Must freeze my Mac G4 (literally) to start it.

[John Shreffler]

I have a strange problem with my G4 desktop. If it shuts down, I must put it in a freezer for a few hours in order to start it. Mac 1 GHz Power PC G4 OS 10.3.9 and Classic 9.2, Flat screen on top of a hemisphical base. At the moment, I am using a UPS to help prevent power down, but in case of extended outage, that does not work. I wonder if anyone could shed some light on this. Macintosh repair shops won't touch it. I suspect it is some failed component in the power management circuit, that is temperature sensitive. But I am far from being an expert.

 

[Cory Cooper]

Hello and welcome.

I strongly suggest you do not continue putting the Mac in the freezer and then powering it on. When it is removed from the cold temperature, if it is not left to come up to room temperature for the proper amount of time, you could end up causing more damage to the internals, or cause an actual fire. If there is any residual condensation on the logic boards and/or in the power supply itself, powering it on could cause a spark or short, and the LCD panel is not built to withstand this type of treatment, which could lead to discoloration in the panel itself.

My guess is that the internals of the base aren't being cooled properly by the fan during operation because the vents are clogged with dust (a known issue with that model), or simply some of the power supply components are failing due to age. It could also be the PRAM battery, if you are experiencing any issues with the clock resetting and not displaying the current time after a power down. Since it won't power back on after shut down, it could also be that the thermal paste has dried and isn't making contact, which would prevent a kind of thermal lock until it cooled down enough to make contact. Because of the unique construction of that model, it is NOT a user-serviceable Mac, and only qualified technicians should attempt to troubleshoot/repair it. There are a couple of disassembly/assembly steps that should be performed in the proper sequence, and require non-standard tools for proper torque.

Bottom line, it isn't safe to continue your "fix" procedure. In addition, because it is going on 13-14 years old and running Mac OS X Panther 10.3.9/OS 9.2, I am sure you are having more difficulty using it successfully on modern websites and cannot update any of the software you may use on a daily basis. Unless you can find an Apple Authorized Service Provider that is willing to take a look at it, I would just retire it and replace it with a newer model. Even if they could determine any faulty parts, they are officially discontinued and can be very hard to find and expensive.

C

 

[John Shreffler]

Hello and welcome.

I strongly suggest you do not continue putting the Mac in the freezer and then powering it on. When it is removed from the cold temperature, if it is not left to come up to room temperature for the proper amount of time, you could end up causing more damage to the internals, or cause an actual fire. If there is any residual condensation on the logic boards and/or in the power supply itself, powering it on could cause a spark or short, and the LCD panel is not built to withstand this type of treatment, which could lead to discoloration in the panel itself.

My guess is that the internals of the base aren't being cooled properly by the fan during operation because the vents are clogged with dust (a known issue with that model), or simply some of the power supply components are failing due to age. It could also be the PRAM battery, if you are experiencing any issues with the clock resetting and not displaying the current time after a power down. Since it won't power back on after shut down, it could also be that the thermal paste has dried and isn't making contact, which would prevent a kind of thermal lock until it cooled down enough to make contact. Because of the unique construction of that model, it is NOT a user-serviceable Mac, and only qualified technicians should attempt to troubleshoot/repair it. There are a couple of disassembly/assembly steps that should be performed in the proper sequence, and require non-standard tools for proper torque.

Bottom line, it isn't safe to continue your "fix" procedure. In addition, because it is going on 13-14 years old and running Mac OS X Panther 10.3.9/OS 9.2, I am sure you are having more difficulty using it successfully on modern websites and cannot update any of the software you may use on a daily basis. Unless you can find an Apple Authorized Service Provider that is willing to take a look at it, I would just retire it and replace it with a newer model. Even if they could determine any faulty parts, they are officially discontinued and can be very hard to find and expensive.

C

 

[John Shreffler]

Thanks much for your reply. I did disassemble a bit, enough to vacuum all dust out of the computer. and to replace the battery. Actually, I don't have to put it in the freezer to get it to start. It is just faster to go to the freezer. A good long soak in the refrigerator at 40 degrees will also work. I also can get it to start by setting the base down on a group of freezer packs or even a handful of dry ice. In this case, the LCD panel does not get cold. Before doing this I put the computer in a plastic bag in a room with low humidity, to keep condensation at a minimum.

Once it is running, it is fine, although as you guessed, it is worthless for browsing the web. Gets hung up trying to cope with scripts and Java and all the modern stuff. I use it ony to edit my web sites, using very old versions of DreamWeaver and PhotoShop, which I am very fluent with, and would like to keep using.

If anyone has a schematic of the part of the G4 that does the power management, it would be a big help. I am thinking that I could get down to the Mother Board and hit components one by one with a freeze liquid and try to find the bad one for replacement.

Thanks again for the reply.

 

[Cory Cooper]

No worries.

I still don't recommend any of the cold methods.

Apple actually doesn't release schematics for any of their products, not even to the Apple Geniuses or Apple Authorized Service Providers. They only service their products with part swaps and not component level repairs. Only Apple Engineering, the super-secret group that designs their products, has access to that type of information.

Sorry, but unfortunately there isn't any additional support that we have access to.

C

 

[John Shreffler]

I understand. But I thought there might be a one in a million chance that someone had this problem and could shed some light.

 

[Cory Cooper]

I appreciate your understanding. I wish there was more we could do to help you out, it's just beyond our collective experience.

Sorry again, and I hope you find a solution. If I come across anything I will be sure to let you know.

C