How to exchange caps - tutorial

Discussion in 'Modding' started by trodas, Oct 4, 2013.

  1. trodas

    trodas Member

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    A little photo guide about how I do it :) Dedicated to Datsun 1600 - thank you, dear friend :thumbup:

    You will need a classic transformer soldering iron, no less that 75W. I use this oldie one for 26 years:
    [​IMG] [​IMG]
    The prolonging of the soldering iron tip is necessary - additional resistance stop overheating the soldering tip too much.

    Some resin is need too:
    [​IMG]

    And a little bit of tin:
    [​IMG]

    And tin suction tool:
    [​IMG]

    ...and of course replacement caps and something with bad caps. In this case I choose very simple recap of Jaton GF2MX400 card. Of course this card is phased out and you will probably not made and 3DMark world record with it, recapped or not, but for testing or normal office use it is perfect. Thanks to it's passive heatsink and small size it is preferred graphic card, where you need just one to be. I use these cards in folding and testing machines ;)
    I do, on the top of that, use a little osciloscope 440 Scope Plus http://www.atcweb.com/tpi440.htm - http://postimg.org/image/qc1qqciol/ ;)

    So, let's first take a look at the card itself:
    [​IMG]
    As you can see, we gonna need:
    1x 1000uF 6.3V d8 Samxon GC
    4x 470uF 6.3V d6.3 Samxon GD
    3x 10uF 25V d4 Samxon ZS

    Let's take a look at the original caps...
    [​IMG]
    ...well, it is obvious they gotta go. Asiacon is the same as Evercon and this is the same cr*p as G-Luxon... :mad:

    Step first - desolder with the soldering iron the caps:
    [​IMG]
    Every time before use the soldering iron, dip it to the resin to protect against oxidation not only the contacts, but the actual soldering iron how wire tip. Result did not look ver pretty, but caps are gone now :D The white or shaded (or other way highlighted) holes are typically for the negative cap polarity wires. Of course you gotta stay alert for exceptions and crazy designs, witch can swap the polarity! Sometimes it is better first take a picture of the card to have proof on how it looked before... ;)

    Now come the hardest step - suck off tin from at least one of the holes. Choose the one that is isolated from the rest of the PCB. This way you heat up most only small piece of tin and PCB and hence you should be able to suck the tin off easily.
    [​IMG]
    Result - one hole is free.

    Now take the replacement cap - take care about the polarization (on some cards, such as Gigabyte FX5200/FX5600XT, it is contrariwise!). Caps has one longer leg, that is the positive wire. If you have free the positive hole, you are good to go. Insert the longer positive wire inside and the negative adjust to be pressing exactly against the tin in the not free yet hole. Apply only light pressure. If you need more pressure, shorten the wires, but leave the positive wire longer.
    [​IMG]

    From the bottom side heat up the tin in the negative hole and after a while (depends how big area of PCB you heating up) the cap nicely slide in place. Looks this way:
    [​IMG]
    If you got free the negative hole instead, then cut the positive wire of the cap in middle, so it get shorter that the negative wire and then work it out same way.
    Caps wires should be put thru to the end. Exception from this is only when you solder smaller or bigger spaced cap into holes that did not match. In that case - depends on how much the wires are getting dilate or closer - leave at least 3mm for the bend. Pressing too much in this case is very likely to damage almost any cap!

    When you have the cap in place as it should be, then cut off the remaining wires. Leave just about 1mm from them. And then with plenty of resin again solder them.
    [​IMG]
    Now it does not look pretty at all, right? :o Well, let's continue till we have every caps soldered first.

    Now will come the technical spirit in action. Using brush add the spirit in place where the resin is:
    [​IMG]
    And leave couple of seconds to take effect. You can see that the resin is breaking up and melting already. You can help big chunks get off by sharpened piece of hard wood - notably increasing the rate how the resin leave the PCB.

    Then first with rubber, also wetted in spirit, rub off the remains of it. Last small remaining of the resin is best to get off by brush, wetted in spirit again. The brush has to have reasonably tough strings.
    [​IMG]
    (image also show desoldered CE filters and coils replaced by pieces of wires)

    With careful clean up you can get professional looking soldering joints.
    [​IMG]

    And now you can only be delighted looking at how the new nice caps beautifully looking at the card.
    [​IMG]

    Whole look on the card with now exchanged caps.
    [​IMG]

    With such simple graphic card with minimum caps you can be done in like 10 minutes top. And with a little work you got the assurance it will not fail you for years and years. And now back with it to the computer ;)



    PS. sometimes happens - especially with small caps, where one can heat up with big soldering wire tip both holes - that it is possible solder the cap w/o actually sucking off the tin. Sometimes this is also the only one possibility, when the tin did not want get off and you did not want to damage the PCB... In this case simply cut the legs to be same and much shorter (so you can apply more pressure), align them right to booth holes, hold and from the bottom start heating and push... ;)
     
    Last edited: Oct 4, 2013
  2. OP
    OP
    trodas

    trodas Member

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    Trick with dental pick ;)

    The hardest part on recapping is cleaning the holes for new caps. So, there come a little trick...

    [​IMG]

    Yep, with this is the very same dental pick your dentist use to push on your teeths. You can buy it in medical supply shops, the only slight disadvantage is that the quality ones cost premium. But the vacuum tin sucking toy is not even recommended on BadCaps, because from heated PCB it easily can suck-off small traces, or by the back impact it tear them on the mobo. Sometimes it happen for me and certain low-quality mainboards (like JetWay V266B, Abit BX133 and so on) are very prone to this.

    So, at first we have holes after desoldered cap (or never soldered cap there) full of tin:

    [​IMG]


    So just attach the pick and reasonably push on it with one hand to stay in place (beware, it is very sharp, be carefull!):

    [​IMG]


    From the other side heat up the PCB with iron and soon the pick do thru the hole like hot knife thru butter and try to push it as far, as you manage with reasonably small force:

    [​IMG]


    Immidetelly after you reach the end, start wriggling with it to sides/up and down a bit, so it will not stuck to the tin or resin in the hole:

    [​IMG]


    Now the big metal chunk of this dental pick come to play - it disperse the heat perfectly, so in just a few seconds we have a free hole:

    [​IMG]


    Now let's repear that with the second hole, when we want to solder the cap inside easily (or he is on wrong place with bad access):

    [​IMG]


    Push a little and we are on the second side easily again:

    [​IMG]


    ...and now we have both holes free and perfect for soldering new cap in:

    [​IMG]


    As you can clearly see, this methos is easy, comfortable and fast. And the dental pick clean really well. Tin does not get attached on it at all and resin only very lightly. Cleaning with piece of old clothing and technical spirit is done in few seconds. The steel is very high quality, elastic a little and very hard to break. Almost impossible, I never managed it yet and I tried :) Comparing that to the nevereding cleaning of the vacuum tin suction tool... well, this is not comparable at all. Productivity in recapping go very much up using dental pick. Caps almost like jumping in the board ;) :D

    Sometimes it happens that in the holes remain too much tin, that create knob around the holes, where capacitor will be soldered. Such knobs that are on the top of the PCB are easy to tear off by nail or cut off by scalpel.

    Soldering was made by my 75W transformator solder, using lot's of resin. Pictures are not retouched at all and I did not even clean the board before taking the pictures. Board in question is Compaq Evo D310 one (MSI 6541 v1.0), exchange 10pcs of 1000uF 6.3V G-Luxon crap caps for 13pcs 1000uF 6.3V Samxon GC caps.
    Board works well :)
     
  3. the3coopers

    the3coopers Member

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    Nice guide.

    You forgot to show the most important step, which is how to apply the soldering iron to the leads.

    Any newbie that needs to read a guide (on something as simple as this) will also need guide to how to USE a soldering iron.

    For example, many people thing that you much apply heat to the component lead (leg), which of course does not work.

    ---

    It's MUCH easier to use Solder Wick for removing solder

    WATCH > http://www.youtube.com/watch?v=htrcZuK_ZsY

    I also use a pick sometimes, but only needed for very tight holes. It is EXTREMELY easy to damage through-hole plating with things like picks, so it should only be used as a last resort.

    Since solder wick will remove all the solder anyway, there is almost never any need for a pick. Get solder wick cheap from DealExtreme or similar - the Goot brand is pretty good (also available at local electronics stores, but more expensive)..

    ---

    Interesting that you use the word "tin" when you are using solder (which is only an alloy that includes tin). We call that stuff "solder" here in Australia. Also you are using separate flux, whilst in Australia most solder is Rosin-cored and doesn't need flux (the flus is inbuilt inside the solder wire).

    Separate flux is very "old-school" and also not very good for hobbyists because the flux gets old and does not work very well. Much easier to use rosin cored solder, and it's easier and less expensive to buy in small quantities here in Australia.

    What is this mysterious "technical spirit" that you refer to?

    Also, are you only removing the flux/rosin for appearance? I cannot recall anyone saying that leaving it there is "bad"... in fact it provides prtection for the PCB surrounding the newly heated varnish (on the PCB) that may have been degraded by the fresh joint.
     
    Last edited: Oct 4, 2013
  4. OP
    OP
    trodas

    trodas Member

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    the3coopers - thanks for the suggestions! I will try to improve the tutorial as much, as I can.

    I don't think that people, who cannot solder well, should even think about recapping. This is not the targeted audience ;)

    Very interesting video. I never used this in my life, but it looks like a viable alternative. Dunno if this is "much easier", as nothing can beat just pressing the dental pick into the hole and gently heating it up from bottom and - voila! - it go thru like hot knife thru butter.

    Then I was probably lucky, that this never happend to me - yet :)

    Well, I'm not english native, so I better correct that mistake. Yes, it is a alloy, but mostly composed of tin... and some lead. Except lead-free solders...

    Exactly that I using also. However it still need a good deal of resin, when you work with the 100W transformer soldering iron. So I never count the resin into the solder wire in the first place...

    Also I'm probably lucky, since that never happen to me. Resin works great in protecting the soldered parts for me...

    Again language barrier hit there :) The czech word "líh" is translated be every dictionary as "spirit" ... but since this spirit is not for drinking and the "líh" was sold as "technical", hence I created this "mysterious" naming.
    Looks like I get it wrong. So, what is the correct name?
    It definitively melts resin :)

    Yes, it looks way too ughly :)

    I would be more concerned about the protection of the joint itself. But for that, people melt resin in acetone and "paint" the back of the PCB with it. It is transparent and protect things well.
    But for the planed lifetime of about 20 years and good enviroment (home) these things will stay, then I think I did not need to do that.

    But it might be interesting to add this paint in the future. Yet the joints did not corrode much - or at all, so... I see a little what can be gained there.
     
  5. TERRA Operative

    TERRA Operative Member

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    If I might make a suggestion.

    Those Samxon caps you installed aren't much better than the ones you pulled out (if at all).
    I would recommend Rubycon, Nichicon, Panasonic. I like to use Rubycon ZL series (ZLK are my favourite).

    Also, a temperature controlled solder station is a good thing to use if available to prevent the possibility of lifted tracks.

    PS. I prefer a solder sucker over wick. Even better is the Hakko desolder station at work. :leet:



    The spirits you are talking about is probably white spirit, methylated spirits or isopropyl alcohol, one or the other... It's a good idea to remove the rosin, as it can retain moisture and cause corrosion issues (not to mention capacitive issues with sensitive circuits).
     
    Last edited: Oct 4, 2013
  6. c_hegge

    c_hegge Member

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    ^
    Samxon GD, GC and RS series are fine. Up there with Japanese caps. It's some of the other slightly higher ESR seires (GL, GF, GK), that they have trouble with. As for Rubycon, ZL series are too high ESR for use in this application. The correct series would be MBZ or MCZ. Better yet, poly-mod it.

    To remove the flux/resin/rosin, I use this stuff (http://australia.rs-online.com/web/p/flux-removers/4803320/). Isopropyl alcohol also works very well, though.
     
    Last edited: Oct 4, 2013
  7. the3coopers

    the3coopers Member

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    Coops walks into electronics shop
    Person behind counter asks "What can I help you with?".
    Coops points to the item on the shelf and replies "your Aerosol Flux-Off"
    Coops gets punched in the face :lol:
     
  8. OP
    OP
    trodas

    trodas Member

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    About the wrongly suggested "low quality" of Samxon caps - nothing could be farer from the truth. If you deal with fakes, then yes. I got mine as real-deal from Hong Kong and they are probably the best electrolytes ever made. Their GD and GC series are outstanding and their GA series are the best that exist. Ever. Period.

    Only one cap could par-to-par with specs, and that is Nichicon HZ. But if you get the HZ into your hands and compare them (3300uF 6.3V both), then you realize that Samxon do it sturdy, they used even slightly thicker wires to pass the specced currenty, while the Nichicon is as normal cap and Nichicons are prone to being light-build... Not thicker wires, nothing special.

    I'm guy, who get from their first testing GA line or 30 caps 6 or 9 of them, not remember exactly... but ther are (snip the identification of the person who provided this) the measurments:

    [​IMG]

    Nothing, remember NOTHING on Earth could come close to these Samxon electrolyte caps.
    If you deal with fake bad caps - your problem. Nothing is wrong with Samxon. If I can get more of these, I will. But Man Yue stoped making them :(

    Another good example - back in 2008 I recapped with Samxon caps friend GFX card 7300 GT ( http://forums.overclockers.com.au/showthread.php?t=1098065 ). Recently the card come back to my hands and surprise, it not only still works, but it show the quality of the Samxon caps by - overclocking. Default clocks 350/300 can just just upped to 588/376 ...!

    [​IMG]

    (need four MHz down to pass 3Dmark 2003, tough http://hwbot.org/submission/2441201_trodas_3dmark03_geforce_7300_gt_ddr2_8516_marks )
    [​IMG]

    So, who claims that Samxon caps are anything else that best caps ever, are just plainly wrong.
     
    Last edited: Oct 26, 2013
  9. Smoke87

    Smoke87 Member

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  10. c_hegge

    c_hegge Member

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    ^
    They are solid polymer caps. I wouldn't worry about them too much.

    Trodas is in the Czech Republic, though, so shipping it to him could be rather expensive from here. I'd probably charge $40 or so to do a card like that.
     
  11. OP
    OP
    trodas

    trodas Member

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    Smoke87 -
    Not to worry, I can't identify them either. That is laughably small picture. I would QUESS that they are Samxon (presumably fake?) or Elite (these nicely exploding in Asus PK5 line or mainboards) caps on the output and the blue are probably Chemicon input polymers.

    I would replace them by Nichicon LE polymers, that have far better specs and if and when possible, add something ceramic/POSPAP (tantal-polymer) on back of the main chip.

    That maybe anything. I did not like the shade, but the picture is too tiny to anyone can say anything. Look, I need that picture:
    http://trodas.wz.cz/kondiky/cap_images/1209896696.jpg
    Or this way:
    http://trodas.wz.cz/kondiky/cap_images/1209896687.jpg
    (both are true Samxon URL polymers right into my hands)

    First check the postage price. Datsun 1600 send me 4 screws and 1 CPU and it cost 3.5$ AU. But that is too small package. Also if you want just turn-around recap, then you better include the caps too, because my contact in USA is at least unreliable, I often have to wait months for caps, and you probably not want to wait months for simple recap, that could be done in turn-around session.

    It is also good to mention that overclock depends greatly on the quality of YOUR PSU (mine using all good caps, you can't buy PSU like that) and the quality of your chip. If your chip is a bad overclocker, then nothing on Earth could help. Of course few MHz is almost guaranted, but I would quess that this is not what you are hoping for, right?

    As the caps, to determine best replacements I need to know the diameter of them and for the 16V input ones also to measure, if a d10 cap fit there, to get the bigger capacity the better + how the legs space are, to be sure we can push a d10 there.
    Also the height could be a issue - Nichicon LE have a 6300mA and then 6600mA ripple current caps, while the later is 12mm in height. What is the space there?
    http://www.digikey.com/product-detail/en/PLE0E821MDO1/493-3059-ND/1662445 - 12mm
    http://www.digikey.com/product-search/en?vendor=0&keywords=493-3058-ND - 9mm

    The two light purple caps on the left top side of the card are probably Sanyo Oscons, that is a good caps. Not best, but more that good enought, if they are genuine.

    As I showed there:
    http://forums.overclockers.com.au/showthread.php?t=1098608
    ...there is a HUGE difference between what the company show to you (and to the reviewers) and what the company ship to you.

    If you are serious, then determine the weight of the package (presumably card w/o the heatsink - but pack it well, so it survive!) and I ask on post, how much that to Australia will cost.

    As c_hegge hints, it maybe will be a much easier if you hook up some guy nearby. I dubt that I'm the only one skilled with soldering iron :p
     
  12. trackhappy

    trackhappy Member

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    Why resin? I've never used or needed it before.

    But it's a nice guide, sticky-worthy even.

    Great work :thumbup:
     
  13. Smoke87

    Smoke87 Member

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    Thanks for your advice mate, I will take a closer look at the card particularly to determine whether replacement caps will fit under the heat shroud!! Get back to you next week.
     
  14. c_hegge

    c_hegge Member

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    I've said it before, and I'll say it again. Those ASUS junk caps are NOT Elite brand. They are Apaq.

    I doubt the caps on the card are Apaqs. They are usually either black or red in colour, not pink. My guess is either Samxon, or maybe Enesol, but there are a lot of others that use pink markings too.
     
  15. DrFrag

    DrFrag Member

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    Good skill to have. Two of my screens have been fixed by replacing the caps. One of them I pulled out of a wheelie bin after a computer shop threw it away. $10 of caps later and I have a working LCD.

    I didn't use resin or anything fancy, just a regular soldering iron, solder, and suction solder remover from JayCar. Got my replacement caps from there too.
     
  16. Smoke87

    Smoke87 Member

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    Man I have a sweet samsung LCD that fails to power up, I swear its a capacitor issue but no whine or bulging on them :(
     
  17. DrFrag

    DrFrag Member

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    All the busted-cap LCDs I've seen had a working power LED but a blank screen. If the power LED doesn't even come on then it might be something else.
     
  18. c_hegge

    c_hegge Member

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    My parents' monitor, my grandparents' monitor and our workbench monitor at work (all Samsung 226BWs) were given to me for free dead with bad caps. They work fine after recapping them, and if you do it with good quality Japanese caps, the fault will probably never re-occur.
     
  19. OP
    OP
    trodas

    trodas Member

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    This is not uncommon. Many bad capacitors dry-in, so there is nothig visually wrong with them. But just desolder them and hook up on measuring tool and - voila! - theis specs are way off or almost nonexistant...

    So once again, it is not really determining, how the capacitor looks. If it is a known bad cap, then I would replace it even in new stuff. If it is unknown brand, then I would be inclined to replace it also, sooner or later. But not too late, before bad things can happen...

    Well, I go by what the NewBeetle used from Xtremesystems forum reported. Maybe different Asus batches used different caps, or he is just mistaken. All in all, it does matter very little.
    The flaw is to have only two of these on the Vcore input filter for overclocking board. For a totally low-end crap I would complain, but for overclocking board... there is no words for it.

    The case in point is, that these are not KNOWN good caps and they are way, way (okay, several magnitudes of a way) underpowered. The simple Sapphire 7970 OC board have SEVEN of these input filtering caps...!

    While it can be argued, that maybe not even good caps stand a chance there, then definitively they should not explode with such force to damage the ceiling ;) BTW, after exchange for simple Sanyo (elyte!) cap the board was working again and was ever overclockable.
    That somewhat prove my point, that the input caps are maybe better of higher capacitance that terribly high ESR... hence a electrolyte caps might do better / compareble job there. The best way would be probably combine these two - polymers for the current spikes, as they can provide plenty of current and elytes for the capacitance. So, slapping a 1500uF Nichicon HZ 16V cap on each of the 12V rail (and if 5V is used too, then a 3300uF Nichicon HZ 6.3V too) on the Sapphire 7970 OC board will make the card looks weird (perhaps even interfere with ram slots, depend on mainboard - and I considering these caps to be lying on the back of the PCB of the card), but it definitively could help also. The same way NewBeetle user helped his Asus.

    All it IMHO matter is to get the voltage regulators as well supported, as possible. They LOVE this :p :thumbup:
     
  20. c_hegge

    c_hegge Member

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    The latter. See http://www.apaq.com.tw/eng_company.asp. Note the logo on the caps.

    That, I agree with. It's disappo9inting to see that Gigabyte are also starting to use Apaq caps on their low end boards too. All of the B85 boards have at least some Apaqs there. If you want all Japanese caps, you have to go with at least H77.
     

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