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emacs and capacitors

Bobdude161

Bobdude161

macrumors 65816
Original poster
I posted a thread a while back about eMacs with bad capacitors. I had 10 eMacs with this problem and 3 of which were still under warranty. The other seven are rotting away now. I've now decided that since I'm out of warranty, I'll have to fix them myself. I know when Apple repairs these eMacs they get fresh new logic boards. I think that is an expensive option.

I'm wondering if the capacitor problem lies within just the capacitor and nothing else on the logic board. If that's the case, I can de-solder the old capacitors and solder on new ones. I just need to know if that is a fact, that replacing the capacitors will fix the problem and that the capacitor problem is not a symptom of something else going wrong on the logic board. Anybody know? Thanks. 🙂
 
should be the typical problem...

i know on several of our dells and quite a few imac g5's that the capacitors that blew were made by nichicon (black case with a silver stripe), usually with an X pressed into the top of the case (K imprints are usually ok). the HM's from nichicon have been known to blowout, but can easily be replaced. i've done it several times and they seem to be permanent fixes. well, unless you count the one where the guy spilled coffee on the imac and it blew all of them. you can get them from mouser if you know what cap you need (typically the HM(M) 6.3v ones) and you can search for UHM0JxxxMPD where xxx is the speed, such as 222 for the 2200uF, 152 for the 1500uF.
 
De-soldering could depend on if they are Surface mounted or not.
Surface mounted components are tiny things, maybe 1mmx3mm. It is possible to hand solder them, but bloody difficult.
 
emac capacitor replacement

Hello, This is just a heads up to people who are interested in replacing emac capacitors. Here is my story. I have an emac that was listed with bad capacitors. Unfortunately I didn't get it in the shop within the 3 year window. I took it upon myself to disassemble the computer using tips on the web. I removed the CD rom, hard drive and logicboard. I contacted my local TV repair shop who were happy to take the business. They replaced a total of 8 bad capacitors. I only provided them with the logicboard all else was removed. The total cost was 90 dollars and a bit of my time. The computer is put back together and running fine so far. Had I took it to an authorized dealer it would have meant an hour and a half drive 1 way plus more money in repairs I am sure. So with all that said if you feel comfortable taking the computer apart (a challenge for me) this is not a bad way to go in my opinion. Best of luck, bill
 
killybay said:
Hello, This is just a heads up to people who are interested in replacing emac capacitors. Here is my story. I have an emac that was listed with bad capacitors. Unfortunately I didn't get it in the shop within the 3 year window. . . . Best of luck, bill
Click to expand...

Well, I've got a similar scenario. I've unsoldered the two capacitors that my local Mac shop said were the most likely culprits, but they test out OK (although the freezing problem is intermittent, so they may well fail when they get warm). My problem is finding a suitable source for replacements. Maplin can supply the 1000uF component, but the only supplier I've found for the 1800uF is an eBay in China, in a pack of 30. I'm exploring searches for 'motherboard capacitor' - and finding out it's quite a plague!

If anyone knows of a (preferably UK) supplier that will sell me small quantities, I'd be grateful.

Cheers, Mark
 
I am a very basic solderer and was wondering if any of you could please point me in the right direction for replacing these capacitors.I have not started disassembly yet but open opening the bottom door there was an exploded K capacitor off the bat. My problem with the eMac 1.25 is a small thin line in the middle of the CRT. Video out seems to be fine. Maybe this is just a burnt CRT or I probably just have to take it all apart and check out the capacitors. I guess I am a bit lost any help would be greatly appreciated thanks.
 
@emacspy - If you've got a line, your crt isn't dead, so that's the good news. And the problem's not on the MoBo - good news too I guess.

So something's stopping the electron beam waving up and down to make a picture - that could be as simple as a bad connection in that whole mess of stuff that hangs off the back of the crt, or more likely a component that's fritzed in the high-voltage area. More than that I daren't venture, for fear of getting rotten tomatoes thrown at me . . .
 
@NostradamusZen:
Any local supplyer of electronic parts should be able to sell you such parts (even in quantities of 1), IF they are not surface mounted (so the capacitor has pins which go through the PCB). Buying them in a store will safe you from paying more for the shipping than for the parts. Be sure to tell the store the rating (Voltage and Capacity) and the pin grid (mostly 2.54mm or 5.08mm (0.1 oder 0.2 inch)).
 
emacspy said:
My problem with the eMac 1.25 is a small thin line in the middle of the CRT. Video out seems to be fine. Maybe this is just a burnt CRT or I probably just have to take it all apart and check out the capacitors. I guess I am a bit lost any help would be greatly appreciated thanks.
Click to expand...

If your eMac uses a Trinitron screen you may just be seeing the wire that holds the aperture grille in place over the electron gun. 15" screens have a single wire about two-thirds of the way down. Larger screens have two.

This is a design feature, not a flaw 🙂
 
Wow thanks for all the informative replies! The small line is about a quarter to half inch of very blurred video in the very center of the screen. It seems to boot up as gray and then turn blue when osx starts up. I have noticed a blown K capacitor right behind the ram door not sure if this means anything. I will be fully taking the eMac apart tomorrow so I can post an update and pictures. Also the crt seems to have a high pitched sound if left on for a little while. Your right Im hoping its just a loose connection or something if not I may just do the 17" LCD mod when I get a little extra cash for one. I may try to fix the capacitors myself but my de soldering technique needs work still. Im using thin copper de soldering braid and practicing on old crashed motherboards. Thanks again for all the great help and I really like this forum everyone has been wonderful.
 
Place to buy caps

The best place I have found to buy caps is thecapkingDOTcom. Free shipping in the US and $5 international plus no min order. You can check out capacitorlabDOTcom for more info as well. I have seen a few G5s with this issue and was able to get them back up.
 
tb421ny said:
The best place I have found to buy caps is thecapkingDOTcom. Free shipping in the US and $5 international plus no min order. You can check out capacitorlabDOTcom for more info as well. I have seen a few G5s with this issue and was able to get them back up.
Click to expand...

Thanks for that! I've just ordered from CapKing, and hopefully my friend's eMac will be back on track. Cheers, Mark
 
Replacing Bad Caps in eMac

I know this is an old thread but I am in the process of replacing bad caps on my eMac 1.25 processor and I found a supplier for the caps but didn't realize until after removing them all that there are two different types. Now I don't know which type goes where. They are identical except the rating and voltage. I was wondering if anyone has seen or has a schematic of the mother board or a map showing what goes where.

Thanks!

Stacey
 
Acesymmetric said:
I know this is an old thread but I am in the process of replacing bad caps on my eMac 1.25 processor and I found a supplier for the caps but didn't realize until after removing them all that there are two different types. Now I don't know which type goes where. They are identical except the rating and voltage. I was wondering if anyone has seen or has a schematic of the mother board or a map showing what goes where.

Thanks!

Stacey
Click to expand...

I just happened to pull this mobo from a 1.25 Ghz model just yesterday.

The one's labeled 1800 are 6.3 volts
The one's labeled 1000 are 16 volts.
 

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Has anyone seen any different configurations for these Emacs? I would like to put a kit together that would cover them all. So far everything I have seen has said:

8X 1800uF 6.3v 10X16mm
5X 1000uF 16v 10X16mm


Thanks,
Troy
 
I've replaced capacitors on three 1.25ghz boards (all the same). I think you only need to replace the 8 1800uF 6.3v capacitors - not the 1000uf ones. The 1800uF capacitors will have bulging or leaking tops. Two of them can be seen by removing the memory slot cover on the bottom of the emac- one on either side of the memory slots. It takes a large amount of disassembly to get down to a bare motherboard and then you need good soldering skills/equipment to replace the capacitors - a lot of work for an old computer.
Finding I didn't have the skills/equipment necessary to remove the old capacitors, I just used a wire cutter to clip off the old capacitors and solder the legs of the new ones to those of the old ones. If you use the wire cutter to sort of crimp/cut the old capacitor around the circular depression at the bottom of the capacitor, you can get it off while leaving a 1/4" of the legs attached to the motherboard. If you don't leave any of the leg intact, it makes it more difficult. After soldering on the new capacitors, I bent the legs so the capacitors lie sideways, not straight up- otherwise, the capacitors won't fit.
I've been using one emac on a regular basis for about five months and it's fine so far. The other two work but don't get regular use.
Also, you can often get emacs with bad capacitors to work (for awhile) by removing the ATI8500... kexts from the Extensions folder. (Boot in safe mode, go to hard drive:system:library:extensions and delete(first back up to another folder) the five files starting with atiradeon8500..) You lose certain capabilites such as playing games or using dvd player (applications that rely on video card capabilities) but you can use most applications just fine.
 
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gripnrip said:
I've replaced capacitors on three 1.25ghz boards (all the same). I think you only need to replace the 8 1800uF 6.3v capacitors - not the 1000uf ones. The 1800uF capacitors will have bulging or leaking tops. Two of them can be seen by removing the memory slot cover on the bottom of the emac- one on either side of the memory slots. It takes a large amount of disassembly to get down to a bare motherboard and then you need good soldering skills/equipment to replace the capacitors - a lot of work for an old computer.
Finding I didn't have the skills/equipment necessary to remove the old capacitors, I just used a wire cutter to clip off the old capacitors and solder the legs of the new ones to those of the old ones. If you use the wire cutter to sort of crimp/cut the old capacitor around the circular depression at the bottom of the capacitor, you can get it off while leaving a 1/4" of the legs attached to the motherboard. If you don't leave any of the leg intact, it makes it more difficult. After soldering on the new capacitors, I bent the legs so the capacitors lie sideways, not straight up- otherwise, the capacitors won't fit.
I've been using one emac on a regular basis for about five months and it's fine so far. The other two work but don't get regular use.
Also, you can often get emacs with bad capacitors to work (for awhile) by removing the ATI8500... kexts from the Extensions folder. (Boot in safe mode, go to hard drive:system:library:extensions and delete(first back up to another folder) the five files starting with atiradeon8500..) You lose certain capabilites such as playing games or using dvd player (applications that rely on video card capabilities) but you can use most applications just fine.
Click to expand...

Whoa! Thanks for that info! I never thought of just cutting the legs. Thank you!
 
Small Quantity of Caps in UK.

Hi Mark
I can supply you with the small quantity of caps you are after to repair your eMac.
I am in the UK and sell components on ebay, my screen name is CarmelsSemiConductors if you are interested in other components for Mac's.
Regards
Carmel

NostradamusZen said:
Well, I've got a similar scenario. I've unsoldered the two capacitors that my local Mac shop said were the most likely culprits, but they test out OK (although the freezing problem is intermittent, so they may well fail when they get warm). My problem is finding a suitable source for replacements. Maplin can supply the 1000uF component, but the only supplier I've found for the 1800uF is an eBay in China, in a pack of 30. I'm exploring searches for 'motherboard capacitor' - and finding out it's quite a plague!

If anyone knows of a (preferably UK) supplier that will sell me small quantities, I'd be grateful.

Cheers, Mark
Click to expand...
 
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