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| LC III Small Whine |
Posted by: Johnnya101 on 2017-04-08 13:11:28
Im buying an LC III off craigslist, and the seller said it has a small whine, which they think is the fan. I asked back if its coming from the monitor (Flyback) or the actual computer.
Lets say its coming from the computer. What could be the cause of this? PSU? Or the fan? etc?
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Posted by: Bolle on 2017-04-08 14:01:44
LCs usually whine from the speaker when caps go bad.
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Posted by: Johnnya101 on 2017-04-08 14:13:17
Yup, thats what Ive been just reading. Should've searched it first.. oh well.
Thank you!
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Posted by: belgaonkar on 2017-04-08 17:17:32
Interesting, I didn't know that. My LC II was making an annoying noise from the speaker. I though the speaker went bad and just disconnected it. Looks like Ive got another project on my hands.
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Posted by: Johnnya101 on 2017-04-08 17:47:06
The seller keeps saying their husband is saying its the fan... Oh well. When I get it tomorrow Ill show them the leaking caps.
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Posted by: belgaonkar on 2017-04-08 18:05:56
I would not open up a computer while with the seller. On the few occasions I have done it, they seems to get spooked. Many of the people who still have old LCs or Quadras are not that tech savvy (minus collectors) and they are easily scared by you opening the machine. They feel as though you are going to damage it in someway. The only time I would open up a machine would be if it wasn't posting/working properly or if I see corrosion/dirt on the case.
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Posted by: Johnnya101 on 2017-04-08 18:12:50
They know a little about them and have already opened the LC. Besides, the LC only has those two tabs that you push right? Ive never had one.
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Posted by: rsolberg on 2017-04-08 18:28:31
Also, if the machine should take that opportunity to pack up and stop working, or a tab should break off the case, the seller may feel that it's your responsibility, whether justified or not. If they're comfortable opening it, ask them to do so for your inspection.
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Posted by: Johnnya101 on 2017-04-08 18:46:48
Of course! Id have them open it anyways.
Ill update tomorrow which I think I am getting it then.
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Posted by: belgaonkar on 2017-04-08 18:52:07
Yes, it is the two tab one, and if they are familiar with the workings you should be fine. The fact that they think it is due to the fan means they have some technical knowledge.
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Posted by: Nathan on 2017-05-07 09:20:55
LCs usually whine from the speaker when caps go bad. That's good to know. My poor LC II was whining so much yesterday I was concerned the hard drive was finally looking to bite the dust. Of course it turned out to be the speaker. Unplugging the speaker made the noise go away but curiously seemed to interfere with booting with it unplugged. I think the sound might have gone away after I plugged the speaker back in, but probably means I should check the caps.
Is the whining only due to bad motherboard caps or is the power supply also capable of causing the same problem?
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Posted by: bibilit on 2017-05-07 09:32:51
Mainly caps issue...
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Posted by: belgaonkar on 2017-05-07 10:08:52
Yep, my LCII had the same issue. When you unplug the speaker the noise stops. I cleaned the board with water and the problem has gone away. I have ordered new caps but need to find time to install them.
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Posted by: agent_js03 on 2017-05-08 07:04:37
I bought a cheap LC III on craigslist as well. After 25 years, that plastic gets really brittle. Be careful with those tabs, mine are completely broken off
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Posted by: Juror22 on 2017-05-10 21:25:37
Be careful with the internal plastic tabs, they get brittle too.
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Posted by: agent_js03 on 2017-05-11 06:09:56
Be careful with the internal plastic tabs, they get brittle too. Yep, those have broken off for me too. I just settle for a mobo and fan that are loose inside the case.
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Posted by: Nathan on 2017-06-22 12:53:56
Ah, plastic tabs. I swear everything inside the LC II is held in with them. It sure makes taking all the stuff out easy, but it does make you a little nervous. Luckily it's fairly obvious the ways they're supposed to bend to get stuff out and they're very easy to see, so there is less chance of accidental breakage.
I took the LC II motherboard out and swapped my LC III board into the case, which is surprisingly clean, maybe all the dust is getting stuck on the fan (it's pretty dusty), today since a brief inspection confirmed fairly obvious capacitor leakage in multiple place(I'll post some pics later for reference). It looks like there's a little corrosion on some IC pins too so it's due for some kind of help.
So, for starters what's the best way to clean off the gunk/goo/residue? Also, is there a good way to get the capacitors off the board (mostly the metal can ones with plastic bases)? I figure I won't be using the board anytime soon so removing the caps and cleaning off what gunk I can is the best I can do for now. It still boots so far so hopefully nothing's damaged beyond repair.
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Posted by: Johnnya101 on 2017-06-22 13:47:42
90% alcohol, you can get away with lesser %, scrub with toothbrush, then I think scrub again in distilled water, and AIR COMPRESS dry!
I would hold off on removing the caps, as it will be harder when you want to replace them wondering where to put them! (Until you look up a schematic), but for removing them, just look it up, tons of stuff.
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Posted by: Nathan on 2017-06-22 21:11:41
Here are some pictures: http://imgur.com/a/YfR2J They're a bit too big for the post I think.
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