2300c runs hot

[beachycove]

How hot does a functional Duo 2300c run? Does anyone else have one who could tell me?

I have a unit that freezes persistently. I cannot, for instance, run it long enough to get a 7.6.1 install done in a Dock. I had thought that the trouble was a dodgy drive, but I replaced the offending item yesterday with a known good drive, only to find that there is no improvement in the behaviour of the machine. I now wonder if the problem might be due to a heat buildup in the CPU area. The area gets noticeably hot after the 2300c has been running for 20 mins or so.

The 2300c has a large copper heatsink that covers much of the area beneath the keyboard, so presumably heat was an issue with the 603 chip. Although I have read that the 603 ran cool (compared to the 601), and so mediated the transition to the ppc powerbook, it couldn't have run all that cool. This one certainly doesn't.

It's not a big deal, as the machine isn't mission-critical or anything, but I'd like to get the old girl into working order. I love the Duos and also have a Powerbook 280c and a 270c. (The 270c runs especially cool, by the way, which I rather like, as it means that I am not wasting battery power on warming my knees. It is by far and away the more energy-efficient of the three).

Would a fresh daub of paste/ grease on the 603 chip help resurrect my 2300c, do you suppose?

 

[bigD]

Would a fresh daub of paste/ grease on the 603 chip help resurrect my 2300c, do you suppose?

I think that would certainly help - all these machines are getting to the age where the grease is breaking down and the heat sink isn't cooling as well as it should. I'm not sure how hot a 2300c should get, but some new grease definitely won't hurt.

 

[Temetka]

While you're at it, go ahead and give the whole system a nice cleaning. Removing dust from vent ports and cleaning fans (if any) can reduce temps by a noticeable margin.

 

[Mike Richardson]

5200s and 5260s also use PowerPC 603 processors, which tend to overheat and freeze up these days due to dried up grease, so I always clean off the grease and put some new stuff on. It helps a lot with the random bombs, etc.

 

[30pin]

I usually use a product called Arctic Silver 3. It is really supposed to conduct heat well. I usually use it when I am cleaning up any older computer that uses a heat sink.

 

[beachycove]

Well, I've had it apart and discovered that there is no thermal grease on the 603 chip. No sign of any at all. Clean as a whistle. I can't see how there could have been any applied at manufacture. What there is is a mechanical arrangement that applies pressure to keep the heatsink in contact with the processor.

More importantly, I discovered that the area that is getting especially hot is to the left of the CPU, and a little further from the whole CPU area (as in, 2" or so) than I had thought. The area in question has a concentration of several largish capacitors. So maybe it's the infernal capacitor problem once more.

There is no obvious sign of leakage, but as I have replacement caps with the required ratings, I think I will replace the capacitors, clean the logic board up, and see what happens. I can't make it much worse, can I?

Overheating is indeed symptomatic of capacitor failure, is it not?

 

[beachycove]

The freedom of a Friday afternoon at home has allowed me to fiddle with the 2300c some more. I ran it for 20 mins to get it good and hot in order to see where the trouble lay. I now suspect that the offending item was a small square copper-wound component (transformer?) at the left under the keyboard, which was very hot to the touch.

As this component cannot be replaced, I have adjusted the heat sink to make better contact with this component. Since booted again, the 2300c has run without crashing for some hours. The machine is still hot at the left, like many ppc powerbooks, but so far, and with this small adjustment, it runs without complaint.

I also recelled an old Duo battery with fresh NiMh cells. What a business! There isn't much room in there, is there? In fact, I was unable to get the top back on properly, so I have glued the little buggers in place, cut part of the top off and glued it on (so as to be able to replace the sliding cover), and all seems to be good. Electrical tape went on there too.

This is the first time I have been able to use the 2300c for any real length of time. I have previously used a Duo 270c and 280c, but find the small screen a challenge. The 2300c screen is not as sharp as the gem-like 270-280 series, but it's bigger and that helps. It's a rather elegant little unit, and evidently very lightly used in the past. I've installed 7.6.1 with Speed Doubler and Wordperfect 3.5e, a 48MB chip for 56 MB total, and a Toshiba 3GB HD. I have three good(ish) Duo keyboards (and two absolute duds), so I have also installed the best of the three keyboards on this one (and have no complaints to make about it). If I can get it to run reliably, and assuming that my battery continues to work as expected, I think I'll try a major writing project on the thing, as it is so much more compact than my Wallstreet, which I have lugged about for years, and so much more expendable in terms of the threat of theft in libraries etc. than a Macbook or the like would be. Retro goodness.

 

[MultiFinder]

I've never really noticed that my 2300c runs hot, let alone even warm. And yeah, I've noticed that if I take mine apart right after running it for a while, those little transformers are practically the only things that get warm in there.

 

[beachycove]

I've never really noticed that my 2300c runs hot, let alone even warm. And yeah, I've noticed that if I take mine apart right after running it for a while, those little transformers are practically the only things that get warm in there.

That's the sort of info I was asking for. Adjusting the heatsink helped tremendously, but maybe I still have a problem, as the whole "top left" really is noticeably warm. I have also found since my previous posting that the 2300c is not charging batteries properly. Capacitors?

 

[MultiFinder]

I've never really noticed that my 2300c runs hot, let alone even warm. And yeah, I've noticed that if I take mine apart right after running it for a while, those little transformers are practically the only things that get warm in there.

That's the sort of info I was asking for. Adjusting the heatsink helped tremendously, but maybe I still have a problem, as the whole "top left" really is noticeably warm. I have also found since my previous posting that the 2300c is not charging batteries properly. Capacitors?

How did you "adjust" the heatsink? Perhaps since things are rather tight in there you're accidentally crossing something preventing the battery from charging properly? Check a bazillion times to see if anything's touching anything in there. Also, I've noticed on both the Duo boards I have that those little transformers seem to whine a bit. Do yours whine?

 

[beachycove]

I simply bent the heatsink to make contact with the copper-wound transformer (which is insulated). The heatsink is shaped so as to do so, but maybe it is not meant to touch the thing. I think I will ferret out a service manual just to check on your suggestion, since it makes perfect sense.

In response to your whining issues (ha), I had an unstable Duo 280c (capacitor leakage) that had the whine from that area, but I have functional 270c and 280c Duos that are perfectly silent. The 2300c is also silent, but it has some other issues, as we see.

I had a peek at a PB145 logic board the other day. It has no capacitors at all. My Wallstreets also have no cap-capacitors to speak of, excepting the battery charge card. The Duos have lots. This has to be a major failure point in this model; could the whining be related to capacitor failure?

 

[MultiFinder]

I simply bent the heatsink to make contact with the copper-wound transformer (which is insulated). The heatsink is shaped so as to do so, but maybe it is not meant to touch the thing. I think I will ferret out a service manual just to check on your suggestion, since it makes perfect sense.
In response to your whining issues (ha), I had an unstable Duo 280c (capacitor leakage) that had the whine from that area, but I have functional 270c and 280c Duos that are perfectly silent. The 2300c is also silent, but it has some other issues, as we see.

I had a peek at a PB145 logic board the other day. It has no capacitors at all. My Wallstreets also have no cap-capacitors to speak of, excepting the battery charge card. The Duos have lots. This has to be a major failure point in this model; could the whining be related to capacitor failure?

Also, while you're in there, check the condition of the little rubbery-thingy between the CPU and the heatsink. I can imagine that it would break down over time, so might wanna give that the once-over.

That's rather disconcerting about the caps... Mine looked fine when I was in there. Maybe I'll give 'em a better look next time I have this little bugger apart... It's not so much a whine as it is a light hum of sorts. I hope that caps aren't an issue in these laptops. Has anyone else ever had capacitor issues with their Duo that they can share with us?

Also, should you need the service manual, I have a PDF of it. PM me and I can e-mail it to ya.

 

[tomlee59]

If you are worried that the capacitors themselves are emitting audible noise, I think you can relax. It is much more likely that the inductors/transformers are making sounds. If the windings are a bit loose, or the core isn't well locked down, they'll vibrate and make noise.

Defective capacitors can indirectly cause noise in audio circuits through a variety of mechanisms, but for the capacitors themselves to emit noise is unusual.