoo3 2000 16M
'04:Custom|P4/3G|1GB|NVIDIA 5700 256M
'07:Custom|AMDX2/3.2Ghz|4GB|8800 GTX
'11:Custom|i5 2500k|16G|AMD 7950
'16:Custom|i5 6600k|16G|NVIDIA 1080|SB AE-5

Reply 16 of 25, by aha2940

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Geon106 wrote on 2020-03-29, 15:09:

Well guys, I gave it a go anyways. I set the iron to 300oC and put some flux on both pins.

Just to be clear here: where are you getting these numbers from? I ask because 3000°C is extremely high temperature, it's almost twice the melting point of titanium and platinum, and near the melting point of tungsten (3422°C), which is the highest melting-point metal on Earth, so that can't be correct. Either that, or the C after your 3000 has a different meaning.

Reply 17 of 25, by computerguy08

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aha2940 wrote on 2020-03-29, 15:19:

Just to be clear here: where are you getting these numbers from? I ask because 3000°C is extremely high temperature, it's almost twice the melting point of titanium and platinum, and near the melting point of tungsten (3422°C), which is the highest melting-point metal on Earth, so that can't be correct. Either that, or the C after your 3000 has a different meaning.

I think he meant 300 °C