eMac capacitors

fehervaria

Tinkerer
Sep 23, 2021
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I think I need to do a recapping sessions on my eMacs (recently picked up in Berlin) and probalby ALL of the boys and girls from the G4 era. (approximately 7 computers with their Logic Boards and PSUs... 🤪)
But at first, the very beautiful eMac 1.25 with original boxes and packaging... I changed the PRAM battery and look what I found:
IMG_5585.jpeg

The only luck with them is they are at the bottom side of the PCB and thanks for the gravity, hopfully they won't destroy the Logic Board's traces.
 
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wottle

Active Tinkerer
Oct 30, 2021
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I think I need to do a recapping sessions on my eMacs (recently picked up in Berlin) and probalby ALL of the boys and girls from the G4 era. (approximately 7 computers with their Logic Boards and PSUs... 🤪)
But at first, the very beautiful eMac 1.25 with original boxes and packaging... I changed the PRAM battery and look what I found:
View attachment 1950
The only luck with them is they are at the bottom side of the PCB and thanks for the gravity, hopfully they won't destroy the Logic Board's traces.
Let me know if you build a capacitor list when you do it. Just picked up an older eMac and will add it to my backlog of machines to recap.
 

fehervaria

Tinkerer
Sep 23, 2021
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North Germany
Let me know if you build a capacitor list when you do it. Just picked up an older eMac and will add it to my backlog of machines to recap.
Actually it is also on my todo list.
But I did the research already:
You can buy directly here - or just use the information:
or from MacRumors:

The pictures from different image searches results, showing the "capacitor" side of the 1.25GHz and 1.42GHz
eMac_LogicBoard_G4_1.25GHz.jpg
eMac_LogicBoard_G4_1.42GHz.jpg
 

alex_santos

New Tinkerer
Sep 25, 2021
40
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Oh boy. I better get my eMac out of the box and start reading the board. One more machine to recap. Well, these little beauties are hitting their 20th year.
APB: eMac Caps list wanted

This machine has a ton of caps, not just those larger caps but many small electrolytic on the main logic board and a slew of caps are to be found on the PSU and the CRT board if not some other board as well.

I found this on reddit. I can't validate any of the claims made on reddit but seeing that you have your machine partially open maybe this list of caps that I found there helps.

eMac 1GHz
-------
PSU:
Radial-

x1 100uF 35v
x1 680uF 35v
x1 1000uF 16v
x1 1200uF 35v - 3cm H x 1.2cm W
x1 1200uF 35v - 2cm H x 1.6cm W
x3 1200uF 10v
x1 1500uF 16v
x1 2200uF 16v
x2 3300uF 10v

--------

Logic board:
Radial-

x5 470uF 16v
x4 1500uF 16v
x6 2200uF 6.3v

SMD-

x6 47uF 16v
x2 100uF 10v
x2 220uF 16F ??
x2 330uF 6v



So this is the logic board and there are a lot of caps: Source of image
From the Apple service manual, there was a repair extension program for machines with a serial number range. Of course today we could consider most every eMac (any Mac really) to be at risk. Below are some of the symptoms of those faulty caps.

At the time, eMac (USB 2.0) was the affected model that Apple reported with the following symptoms.
• Scrambled or distorted video
• No video
• No power
• Intermittent system freezes or crashes
• System crashes during the startup process


I also did some research and made an image to consolidate what I could find. I couldn't find any info on the electrolytics.
Note: I did not open my machine to verify and please keep in mind that there are a few releases of the eMac and they may vary.



eMac-G4-1Ghz-.png
 

alex_santos

New Tinkerer
Sep 25, 2021
40
23
8
Actually it is also on my todo list.
But I did the research already:
You can buy directly here - or just use the information:
or from MacRumors:

The pictures from different image searches results, showing the "capacitor" side of the 1.25GHz and 1.42GHz
I came across those same links. What I couldn't do is obtain measurements for the height/width of the cap and the from the two legs. You might want to pay some attention to that as reassembly may be a problem otherwise.
 
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haydonbeagley

Tinkerer
Nov 9, 2021
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United Kingdom
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My eMac is part of the new capacitors needed club. It has some capacitors on the logic board that need some attention. At the moment it runs but it's only a matter of time before it gets too bad. My biggest issue is my soldering skills aren't the best so will likely have to buy the parts and bribe a kind friend (or someone close to me) to install the new capacitors for me. Of course paid in the right amounts of cash, tea and beers!
 

alectrona2988

New Tinkerer
Mar 10, 2022
29
14
3
k24a1.fleepy.tv
eMacs unfortunately do suffer from these quite often, and usually the through-hole ones are affected. I have never come across a unit with bad surface-mount caps. My first soldering job was a recap of a Macintosh Classic motherboard, in which I used a power dead eMac motherboard for surface mount caps. Worked well, but obviously I redid it not too long ago.

It's cool how you got a list of capacitors together. However, the ATI graphics eMacs differ in that regard. I'll have to check again, but they did use a good amount of 1500uf 16V caps.

Also the "PSU" is actually the down converter board. It takes the incoming 20V signal from the analog board (the actual PSU) and turns it into 12V, 5V, and 3.3V.

I have an eMac analog board that needs a new capacitor and I may do a writeup on how to service the analog board. Replacements are hard to come across!
 

LongAlphabet

New Tinkerer
Mar 7, 2022
18
3
3
This is great, thanks all for listing all this information. I've never 'recapped' a Mac before - don't even have the tools yet - but, given the collection I've got, I'll have to begin somewhere, sometime. I got an eMac recently - haven't opened it, but it's behavior is so erratic, there's no doubt at all that the caps are the fault. It's an ATI version (1Ghz Combo drive), so I'll recheck this thread when it comes one day, and lean on @k24a1 for any more assistance if I need it.