iMac G5 17" w/ iSight - Display / Fan issues

Hi there. There's a 17" iMac G5 17" with iSight running OSX 10.3 at my work. It used to have a slightly blurry display (as if the resolution was slightly off, even though it was set correctly). Yesterday, the computer stopped working properly. When booted, it takes about 15 seconds before you get the Apple logo, and immediately afterwards, the fans kick on quite loud, and finally, the screen goes black.

My employer has given the computer to me now. I'm curious if there are some troubleshooting steps you guys could recommend before I go down the route of attempting a capacitor replacement. I tried reseating the memory with the same problem. I imagine I should probably take some canned air to all the fans and check for bulging / leaking capacitors... just looking for any other pointers before I spend money and learn how to solder (I've soldered a few things but never on a motherboard).

Thanks!

Have you opened it up & cleaned it to make sure the heat issues aren't caused by built up dirt & fuzz?

- Nick

I opened it to take the hard drive out to wipe it out for my employer before taking it home. I quickly pulled the logic board out just for fun and there really isn't that much dust in there, but I will dust it when I get home. I figured I'd ask about any other steps I should take while it's open. I believe mine is the second generation model... the hard drive is located top-center as opposed to top-right as shown in most photos online. Additionally, there is only one RAM slot. I imagine I should dust it out, check for damaged capacitors, loosely reassemble the iMac and try to boot with the installation disk? (For the record, I had the same boot issues with the hard drive disconnect.)

Well...too bad you already cleaned it & are still having issues. I guess that means the issues are being caused by something else...less easy & more expensive to fix.

- Nick

Oh no, I haven't cleaned it yet. What I meant is that I pulled out the hard drive to reformat it to please my employer, and while I was in there I didn't notice TOO much dust, but there was dust for sure. I will definitely clean it tonight, but I just wanted to know if there were any other steps I should take while the case is open. I did have a Mac Mini OSX CD laying around that I tried to boot it from, but it gave me kernal panic errors (maybe because the disks are intended for Intel Macs). At any rate, I found the G5 reinstall disks so maybe I should try to run the hardware diagnostic?

noiseordinance said:

Oh no, I haven't cleaned it yet.

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OK...then let's keep our fingers crossed that a good cleaning will help!

- Nick

If I may ask, what is the least amount of wires I need to reconnect? I'm not sure what all of them do, though I know where they go. Ideally, I'd like to dust out the computer, apply arctic silver to the CPU cooler (if that's possible; it looks like a piece of thermal foam is currently located there), and power it up in a minimal configuration to see if the sucker whines like crazy still... can I just hook up the case fans, or do you recommend reconnecting every wire?

So I inspected the motherboard. It was pretty dust free. However, upon inspecting the capacitors, three are heavily bulging, and two of the bulging capacitors are leaking fluid, though none appears to be on the motherboard. My question now: should I replace only the capacitors affected? The remainder of the capacitors look fabulous. I'm not the best at soldering and would rather do three capacitors and not 15-20 if at all possible.

Thanks!

EDIT: Another question is a recommended soldering iron. I have read on forums to never use anything greater than 15w, yet some forums say specifically that the G5 motherboard needs at least 60w to melt the lead free solder. So confused.

noiseordinance said:

So I inspected the motherboard. It was pretty dust free. However, upon inspecting the capacitors, three are heavily bulging, and two of the bulging capacitors are leaking fluid, though none appears to be on the motherboard. My question now: should I replace only the capacitors affected?

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So to hear that iMac is suffering from the bulging capacitor problem. This was a problem with a few different models Apple sold. Can I ask what the processor speed is on this iMac G5?

As far as replacement...I would replace all of the capacitors. The non-bulging one's may be fine...or they could go any day. If any of that capacitor fluid gets on the motherboard...it could spell real trouble!

Here are some links to help with the repair in case you don't already have them:

Imac G5 DIY capacitors repair

Capacitor kit for Apple IMac G5

YouTube - iMac G5 Capacitor Repair

Apple iMac G5 Motherboards DIY Repairs Bad Caps Fix How to Guide | According to Jim

There are plenty more links as well if you need more.

Good luck,

- Nick

Thank you much for the reply. It's the 1.8GHz G5. At this point I'm just trying to figure out which soldering iron to go with. I bought a 12w, and before I opened it, I bought a 15w since I read that a 12w might not work. Then, I read that Macs need a 60w which most places claim can melt the board. Anyone have any pointers on a specific wattage? I haven't opened either soldering iron yet.

Just a heads up. The 1.8Ghz G5 is the model before the iSight one. I have never seen the iSight iMac G5 (1.9Ghz BTW) have a bulging Capacitor. The one before it though did.

Here is that machine.

iMac G5 (Ambient Light Sensor)

noiseordinance said:

Thank you much for the reply. It's the 1.8GHz G5. At this point I'm just trying to figure out which soldering iron to go with. I bought a 12w, and before I opened it, I bought a 15w since I read that a 12w might not work. Then, I read that Macs need a 60w which most places claim can melt the board. Anyone have any pointers on a specific wattage? I haven't opened either soldering iron yet.

Click to expand...

Here's another repair procedure link...it mentions using a 60watt soldering iron (minimum):

Apple iMac G5 Motherboards DIY Repairs Bad Caps Fix How to Guide | According to Jim

Also...another link to purchase the capacitor replacement kit:

Apple iMac G5 Capacitors Kit Apple Motherboards Repair Parts Capacitors iMac G5 PSU MOB

HTH,

- Nick

dtravis7: You are right, mine is the 1.9GHz iSight version. My bad. I noticed most of the DIY guides are for the non-iSight models, but my iSight does indeed have the capacitor issue. My model appears to be the A1144, the one with the hard drive located top-center.

pigoo3: Thank you much. Maybe I'll get one of those 30w / 60w switchable soldering irons or something. I've soldered some stuff, but nothing as intricate as a mobo. This might be a good question for a soldering forum or something, but if I manage to desolder the capacitors at 60w, should I resolder at a lower temperature to stress the board out as little as possible?

Thanks guys. Very helpful.

noiseordinance said:

Maybe I'll get one of those 30w / 60w switchable soldering irons or something. I've soldered some stuff, but nothing as intricate as a mobo. This might be a good question for a soldering forum or something, but if I manage to desolder the capacitors at 60w, should I resolder at a lower temperature to stress the board out as little as possible?

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I totally understand your concerns about soldering, heat stress, and heat buildup.

I also understand your concerns about using too powerful of a soldering iron. You of course don't want to use a too powerful soldering iron..but then you don't want to use too weak of a soldering iron either. If the soldering iron is "too weak"...then it may take a lot of time to melt the solder...thus you will have to hold the tip in one place for a long time...and that can cause heat buildup as well.

That 30w/60w switchable soldering iron sounds like a good idea...if 30w isn't good enough...you can try the 60w setting.

One way to approach this (and minimize heat issues) is don't try & do the entire project in one session. Replace a couple capacitors...then take a break, let things cool off...then return to do a couple more when cool.

Good luck,

- Nick

dtravis7 said:

Just a heads up. The 1.8Ghz G5 is the model before the iSight one. I have never seen the iSight iMac G5 (1.9Ghz BTW) have a bulging Capacitor. The one before it though did.

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I just wanted to add that I have repaired two 20" iMac G5 w/iSight machines one 17" w/iSight. All three iSight machines had bulging/burst capacitors. They don't seem to be as common as non-iSight models but they definitely do exist.

daojman7 said:

I just wanted to add that I have repaired two 20" iMac G5 w/iSight machines one 17" w/iSight. All three iSight machines had bulging/burst capacitors. They don't seem to be as common as non-iSight models but they definitely do exist.

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Can you describe your experiences with the capacitor replacement?

- how long did it take?
- what sort of soldering iron did you use (number of watts)?
- did you do them all in once...or did some, let things cool off, then did the rest?
- did you replace all of the capacitors, or just the ones that were swollen/bulging?
- how would you rate the difficulty of the project (scale of 1-10, 10 being hardest)?
- any specific warnings or watch-outs for folks thinking about doing it themselves?

Thanks,

- Nick

Thanks daojman7 for the heads up. I had never seen any of the iSight models with Cap issues. Next time I am inside my 20" iMac G5 to put in a larger hard drive, I will check the caps to be sure. I was in there 1 year ago (after 4 years 24 hours a day operation) to install a new Optical drive and everything looked great at that time.

Nick, I just replaced some Caps on two switching power supplies. They were buldging and leaking. I found a dead motherboard with the caps I needed and unsoldered them. I used my OLD weller WP25 iron with a very fine tip on it. I really should have used my Weller Tempeture Controlled Solder Station to desolder the caps but the WP25 was right there so I used it and had no issues both getting out the old Caps and putting in the new ones.

I used a very powerful (Expensive also) solder sucker to clean out the holes before trying to install the new Caps.

It will be interesting to see what daojman7 has to say about his iron and how he did it.

dtravis7 said:

Next time I am inside my 20" iMac G5 to put in a larger hard drive, I will check the caps to be sure.

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With all this talk about swollen caps...I feel like I should open my iMac G5 1.8ghz (non-iSight) and check them again. I already did this when I first got it about 6 months ago, and really haven't used it much since. But who knows...plus as you know...it's VERY easy to remove the back.

dtravis7 said:

I was in there 1 year ago (after 4 years 24 hours a day operation) to install a new Optical drive and everything looked great at that time.

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I bet you really hated to turn the computer off after running it for so long. Who knows...it could still be running non-stop today...then you could say 5 years in a row!

dtravis7 said:

Nick, I just replaced some Caps on two switching power supplies. They were buldging and leaking. I found a dead motherboard with the caps I needed and unsoldered them.

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Was this on a Mac...or a Windows computer?

dtravis7 said:

I really should have used my Weller Tempeture Controlled Solder Station to desolder the caps but the WP25 was right there so I used it and had no issues both getting out the old Caps and putting in the new ones.

Click to expand...

Is that station the one with the rheostat on it?

dtravis7 said:

I used a very powerful (Expensive also) solder sucker to clean out the holes before trying to install the new Caps.

Click to expand...

I haven't used a solder sucker before. I would imagine that you have to "suck" pretty quickly after desoldering before the solder sets back up! But then at the same time not too fast..or the solder sucker tip would get burned/melted by the soldering iron.

What sort of difficulty rating do you give to a capacitor replacement (1-10, 10 being the hardest)? Remembering that you've probably done this a number of times...kind of rating the job from the perspective of the person who has never done it before?

- Nick

pigoo3 said:

I bet you really hated to turn the computer off after running it for so long. Who knows...it could still be running non-stop today...then you could say 5 years in a row!

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Agreed! I would have not messed with it but the optical drive was so bad it was at the point it would not even read a CD leave alone burn anything!

pigoo3 said:

Was this on a Mac...or a Windows computer?

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The board I removed the caps from for usage in the supply was an Intel board from a Gateway PC. The caps looked brand new but the board was dead, so I saved myself some $$$!

pigoo3 said:

Is that station the one with the rheostat on it?

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It's the older one just before that. Just a red illuminated power switch. Still gets the job done though.

pigoo3 said:

I haven't used a solder sucker before. I would imagine that you have to "suck" pretty quickly after desoldering before the solder sets back up! But then at the same time not too fast..or the solder sucker tip would get burned/melted by the soldering iron.

Click to expand...

The tip on the sucker can take quite a lot of heat. There are replacement tips when they eventually get messed up. I just heat the hole with the sucker right there and press the button and bam, hole cleaned out ready for new leads from new Caps.

pigoo3 said:

What sort of difficulty rating do you give to a capacitor replacement (1-10, 10 being the hardest)? Remembering that you've probably done this a number of times...kind of rating the job from the perspective of the person who has never done it before?

Click to expand...

If you are used to it, it's not hard. Biggest thing on multi layer motherboards is not getting it so hot and causing damage while removing the part. Putting in the new part if you take the old one out cleanly is very easy. Like me building Electronic kits when I was a young kid!

I would say taking out the old part gets a 7-9. Putting in the new part 1-2. Another thing is some boards have the leads and solder joints so close together. That makes it harder when your eyes are not what they are used to be!

dtravis7 said:

I would say taking out the old part gets a 7-9. Putting in the new part 1-2. Another thing is some boards have the leads and solder joints so close together. That makes it harder when your eyes are not what they are used to be!

Click to expand...

Quite is difference in difficulty rating between removing & installing the caps! I guess it just takes more heat to remove (plus the solder sucking)...and a greater chance of damage to adjacent components.

Of course I'm assuming the difficulty rating is looking at things from a person's perspective that had never done this sort of stuff before. With your experience...I'm guessing that 7-9 is more like a 3-4!

I hear ya on the eyes!!!

- Nick