Introduction: Imac G5 DIY Capacitors Repair

Picture of Imac G5 DIY Capacitors Repair

There are probably enough DIY manuals on how to replace those bad capacitors
in the G5 imac model...
If not then this will maybe help..

If you're Imac G5 is suffering from power problems (not turning on, standby issues, video problems and scrambled pictures. Maybe its time to check those capacitors on the motherboard)

Checking those caps is easy and takes 2 minutes: Follow step 1 and 2, and step 7 and 9 to know what to look for...

Step 1: The Imac...

Picture of The Imac...

The Imac G5 was was plagued with the Capcitor problems, Apple started a special warranty program to repair all those Imac's. That program has bin terminated, but I have seen the same problem with the timecapsule as well. Today there are not that many people that want to repair there imac G5 but for those, here we go...

Our victim: A "left to die" Imac G5 17." We are going to save him in a Saturday afternoon.
Here are some things we need to help him:

A LOT of space...  We need to store all his parts temporary and we have to work on its motherboard.
It also keeps things organized.

Tools: These are the tools that I used:
soldering iron, screwdrivers, torx screwdrivers, anit static band, pliers, thermal compound, and replacement capictors.
Experience: Please have some, Its not difficult, but I think some is defiantly required.

Safety warning: Always unplug the power!! Even when the power is unplugged some capacitors will remain there power! In the new Imac models these power supply units on the bottom are open, and you WILL get a high voltage shock from it!! This is not the case here but be advised, if you see something and you have no idea, just stop and ask someone who does knows!

Capacitors: The ones that we are going to replace are bulging and could spit out electrolytic fluid or residue. (In fact, mine did when pulling them out...) Clean of this stuff from youre hands and the motherboard immediately!!! And wear safety goggles, the old capcitors are under heavy pressure, if they burst right in your face then... Well, youre not becoming any more attractive from it...

Step 2: Get Started...

Picture of Get Started...

Open the Imac:
Open your imac by turning the three screws on the bottom al the way tho the left. These screw wont come out but they will unlock the back. you can tilt the back off by lifting it up at its foot.

Here is a basic overview of the imac, now you know what to exspect.

We will start at the cd-drive:
Just undo the the three screws around the drive. When your done pull the drive out by
the white label on the right. I have also removed the memory already, I dont think I have to
tell you how that is being done... Come on, you have to be a geek to follow this instruct right??  RIGHT???

Step 3: Airport, Fan Board and Harddrive...

Picture of Airport, Fan Board and Harddrive...

Airport and dail-up modem:
Pull out the antenna from the airport, you must do the same thing for the dail-up modem.
What the....  who uses these things anyway?
Pull the airport out, then the grey plastic bracket. After that, pull out the dail-up modem.

Fan board
Two screws, I say no more...

Remove the sata and power supply cable on the left of the drive, then undo the three screws around the drive. Dont forget to unplug the temperature control cable that leads to the motherboard. Keep the cable with the drive to make it easy later on...

Step 4: Power Supply and Inverter...

Picture of Power Supply and Inverter...

Power supply and cable:
Turn the three screws on top of the power supply to the left.
Watch out: the screws in the power supply cannot be removed!!

Next undo the little hook on the power plug and insert a flat screwdriver like in the photo...
Turn the screwdriver in the two holes to force the plug backwards.  At some point the plug let's go of the socket and you can grap it and pull it all the way back. (this can be a bit tricky)

Next you can pull out the power supply likes this:
Oh, and dont forget to turn back the slot screw back into the closed position. (to the right) This will help make space to remove the power supply.

Left inverter unit:
One screw in the middle, pop up the grey inverter and remove the two cables, leading away from it.

Step 5:

Picture of

Cables and plugs:
Just to make sure, make a picture like I did of all the cables connected to the motherboard.
They are made not to fit in a another socket then they where designed for. (still, just make those pictures, its going to save time and headeaks.)

Tip: dont pull on the cables or wires, I must insist: Use the freaking plug to pull it out.
Many plugs where destroyed by rough handeling or jurking on till it broke.
(I broke some to in the past to)

Remove any cables that are lying around in the case...

Step 6: Removing the Motherbord..

Picture of Removing the Motherbord..

Alright, here comes the big job, remove the following screws:

From left to right or see photo for details:

- On the left in the upper and bottom corner, two gold color screws.
- Between the powerplug and bad capacitors, one silver.
- Between the big fan and the video out plug, one silver.
- Between the rowes of capacitors on the bottom, one silver
- Grey air output ontop of the "G5" logo, remove the left and the right one.
- Between the "G5" air tunnel and the memory banks, two silvers...
- On the top right and bottom, one silver and one gold.

Now remove the motherboard like so:
Grab on the cooling block and the connections and pull it out like shown.

Step 7: Soldering and Replacing

Picture of Soldering and Replacing

Put a static free mat on the table and make sure you connected to it as well.
Then mark the capacitors on the back that needs to be replaced. That way you make sure that you dont head up or remove the wrong parts.

Capacitors that needs to be replaced are being identifed by:
top, sides and bottom bulging or leaking electrolytic fluid on the top.

I wanted to use this koper stuff, when heated up it sucks up the tin from the motherboard. but the connections are so small that it didnt work. The best to do this is to head up the tin connection point(s) of the capacitor and then pull the capacitor out of the board:

Practice on a old circuit board first, to study the technique and make it your own:
Heat up one leg, (the left) and pull the capacitor to the right. Heat up the right leg, and pull the capacitor to the left. working your way up, at some point the legs are free.
(Take your time and give the motherboard enough time to cool down.)

My problems: Well, I messed up, big time. (well, Iam human two right? (So I have bin told.) 
Two legs of two capacitors are stuck in the motherboard. Luckily for me apple made a spare place for a extra capacitor. So I solderd one into place right there. Unfortunately I was forced to solder two wires to another capacitor witch had to be placed somewhere else. With some tape I insulated it an mounted it somewhere else on the board. Not really a good solution but it works.

About the capacitors: The replacement capacitors I used where from a old power supply, I didnt buy new ones. In this case it doesnt matter because there new function on the motherboard was exactly the same. I didnt have to buy very special ones, but if needed you can buy them of the web very cheap.
But please do use the same type and ratings and watch the polarity!!!

More information from Asmodeo: (many thanks to him)
I've changed capacitors in PC motherboards a lot  of times, and the tricky part is desoldering the old ones. I have a method:  Use a 60Watts soldering iron, applied to BOTH legs of a given capacitor at the same time. Let It heat for 10 seconds.(It´s a bad capacitor...You can't ruin It!).
Then, SLOWLY, pull the capacitor out of the board while applying heath.
To open the pad orifice where the capacitor lead was , use the copper "tail" is a hard way, but It is worth the effort. If the orifice doesn't clean at your satisfaction, then use a drill bit of the right size (0,5 mm is ok ) ..but use it BY HAND..make a handle for it with some isolating tape!

One thing I do not agree with You is: "put same rate capacitors"
The "capacitor maladie" is due to capacitors that are rated up to 85°C of temperature.
I  always use as a replacement capacitors of the same rating in microfarads (uf) AND volts , but capable to withstand 105°C  of temperature.
The difference in price is negligible.

Step 8: Put It Back Together

Picture of Put It Back Together

Before placing back the motherboard you will have to clean the cooling residue on the processor. This also counts for the cooling platform. Use pure alcohol and a cleaning tissues to remove that nasty stuff. Then put the same amound like shown on the photo here on the proccesor.
Keep it like this!!! It will spread as soon as you place back the motherboard into the mac.

Watch out for this little "light tunnel" place it back first in the proper position before you place back the motherboard. This is important, or the led indicator on the front will not show correctly.
And keep those cables in that aera clear, then place back to motherboard as you toke it out.

Now you should follow this instructable in reverse, but this time mount everthing back into place.
That should be easyer, ones youre done go to the nex step:

Watch out for:
-Do not force screws!! If they dont fit or do not go in well, you probably using the wrong screw.
Check this instuct again.
-Check if all cables are there, some cables can be stuck under the motherboard, then
you have to take it apart again.
Keep cables clear from everthing and place them correctly.
Airport bracket:  Dont forget to pull he antenna trough it first , other wise you will have to take it apart again.
-If youre having trouble with the cables on top, just remove the big fan on top. It will make room for you to place those cables back.

Step 9: Testing the Unit...

Picture of Testing the Unit...

Here are some photo's from the nasty caps, they smell horrible. Now you know what to look out for.

Now we have to test it, watch and stand back when you plug in the powerplug.
When turned on the mac should start normal again like it did before. Keep an eye on those new caps, if you have replaced them correctly nothing should happen. If something does happen: Smoke, strange smell, fire, exploding caps, turn of the unit immediately!!  Check what went wrong and repair, and ask someone for help if necessary! (youre not alone at this)

Almost done...
When done testing: Place the lid back on the imac and turn all three screws to the right.
Congratulations, another beautiful Imac saved from the dump yard. He will be happy to serve you as your best friend for many years to come...


seacanyon (author)2015-11-08

You can drills holes in pc board to replace broken legs.

HugoMaqueroEspañol (author)2014-03-28

Can someone send me a link with the capacitors on or ebay?

I dont know which buy, so i need help.

Noddes (author)2012-04-04

Hi Has anyone changed caps to cure a video fault ie machine operates fine but monitor shows predominately green /yellow odd time will operate ok but soon slips back to this mode. I am willing to make a full replacement of caps as per EWOUT 's instructions but don't want to strip it down if it does not work. The caps show no sign of bulging or leaking. Thanks for your replie(s)

ewout (author)Noddes2012-04-04

Well, if you did see the top bulging or leaking electrolytic fluid on those caps then it would be easy to tell if it would work, if not then the only way to know for sure is to take them out and replace them. For those who cannot measure caps its the (only) cheapest way to tell... you have to get your hands dirty....

ashiekh (author)2012-02-06

Radio-Shack make a very nice soldering iron that has a hollow tip, and this makes it much easier to heat the leads all round, and it is probably best to replace all the capacitors at the same time, as those that look sound are probably soon to fail anyway.

The power supply probably needs recapping at the same time.

dcain1 (author)2011-10-25

I need my PSU fixed but am fearful to do it as i have no experience. could i pay you to fix my unit? dancain @

ewout (author)2011-08-09

I want to thank you guys for still leaving comments even after one year...
Iam happy to see that a lot of people are using the instruct to repair there broken imac's, giving them a second live.

Many thanks to you all...

captain3d (author)2011-08-07

I managed to re cap an imac G5 today using this guide and it is now up and running installing a new system. Made me happy.

My old, little soldering iron was not up to the task as it could not deliver enough heat to release the old caps. I bought a 140 watt solder gun and still had to hold it there for 10 seconds to get them out, but it worked.

I heated the the blocked holes and pushed on the new caps and slide them in one leg at a time until they were seated. Then again gave them a good blast and another drop of solder with the solder gun.

The one thing I missed was refitting the left grey piece (inverter unit). I had connected the two cables but missed the four pin socket as I had not seen that on the dismantle. Once refitted correctly the machine seems to be up and running.


kallisti5 (author)2011-07-18

To be honest, you can use capacitors of a different voltage in a pinch, as *long* as the new ones have a higher voltage tolerance then the old ones... your biggest problem from this will be the physical size difference.

You however *MUST* use caps of the same capacitance (eg 1800uf == 1800uf)

kallisti5 (author)2011-07-18

Great guide, I am going through this process at the moment as well.

Keep in mind your PSU may also have quite a few popped caps, if you are more skilled I would check it out as well.

For the PSU, gently scrape the gray epoxy away from the bused caps without scratching or bending the coils.

Data643 (author)2011-05-27

Wow. You won't believe this. My friend found one of these iMacs in a dumpster last week. He couldn't get it to work (boots with idle screen) so he gave it to me. I think that the caps are faulty. I read on iFixit that there was a stream of bad caps around the time that these iMacs were produced. Anyway, i'll give your method a shot.

Agent24 (author)2011-05-18

Yes you must use 105°C rated capacitors but not ANY capacitors.

They need to be good brand, Rubycon, Nichicon, Panasonic, Sanyo etc and also must be the correct series to ensure they have correct ESR and Ripple current rating (Check the datasheets of the old and new capacitors)

Also, do NOT use a drill to clear VIAs, you can very easily destroy the plating and ruin the board.

If you must use something, the BLUNT end of the drill, while applying heat to the joint and push the solder out.

Do NOT drill using the sharp end while the solder is cold.

techwreck (author)2010-08-07

goo gone, or rubbing alcohol does the job. if you want to polish it. Use a 1:1 mixture of rubbing alcohol and lemon juice. works all the time.

Kasm279 (author)2010-07-11

You might want to re-word this "Dont get in youre eyes or wear safety goggles!!!" to something like "So you don't get it in your eyes, wear goggles!" It sounds like you are saying either don't get it in your eyes or don't wear goggles o.O

ewout (author)Kasm2792010-07-11

There is always room for improvement, I made some changes for you... Hope you like them.. I must point out that English is not my mother language but I try my best...

gspiderman (author)2010-02-25

Can you recommend a good place to buy the kit?

ewout (author)gspiderman2010-02-27


But iam not sure what to do with 25 caps?

Same thing here:

I think you should order those things separately and not as a kit, its probably the most cheapest way to do it. Just take same values and if your budget permits it: Take caps that can take a bit of heat to prevent this from happening again!!

Asmodeo (author)2010-01-04

Really nice instructable!!!
It gave us the opportunity to see a "naked" G5 As well !!!

I've changed capacitors in PC motherboards a lot  of times, and the tricky part is desoldering the old ones.
I have a method:  Use a 60Watts soldering iron, applied to BOTH legs of a given capacitor at the same time.
Let It heat for 10 seconds.(It´s a bad capacitor...You can't ruin It!).
Then, SLOWLY, pull the capacitor out of the board while applying heath.
To open the pad orifice where the capacitor lead was , use the copper "tail" is a hard way, but It is worth the effort.
If the orifice doesn't clean at your satisfaction, then use a drill bit of the right size (0,5 mm is ok ) ..but use it BY HAND..make a handle for it with some isolating tape!

One thing I do not agree with You is: "put same rate capacitors"
The "capacitor maladie" is due to capacitors that are rated up to 85°C of temperature.
I  always use as a replacement capacitors of the same rating in microfarads (uf) AND volts , but capable to withstand 105°C  of temperature.
The difference in price is negligible.

Thanks again for the photos.

milsorgen (author)Asmodeo2010-01-06

I'd be extremely careful using 60 watts for 10 secs.

Asmodeo (author)milsorgen2010-01-07

Don't worry.
I've used it for almost a minute and no pun for the traces of the motherboard.
You must realize that you are trying to unsolder a BAD capacitor (You can't ruin It MORE) and It's soldered onto the positive and negative huge planes of the power supplies....It's A LOT of copper that will dissipate the heat and , if You use less than 60W this will be a real problem....You risk of pulling a capacitor's leg that is yet well attached to the internal pass-trough-holes copper due to a "cool" soldering tip. Bad thing, I prevent You...
I have, once , used a 100W soldering iron (from a friend) and...well.....each damaged capacitor was out of the board in less than 5 seconds!!
Last sunday, I used a "solder sucking" device (I don't know how It's called in english), along with the 60W soldering gun....I was able to "unclog" the orifices in a matter of seconds.
I used a new approach to hold the mother board:
I made a "vise" with two 10inch "L" shaped plastics, almost 10 inches long, too, attached to my table with grips, and sandwiched between them the motherboard with two pieces of foam.
The board remains vertical, firmly held by the jig, and then You can use both hands, one for the soldering gun, and the other to pull softly the capacitors out, or to use the "solder sucking" device", one from each side of the board....I think I will make a permanent jig for that!!!

Nice year for everybody!

milsorgen (author)Asmodeo2010-01-07

Yeah I was just thinking of that all that heat near the PCB, I've been in some tight spots and burnt some pcbs with less. But I'm going to try and get some working caps off a video card later so I'm definatly gonna try some higher heat levels after reading this, only got 40 watts to work with but we'll see.

And that solder sucking device, I know them as desoldering bulb or pump depending on the type. But in a pinch you can also make your own solder braid  with some copper wire and flux to wick away old solder.

Anyways good luck to you Asmodeo!

ewout (author)Asmodeo2010-01-04

Thank you for your comments Asmodeo, If you don't mind I have pasted your info into step 7. Your right about  using a 60Watts soldering iron, Unfortunately I don't have one right here. And what I didn't test or confirm, I dont put here.

I agree with you about using higher temperature caps, because that is one of the reasons why we are replacing those caps in the first place.

Asmodeo (author)ewout2010-01-04

You're wellcome, ewout !!

milsorgen (author)2010-01-06

 lol glad apple users get to experience the joys same as us pc users

though i havent run into this issue since i was running socket 7s

dogboy12457 (author)2010-01-04

Thank you very much for this Instructable. My IMac at home broke same problem. I have had this happen once before. The guys at the shop looked at it and said it was going to cost 600$-700$. I figured it was going to brake again so i should just get a new one. Found this and fixed it. I didnt even think about doing it myself. you saved me money. It also happened to my uncle. He gave it to me. been lying around in my basement. I am going to fix his computer too. So I will have two IMacs thanks to you.

Again thank you.

ewout (author)dogboy124572010-01-05

Your welcome Dogboy...  Your excally the reason why I made this instructable.
Good luck repairing your Imac(s)...

ewout (author)2010-01-04

I have updated the instructable with answers from your questions. And made things a bit more clear. Thanks for your comments...

omnibot (author)2010-01-04

Great instructable.
The capacitor plague is a source of frustration and wealth to us all ;) I personally ow my flatscreen to this disease and a dead flatscreen is just as easy as with the iMac.

hemmikarl (author)2010-01-03

GREAT instructions on how to replace these capacitors.
although i don't need them many other migth need them

lemonie (author)2010-01-03

This is very well shown, how do you identify the cap's that need to be replaced?
(some dodgy-spelling, might benefit from a re-read?)


hemmikarl (author)lemonie2010-01-03

with electrolytic capacitors its usually the top bulging or leaking electrolytic fluid
on the other hand ceramic and polyester capacitors is not easy at all to identify whaich are broken

DanAdamKOF (author)lemonie2010-01-03

It's usually rather obvious, they'll be leaking the electrolytic fluid that's normally inside, or bulging.

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