Emac (1.25ghz) self-repair.
Well since i'm having to do this with my own i thought i would share the process with everyone incase they have one.
- Mac randomly freezes, with or without minor graphical corruption, after a while of usage.
- Mac can boot in safe boot mode (hold shift when booting) and run without problem
What systems are effected?
- From the eMac range it seems only the 1.25ghz versions produced in 2004 are effected
Can i check without opening the mac?
- Yes, remove the ram bay hatch from the underside of the eMac and below the ram to the right will be two caps, if they have raised tops or showing signs of leakage, you're effected
How do i fix it?
- You will need to replace some, or all of the 1800uF 6.3v capacitors on the logic board
What does it cost
- Providing you have solder/soldering iron, around £15/$30
Is it permanent?
Apple did, have a logic board replacement scheme open from 2006 to 2007, however if your mac, like mine, didn't have the serial numbers they listed, or your mac simply didn't start acting up until now, the only way to fix it is to,
a) buy a new logic board
b) repair the fault yourself.
I shall now go over option B.
Once you have logic board removed from the eMac, you will need to identify the bad capacitors.. some may still be functioning, others may not, the ones that are not are easilly identifiable by a golden brown resdue buildup on the top, or a raised surface..
While you CAN only replace a few and make it work, it's best to replace all 13 of them, to be absolutely sure.
The original ones should be Nichicon branded, 1800uF 6.3v 105.c capacitors, black with golden brown stripes and text.
This is how the caps will look if theyre faulty.
Now given that the originals are 1800uF, 6.3v 105.c caps, they're actually very hard to get hold of from places other than asia, and the quality of these caps is rather questionable.
i would suggest using Panasonic branded 1800uF 25v caps, they will do the job just fine, as the voltage only effects the maximum load the capacitor can take, the capacitence is still the same.
If you're located in the UK like myself, forget maplin all together, they do not stock 1800uf capacitors.
Instead you can order them from rs-online, http://uk.rs-online.com/web/search/s...duct&R=3150625
Thankfully rs-online offer next working day delivery if the items are ordered before 8pm.
Take note, although it's possible to use 1500uF 25v caps with a 20% tollerance (can handle 1800uF), it isn't advised as the cap will be working at it's maximum tollerance constantly.
The cap locations are as follows :
the caps themselves -
the points at which they're soldered to the board (rear side)
<more will be here when my caps arrive in an hour>
If when you put it all back together you receive system beeps, consult this chart :
1 beep = No RAM installed/detected
2 beeps = Incompatible RAM type installed (for example, EDO)
3 beeps = No RAM banks passed memory testing
4 beeps = Bad checksum for the remainder of the boot ROM
5 beeps = Bad checksum for the ROM boot block
Usually reseating the ram will solve the issue.
To be continued (caps arrive in an hour)..
If you have any questions about this, feel free to ask.
DO NOT DO THIS IS YOUR MAC IS STILL WITHIN WARRANTY - DOING SO WILL VOID IT