2004 eMac cleaning

[geg81]

Hello everyone,
I have just got into possession of a 2004 1GHz eMac. I have never owned a Mac before and to be honest when I saw it the first time it gave me the chills because it is built as well if not better than my 1989 IBM ps2 model 70. Stuff built not for speed but to last a lifetime.
Now the machine works perfectly but it needs a good cleaning and inspection: remove the dust, change the battery, replace the cpu thermal paste, check for dying caps and I am gonna add 2x512MB RAM sticks plus an SSD with IDE adaptor.

Given that I am accustomed with CRT work and repair, I now how to discharge the hi-voltage lines and through the years I have acquired some skills with the soldering iron, what I would like to know from you eMac owners is:

1. Is the front glass separated from the CRT? I suppose yes because the glass has acquired stains from what it seems to be condensation. I'd like to remove and clean it (EDIT: I have just seen from a service manual that the removal of the front plastic bezel is possible but it warns from further disassembly for the risk of crt disalignment... that means the front glass is a crt safety glass?)
2. are there any capacitors know to be faulty or prone to die? My line of work is "if it's working and it's working good do not touch it", but since I am already tearing the machine down replacing a couple caps won't hurt.

Thank you for your time
d.g.

 

[Intell]

The front glass is part of the CRT, it is not removable. The front plastic might be, but not recommended. The staining you see it likely caused by the anti-glare or fingerprint resistant coating starting to age.

eMacs often suffer from capacitor failures. If they haven't failed yet, they may be safe and not prone to failing. You can check for possible failures by checking for bulging or leaking capacitors.

 

[geg81]

The front glass is part of the CRT, it is not removable. The front plastic might be, but not recommended. The staining you see it likely caused by the anti-glare or fingerprint resistant coating starting to age.

If the front glass is sealed on the CRT the better because that means no condensation has (shouldn't have) gotten into between them. Or at least I hope so.
It may be an aging external coating because the staining has that striped shape like someone has tried to clean a glass with a dirty rag. Maybe the previous owner used aggressive chemicals to clean the CRT. I will check before disassembly by lightly polishing a small spot. Removing an old coating is not a problem, but shouldn't be the case, I will keep the unit as it is because it is not a big deal.

About the caps, I will check the PSU and the CRT boards.

Generally speaking the machine seems to be in good shape. I will keep it as a 9.2.2 / Tiger unit to play some retrogames on it. And it's much more stylish than a PC counterpart of its era.

 

[micahgartman]

There was a repair extension program for MLBs. Expect a dead board, dying board or a replaced board that will soon die.

eMac Repair Help: Learn How to Fix It Yourself.

The eMac was an all-in-one G4-based Mac designed for the education market and released in April 2002. It was the last Mac to use a CRT display and was sold at a low price to schools and other institutions.

www.ifixit.com

 

[TheShortTimer]

eMacs often suffer from capacitor failures. If they haven't failed yet, they may be safe and not prone to failing. You can check for possible failures by checking for bulging or leaking capacitors.

Would you recommend replacing them anyway as a precautionary measure?

What about the fly back transformer?

 

[m1maverick]

Would you recommend replacing them anyway as a precautionary measure?

What about the fly back transformer?

Age old argument. What I can say, at least with respect to SMD caps, is they can leak and, unless really bad, may not show signs of having done so. I've recapped many logic boards where the SMD caps looked OK but once removed the leakage (and corrosion) became obvious.

 

[geg81]

There was a repair extension program for MLBs. Expect a dead board, dying board or a replaced board that will soon die.

eMac Repair Help: Learn How to Fix It Yourself.

The eMac was an all-in-one G4-based Mac designed for the education market and released in April 2002. It was the last Mac to use a CRT display and was sold at a low price to schools and other institutions.

www.ifixit.com

They usually die because of failing caps. And failing caps leak. Leakage damages the board. Many 90 and early 2000 computers suffer from this. I have commodores with 40 years old caps that still work perfectly and a few amigas (the 600s mainly) I had to fully recap and rebuild corroded traces with enamelled wires.
Now, my board is not included in the extension repair program but that doesn't mean it can't fail.

Anyway, as long as I can fix it I will not trash it. Even if Apple says so.

I have inspected my board and I have an obviously failing domed cap in the rightside daughterboard. It's a 2200uF 16V cap. All the others seem ok but...

Age old argument. What I can say, at least with respect to SMD caps, is they can leak and, unless really bad, may not show signs of having done so. I've recapped many logic boards where the SMD caps looked OK but once removed the leakage (and corrosion) became obvious.

...if the SMD caps are prone to failing in the eMac (are they?) I will do another check.

I spent the weekend assembling and disassembling the machine. This unit seems to have suffered from water damage or at least stocked in damp environment because the RF shield and lower MLB frame rib are slightly corroded. Even if it is just cosmetic, more work added to the list.
Nevertheless the eMac seems to work, the PCBs are spot clean but...

1. macos 9.2.2 works without issues, still no wifi because the airport express is not supported
2. tiger installs but freezes while booting (the "wheel" stops after a few turns). I have tried to reset the PROM with no results. Maybe safebooting? It is strange because the eMac came with tiger installed and I have used it for a while before disassembling.
3. The starteck ide to sata adaptor (red pcb) does not seem to work in my eMac. Neither in cable select (like the original HD), neither in master mode. Also the pcb is too big to fit the way it was intended and I had to use a little bit of ingenuity to reassemble the MLB frame. To a more careful inspection the original HD seems to be a lower profile version (19mm?)

I do not have the original disks supplied with the machine. Is there a way to get a PPC 10.4 image that is known to work?

 

[m1maverick]

Age old argument. What I can say, at least with respect to SMD caps, is they can leak and, unless really bad, may not show signs of having done so. I've recapped many logic boards where the SMD caps looked OK but once removed the leakage (and corrosion) became obvious.

...if the SMD caps are prone to failing in the eMac (are they?) I will do another check.

I do not know if they do or not. I've recapped many compact Mac systems which are supposed to pre-date problematic capacitors and found they have had leaking capacitors. About six months ago I also recapped a Mac Portable and it had leaky capacitors. The only way to know for certain is to pull the caps and examine underneath.