Badcaps.net Forum
Go Back   Badcaps Forums > Welcome to the Badcaps.net Tech Forum! > Frequently Asked Questions (No Posting)
Register FAQ Calendar Search Today's Posts Mark Forums Read

 
Thread Tools Display Modes
Old 02-28-2005, 12:48 PM   #1
willawake
Super Modulator
 
willawake's Avatar
 
Join Date: Nov 2003
City & State: Αθήνα
Posts: 8,006
Default The Recapping FAQ

Here is the recapping FAQ.

Last edited by willawake; 06-04-2006 at 02:15 PM..
willawake is offline   Reply With Quote
Old 02-28-2005, 01:09 PM   #2
willawake
Super Modulator
 
willawake's Avatar
 
Join Date: Nov 2003
City & State: Αθήνα
Posts: 8,006
Post

1. Consider whether the board is a candidate for repair.

Before you start work you should consider whether the board is going to be working after you replace the capacitors or whether it is going to need a lot more work and parts which you might not be capable of doing or finding.

1.1. Checklist for considering a board :

If your board meets any of the following criteria then it will probably not be a good candidate for recapping. Please post in the forums to ask for assistance/opinions.

- Component(s) on the board are looking burnt
- Component(s) on the board are detached or missing (even tiny smt components)
- An essential connector such as HSF clip, ram clip(s), ATX connector are damaged.
- Traces on the board are scratched

1.2. Learn the history of the board

It is good to know the history of the board. For instance if the board developed badcaps but was taken out of service early then it is a great candidate for recapping. If the board was left for a very long time and the caps have leaked all over the place then the discharge can probably be cleaned up nice. If the board is now dead having shut down one day then if there is nothing burnt some caps probably failed open and the board is still good for repair. If the board died and there was a burning smell or burnt items on the board then there is a possibility that some caps shorted and you should ask for opinion here before starting the recapping.

1.3. Testing the board - a Warning!

If you are given a board to troubleshoot which does not POST, it just blinks the led on the board and the fan twitches, you must be careful that the board is not in a condition which will damage the CPU that you use to test the board. There is a possibility that the VRM chip is damaged because a FET has shorted and therefore Vcore will be too high. The board will be a CPU killer. Better to test Vcore with a multimeter before you attach your CPU to troubleshoot the board. It is always a good idea to test unknown boards with your worst components anyway.

Last edited by willawake; 12-14-2005 at 01:48 AM..
willawake is offline   Reply With Quote
Old 02-28-2005, 01:24 PM   #3
willawake
Super Modulator
 
willawake's Avatar
 
Join Date: Nov 2003
City & State: Αθήνα
Posts: 8,006
Default

2. Practice First and Study the Guidelines

It is totally possible for you to repair your motherboard yourself but you must read all the info first and also practice before you start your first repair. Even if you have read all the info soldering and replacing caps takes some practice to do nice. It will be VERY satisfying to see your first recapping boot up but dissapointing if it looks sloppy or doesnt work because you did it wrong.

2.1 Get a trash motherboard

The best thing to do will be to get a trash motherboard and practice removing the caps from it. Learn how to do it gently and you will also learn if your soldering iron is going to be hot enough for the real job. It would be good also to get some of the cheapest caps and practice installing them on the trash board.

2.2 Learn what is a good solder joint

Learn what is a good solder joint from the following links and practice making one. We guarantee that this will be the most difficult part of the operation but with practice you will learn to do it well.

Elecraft Builder Resources (Click on Soldering Tutorial)
http://www.elecraft.com/Apps/K2info.html

Apogee Kits Downloads (Click on ApogeeKits Free Illustrated Guide to Electronics Soldering)
http://www.apogeekits.com/downloads.htm

The Basic Electronics Soldering & Desoldering Guide
http://www.epemag.wimborne.co.uk/solderfaq.htm

Last edited by willawake; 03-20-2006 at 02:06 AM..
willawake is offline   Reply With Quote
Old 02-28-2005, 01:45 PM   #4
willawake
Super Modulator
 
willawake's Avatar
 
Join Date: Nov 2003
City & State: Αθήνα
Posts: 8,006
Default

3. Plan the job before you begin

3.1. Check you have enough caps

The most important thing is to check that you have enough of the right values of caps to complete the job. When you are done you will be eager to see the board boot and you won't want to wait for another order of caps. Check the original caps on the board again to see if you had missed one or made a mistake with the values. It is very easy to do that.

3.2. Make a Diagram

Diagram of the board connectors

It is very good practice when removing a motherboard from the case for any kind of job to make a diagram of the case connector positions (Power Switch, Reset, HDD Led etc) also record the position of each coloured wire. Mark also the position of the primary/secondard IDE, floppy disk, recording the position of the red line on the cable. This makes it so much easier and then you dont have to go hunting for the manual of someones obscure board on the internet when you hooked it up wrong later. Or having to open the damn case again cos you had the hdd led backwards etc.

Diagram of the position of the caps

It is very important to make a diagram of the positions and values of the original capacitors on the board. Make sure that you note where the negative lead of each capacitor is on the diagram. The negative lead is marked on the capacitor with a stripe down the side. This stripe matches the white hemisphere around the hole for the negative lead on the board stencil. This diagram is a useful tool also for final checking before you power up the board. It is very important to record the position of the actual negative lead of the original capacitor because the board stencil may be wrong and you want to recheck with the diagram before you install a new capacitor incorrectly. Mark on the diagram the values of the original capacitors and also the values which you will replace each capacitor with if they are different. It is very useful to have this diagram handy during the recapping so you can concentrate on the soldering and not have to think too much or make a mistake.

3.3. Mark on the actual board the positions where caps were not installed.

Because of design changes and revisions there may be positions on the board stencil where capacitors were marked to be installed but were not. It is very important to mark on the board with a thin marker pen an X on these positions. It is not recommended to install caps in these positions unless you are following a tried and tested board mod. It is very easy to make a mistake and install caps in these wrong positions so it is nice to see the Xs marked on the board to remind you.

Last edited by willawake; 06-04-2006 at 12:09 PM..
willawake is offline   Reply With Quote
Old 02-28-2005, 02:09 PM   #5
willawake
Super Modulator
 
willawake's Avatar
 
Join Date: Nov 2003
City & State: Αθήνα
Posts: 8,006
Default

4. Prepare your workplace and the board

4.1 Get all your tools handy

the minimum you will need is the following. Get it all ready and close to hand. It is a pain when you have to get up and search for something during the job. Get your soldering iron heating up while you are preparing the area. You want to set the iron to 450oC and have it heating up for about 10mins before you begin.

- Soldering Station or Corded Soldering Iron (must be grounded! and at least 40w (60w is a good choice)


60w ERSA soldering station. Very important to have a wet sponge to clean the iron when working, whether you get a corded iron or station.


what you thought was good was useless. 40w is the absolute minimum for recapping. short "standard" chisel tips are recommended because they hold more heat

- Solder (60/40, 0.8mm is good)


solder 60/40 0.8mm

- Stainless Steel Sewing Needle or Stainless Steel Dental Pick (see later on in the FAQ)
- Desoldering Bulb (if you like)
- Lead Clippers (Fine Wire Cutters)


pro's kit lead clippers
- Board Holder
- Flux Cleaner Spray


Cramolin Flux-Off spray
- Q-Tips/Cotton Buds (normall used for cleaning your ears)
- Alcohol (95% or best 99-100%) for cleaning electrolyte from the board
- Antistatic Wrist Strap



anti-static wrist strap
For cleaning the lead holes you can use either only the needle/pick or use a desoldering bulb/desoldering braid/desoldering iron (your preference)

4.2 Get the capacitors ready

Especially if you are working with several values of capacitors it is good to have each value in seperate compartments of one of those plastic boxes with many compartments for organising screws and stuff. This prevents picking up the wrong value and installing it on the board. You can use one of the compartments to put the removed capacitors in.

4.3. Remove all components from the board.

It is pretty obvious but it will get said anyway. You must remove the HSF (CPU Heatsink/Fan), CPU, Ram, and all cards from the board before you start. When you are removing the HSF of a socket processor (non P4 etc) you should place a business card inbetween the bottom of the clip that you will put pressure on and the board. This is because it is quite easy to press too hard and damage the traces.

4.4. Clean the board

Clean the board of dust on both sides using canned air before you start work.

4.5. Get the board holder ready

An easy to find board holder is two wood clamps, the ones which you use to secure wood to the table for safe sawing. There is probably some in your garage. You can attach them to your work desk upside down and then the board fits in between the handles and the metal guides of the clamps. It is important to have the board secure for removing the caps. If you intend to work with the board between your knees or something, it is not recommended and you will probably burn yourself.

You will want the board holder to be at one side of your workspace and then you want a clear flat area to accommodate the board lying on the table for installing the new caps. Your soldering iron must be in easy reach of both areas and comfortable to work with.
Attached Images
File Type: jpg solder.jpg (120.3 KB, 5769 views)
File Type: jpg wrist.jpg (126.4 KB, 5672 views)
File Type: jpg fluxoff.jpg (88.9 KB, 5710 views)
File Type: jpg clippers.jpg (130.5 KB, 5708 views)
File Type: jpg station.jpg (83.1 KB, 5785 views)
File Type: jpg tips.jpg (105.0 KB, 5792 views)

Last edited by willawake; 06-04-2006 at 02:28 PM..
willawake is offline   Reply With Quote
Old 03-01-2005, 01:55 PM   #6
willawake
Super Modulator
 
willawake's Avatar
 
Join Date: Nov 2003
City & State: Αθήνα
Posts: 8,006
Default

5. [ Removing the Capacitors ]

5.1. Get your safety glasses on

When you are soldering you MUST wear safety glasses or your normal prescription glasses. A spatter of hot flux in your eye can injure you seriously.

5.2. Get your antistatic wrist strap on

You must wear an antistatic wrist strap when you are soldering or handling the board. Put it on the hand holding the iron. The best place to connect the wrist strap is to the back of a computer which is plugged in.

5.3. Get the board holder ready

The best way for removing capacitors is to put the board on the table with the rear facing up. Then add solder to several caps. Then put it into the board holder to remove the caps. Ideally with the front of the board facing you while you heat from the rear. Otherwise you can hold the board in your knees if you have no board holder.

5.4. Add solder to each lead at the back of the board.

It is very important to add a little bit of solder to the leads of the capacitor you are to remove, at the position where the lead meets the board. This will assist you in heating all the solder quickly and easily when you remove the capacitor.

So heat up one of the capacitors leads from the rear of the board so your iron is contacting the pad around the hole and the lead. Then apply a touch of solder to the solder already there. Do the same to the other lead.

It is fastest to do this to a row of capacitors and then concentrate on their removal process.


adding solder to the leads of the existing capacitors


solder added and ready for removal.

5.5. Remove the capacitor

In order to remove the capacitor, you will heat up one of the capacitors leads from the rear of the board so your iron is contacting the pad around the hole and the lead. Then you will wiggle and push the capacitor towards the other lead while still heating the solder with the iron. Then do the same with the other lead.

You will make your own technique here. Some people like to heat both leads and wiggle them out at the same time. Others like to alternately heat and wiggle each lead until the capacitor is free. Or even get one lead completely out and then work on the other.

It is important to find the best way that removes the capacitor with the least strain. You must make sure that all the solder is nice and hot and dont pull hard but wiggle the lead back and forth a little until it is coming free. If you pull too hard when the solder is not hot enough you can damage the foil of the lead port which runs through the board and makes the connection to the electrical traces. Dont worry just be gentle and you will not harm the board.


Removing the cap

5.6. Having Problems to remove the capacitor?

If you are having problems to remove the capacitor then maybe your iron is not hot enough. If it is a 60W then maybe you should try a different sized tip, perhaps the tip is too long and thin and not transferring enough heat from the iron's heater.

Dont forget that if you are working near big traces they suck up the heat from the iron making it difficult to work in that position.

The types of solder used appear to differ with each board manufacturer. Some are easy to heat up, others are not. Older boards are more difficult to work on. Most boards you will have no problem with if your iron is hot enough.

There are different techniques for working on difficult boards. Some like to heat the board with a hot air heat gun or work with hot air pencil. Others like to use large wattage soldering guns for stubborn solder pads. All of these require some experience and knowledge otherwise the board will get trashed.
Attached Images
File Type: jpg 01_addsolder.jpg (143.0 KB, 5599 views)
File Type: jpg 02_solderadded.jpg (130.4 KB, 5581 views)
File Type: jpg 03_removing.jpg (72.8 KB, 5574 views)

Last edited by willawake; 06-04-2006 at 02:18 PM..
willawake is offline   Reply With Quote
Old 08-21-2006, 04:56 PM   #7
solarvolt
New Member
 
solarvolt's Avatar
 
Join Date: Aug 2006
City & State: Kalifornia (but not a Socialist)
Posts: 3
Default Re: The Recapping FAQ

Have found it useful over the years to ALWAYS photo document boards as well as diagram; just often enough being able to refer to a series of clear BEFORE pics from various angles will reveal some element that hadn't been covered in a diagram. Thanks to all for these excellent articles! (doing Abit VL6 project prep)
__________________
"Men occasionally stumble over the truth, but most of them pick themselves up and hurry off as if nothing ever happened. " Sir Winston Churchill (1874 - 1965)
solarvolt is offline   Reply With Quote
Old 07-10-2007, 10:50 PM   #8
bgavin
Badcaps Veteran
 
Join Date: Jan 2007
City & State: Orangevale, CA
Posts: 1,354
Default Re: The Recapping FAQ

Many thanks to Willawake for the sticky FAQ. I followed it verbatim, and my first recap job was a complete success.

Notable points in the FAQ are the temperature points for removal and replacement. I found the pin method for clearing the board holes worked best for me. I used some of my wife's dress making pins with a ball end for easy pushing.

Key point: be sure to clear the holes using the 450C temp setting. Lower than this doesn't work well at all.

Key point: flow new solder on to every lead you are going to remove. The FAQ is dead-on with this one. Worked great.

I used a Hakko 936 12/P with the standard small chisel tip. Solder was Kester 60/40.
bgavin is offline   Reply With Quote
Old 07-29-2005, 12:25 PM   #9
crkhed
New Member
 
Join Date: Jul 2005
Posts: 1
Default Re: The Recapping FAQ

I see inside alot of Dell PC's and I have purchased boards, Intel and others, that have a line or what appears to be a sharpie marker on top of the caps on the board. I have alot of speculation as to what the marks are. I would really like to know. As a matter of fact, I did read the FAQ's and even looked at the "The Good Capacitors Photo Thread" and saw the 1st photo there has what appear to be a "green" mark on top of all the capicators. What's up?
crkhed is offline   Reply With Quote
Old 07-29-2005, 04:05 PM   #10
willawake
Super Modulator
 
willawake's Avatar
 
Join Date: Nov 2003
City & State: Αθήνα
Posts: 8,006
Default Re: The Recapping FAQ

many boards and graphics cards have the caps marked with a sharpie / marker pen. It is assumed that the caps have gone through a manual testing and are marked as approved for installation. Presumably their esr is tested but perhaps they are only tested as functional and not shorted. We do not know the nature of the tests.
__________________
capacitor lab yachtmati techmati
willawake is offline   Reply With Quote
Old 07-29-2005, 04:19 PM   #11
kc8adu
Super Moderator
 
kc8adu's Avatar
 
Join Date: Nov 2003
City & State: dayton ohio
My Country: U.S.A!
Line Voltage: 12vdc,120/240vac,480vac 3ph on my bench
I'm a: Professional Tech
Posts: 8,289
Default Re: The Recapping FAQ

i often see this too.
i do this with invisible ink that shows up under uv.
i mark boards i recap in several ways to id them.
kc8adu is offline   Reply With Quote
Old 01-09-2006, 11:05 PM   #12
davmax
Badcaps Veteran
 
davmax's Avatar
 
Join Date: Dec 2005
City & State: Perth Western Australia
Posts: 886
Smile Re: The Recapping FAQ

I would like to suggest that a magnifying glass be added to the equipment list. Preferably at x10 magnification. This is used to check the quality of work before powering up the board. The most important to check are the vias that are surrounded by a copper plane (often an earth plane). So that there is certainty of no bridging solder.

Better to check before causing a problem.
__________________
Gigabyte EP45-DS3L Ultra Reliable (Power saver)
Intel E8400 (3000Mhz) Bios temps. 4096Mb 800Mhz DDR2 Corsair XMS2 4-4-4-12
160Gb WD SATAII Server grade
Nvidia 8500GT 256Mb
160Gb WD eSATAII Server grade for backup.
Samsung 18x DVD writer
Pioneer 16x DVD writer + 6x Dual layer
33 way card reader
Windows XP Pro SP3
Thermaltake Matrix case with 430W Silent Power
17" Benq FP737s LCD monitor
HP Officejet Pro K5300 with refillable tanks
davmax is offline   Reply With Quote
Old 01-09-2006, 11:48 PM   #13
davmax
Badcaps Veteran
 
davmax's Avatar
 
Join Date: Dec 2005
City & State: Perth Western Australia
Posts: 886
Default Re: The Recapping FAQ

Some recap pictuers. I like the VRM layout of the 8RDA+ board. The output filter caps neatly close to the CPU. Pictures show the replacing of these caps with Rubicon MCZ, three replaced at a time. Photos are resized to 600 pixels. The focus is not always good, I need a small tripod.
Attached Images
File Type: jpg 2006-01-10 015_small.jpg (74.3 KB, 611 views)
File Type: jpg 2006-01-10 016_small.jpg (70.3 KB, 564 views)
File Type: jpg 2006-01-10 018_small.jpg (90.9 KB, 634 views)
File Type: jpg 2006-01-10 019_small.jpg (84.8 KB, 511 views)
File Type: jpg 2006-01-10 017_small.jpg (112.2 KB, 590 views)
davmax is offline   Reply With Quote
Old 01-10-2006, 02:43 AM   #14
davmax
Badcaps Veteran
 
davmax's Avatar
 
Join Date: Dec 2005
City & State: Perth Western Australia
Posts: 886
Default Re: The Recapping FAQ

A few useful recap tips.

1. When inserting the capacitor, hold it firmly against the motherboard and cut off both leads close to the surface (using a good, fine and sharp cutter) before soldering. This will enable the solder to flow over and down the cap leads making a neat finish as well. This in fact emulates the original soldering.
2. When soldering is complete it is important to clean off all soldering flux. With the flux removed it will be possible to inspect (with a magnifying glass) the critical vias surrounded by earth plane. Any stray fine solder can then be identified and removed. To remove the flux use a stiff brush(toothbrush) and some methylated spirits and then clean/dry up with a lint free rag.
davmax is offline   Reply With Quote
Old 04-04-2006, 08:39 AM   #15
Elitist
Senior Member
 
Join Date: Apr 2006
City & State: GB
Posts: 159
Default Re: The Recapping FAQ

crkhed:
The scribed marks in the top of caps are deliberate stress-relief markings so that when they explode they do so with less ferocity and in a semi-controlled manner. This is a standard technique in engineering. In hydrogen plant engineering the roofs are generally hinged! Upwards, that is....
Elitist is offline   Reply With Quote
Old 06-04-2006, 01:47 PM   #16
willawake
Super Modulator
 
willawake's Avatar
 
Join Date: Nov 2003
City & State: Αθήνα
Posts: 8,006
Default Re: The Recapping FAQ

i am updating with some pics as requested.
willawake is offline   Reply With Quote
Old 06-25-2006, 02:56 AM   #17
Elitist
Senior Member
 
Join Date: Apr 2006
City & State: GB
Posts: 159
Default Re: The Recapping FAQ

Beautiful!
You didn't include an hairdryer/electric paint stripper to warm the board before attacking it with a soldering iron. Also a useful implement for removing smc ics and memory chips!
Elitist is offline   Reply With Quote
Old 06-25-2006, 02:58 AM   #18
Elitist
Senior Member
 
Join Date: Apr 2006
City & State: GB
Posts: 159
Default Re: The Recapping FAQ

PS. Sometimes I use a fine drill bit in a hand chuck to clear the hole. Essential to use an undersize drill bit!

mod comment : this is not recommended. probably you will screw it up.

Last edited by willawake; 08-05-2006 at 03:28 PM..
Elitist is offline   Reply With Quote
Old 08-05-2006, 03:22 PM   #19
parttimebill
New Member
 
Join Date: Aug 2006
City & State: North Carolina
Posts: 15
Default Re: The Recapping FAQ

...some very good information... thanks... parttimebill
parttimebill is offline   Reply With Quote
Old 05-28-2008, 09:25 AM   #20
Scenic
o.O
 
Scenic's Avatar
 
Join Date: Sep 2007
City & State: Duisburg
My Country: Germany
Line Voltage: 230VAC 50Hz
Posts: 2,615
Default Re: The Recapping FAQ

upload the .pdf version at http://upload.wozzap.de (10MB Filesize limit ; not allowed file extensions are listed there) and post the link here. i will then upload it to my private webspace and post the link here.

edit: my private webspace is paid webspace... not some free hoster crap that could disappear without a warning
Scenic is offline   Reply With Quote
Reply

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump



Badcaps.net Technical Forums 2003 - 2019
Powered by vBulletin ®
Copyright ©2000 - 2019, Jelsoft Enterprises Ltd.
All times are GMT -6. The time now is 08:48 PM.
Did you find this forum helpful?