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PowerMac 6100 Recently Acquired, need to find out some info

So I went through my stack of Five 6100's to make 2 complete systems. I already sold one, and am keeping the other for myself. I do have some left over parts like feet if anyone is in need let me know. I recapped all the boards and power supplies so I will sell them online, if you need case parts or something let me know. Otherwise I'm getting rid of the rest. I need to clear out space and these 90's macs are just difficult to keep because of the plastics.

I like the MAC LC much better, these 6100's just have terribly bad plastic. I think I need to purge more of the macs in my collection because of this.

And for the record.. Arguing the definition of "brittle" is just a stupid waste of time...
 
I’m relatively new to this forum and I agree arguing semantics over the use of the word brittle is ridiculous.

When I got back into vintage Mac back in Jan 2020 I discovered how bad some Macs are once I started receiving shipments in the mail. My list of machines that came broken (after being perfect in an auction and generally packed well) are all of the PowerMacs, and the Quadra 605, LC/Quadra 630, and the LC 520/550/575/580. The performas from 1994- are also really bad.

Some of the best surviving machines were the LC series and most of the II series. Then came the survivability of machines due to capacitor failure. If bad plastic didn’t affect a machine, bad caps did.

I soon realized that learning how to solder and recap Macs was a priority if I was in it for the long haul. I’ve rescued almost 100 Macs thanks to learning how to recap. Sadly I lost many due to wanting them where I am and ordering them on eBay.

I haven’t yet delved into power supplies and recapping them. I plan to do that next. My first priority was motherboards.

I wish there was a better online resource for PSU recaps like there is for motherboard recaps. So far only the LC series has caused me issues with PSU failure.

Are the 6100 less prone to failure or are more powerful Macs generally using higher grade PSUs and likely don’t need a recap as quickly as the small PAU found in the LC series?

I do have one 6100 PSU that powers itself off and on rapidly once it heats up. Until it heats up it’s fine.
 
It isn't that the quality of the capacitors or the power supplies are poor. It's that the capacitors only had a rated lifespan of some 15 to 20 years. Most general purpose caps do. We are now beyond that and are seeing the results of capacitors failing due to age-related chemical breakdown and not so much electrolyte composition or amount of use. They're just old.

Plastics on the other hand, yea that's just Apple in the early to mid 90's.
 
When I said bad caps I meant presently bad caps not bad caps from back in the day.

As in, I have a bad motor on my car. Meaning it’s presently bad. I’m in a bad mood. Meaning I’m presently in a bad mood. Etc.
 
I’m relatively new to this forum and I agree arguing semantics over the use of the word brittle is ridiculous.

When I got back into vintage Mac back in Jan 2020 I discovered how bad some Macs are once I started receiving shipments in the mail. My list of machines that came broken (after being perfect in an auction and generally packed well) are all of the PowerMacs, and the Quadra 605, LC/Quadra 630, and the LC 520/550/575/580. The performas from 1994- are also really bad.

Some of the best surviving machines were the LC series and most of the II series. Then came the survivability of machines due to capacitor failure. If bad plastic didn’t affect a machine, bad caps did.

I soon realized that learning how to solder and recap Macs was a priority if I was in it for the long haul. I’ve rescued almost 100 Macs thanks to learning how to recap. Sadly I lost many due to wanting them where I am and ordering them on eBay.

I haven’t yet delved into power supplies and recapping them. I plan to do that next. My first priority was motherboards.

I wish there was a better online resource for PSU recaps like there is for motherboard recaps. So far only the LC series has caused me issues with PSU failure.

Are the 6100 less prone to failure or are more powerful Macs generally using higher grade PSUs and likely don’t need a recap as quickly as the small PAU found in the LC series?

I do have one 6100 PSU that powers itself off and on rapidly once it heats up. Until it heats up it’s fine.

6100 boards all have bad leaky caps and the power supplies are actually far worse with extreme leakage and corroding traces. I went through my stack of 6 units and only have two power supplies left to repair so I have had good luck recapping them.

The psu problem you are explaining is definitely a cap issue. Trust me even if they work, recap them as they probably have started leaking. My advice use vinegar to neutralize the corrosion, then wash extensively with water and spray on isopropyl alcohol to displace water and dry.
 
It isn't that the quality of the capacitors or the power supplies are poor. It's that the capacitors only had a rated lifespan of some 15 to 20 years. Most general purpose caps do. We are now beyond that and are seeing the results of capacitors failing due to age-related chemical breakdown and not so much electrolyte composition or amount of use. They're just old.

Plastics on the other hand, yea that's just Apple in the early to mid 90's.

I somewhat disagree with you Next. These mid 90's macs have early SMD caps that ALL seem to leak. I have devices from the very early 70's with working through hole caps that still work and have no leakage.
 
Capacitors from the 70s and prior go electrically leaky and are just as problematic. The paper insulation inside the capacitors goes acidic and starts conducting DC across them, effectively turning them into resistors. This can be more damaging than physically leaking capacitors because it'll do things like blow out transformers and red plate tubes.

Those old caps can appear fine externally but be failed internally.
 
I somewhat disagree with you Next. These mid 90's macs have early SMD caps that ALL seem to leak. I have devices from the very early 70's with working through hole caps that still work and have no leakage.

Then something is up with the formula used by United Nippon Chemi-con and Nichicon. Those two brands specifically I am seeing a lot of electrolyte leak issues.
 
United Chemi-con (subsidiary of NCC) has made shit capacitors for decades. Their KZG and KZE series have pretty much 100% failure rates.

Nichicon is a bit more dubious because there are counterfeit Nichicon capacitors that were flooded in the market for a long period of time and became increasingly hard to detect since the counterfeiters got better at it.
 
So I went through my stack of Five 6100's to make 2 complete systems. I already sold one, and am keeping the other for myself. I do have some left over parts like feet if anyone is in need let me know. I recapped all the boards and power supplies so I will sell them online, if you need case parts or something let me know. Otherwise I'm getting rid of the rest. I need to clear out space and these 90's macs are just difficult to keep because of the plastics.

I like the MAC LC much better, these 6100's just have terribly bad plastic. I think I need to purge more of the macs in my collection because of this.

And for the record.. Arguing the definition of "brittle" is just a stupid waste of time...

I Still have two feet left over, If anyone is still looking for 6100 feet send me a PM
 
You assume a fairly thick piece of plastic degrades uniformly through the material with time. The tabs that hold the 6100 cover on are fairly thick and if you don't bend them too far they usually won't snap with age.
I had 8 of them as well as many other mid 90's Mac's. They are crumbling to dust so not sure what you are talking about. Doesnt matter how thick it is. Apple must have used a terrible supplier for plastics as other computers from decades prior are still fine today. The apple II line (except for the IIc) is still in great shape and holds up to abuse today. In 20 years there wont be many left. Even the good ones will succumb then they will be chassis-less systems.

And monitors? Mac monitors seem to be even worse off. You cant pick them up in some cases.
 
Most PC makers didn't use plastic as a frame just for front panel cosmetics so they tended to not fall apart during those times.

The top cover tabs on 660av tend to break off.
 
They are all brittle. Some more than others but the whole lineup is terrible (Plastics that is). I cant think of another brand of computers that has that issue. You can bassically just say MAcintosh computers between 1988 and 1996 are decomposing to dust.
 
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