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No Sound on a IIci
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Dennis Nedry
Well-known member
Last I checked you can't really test capacitors with a multimeter. You need some pretty fancy equipment to directly test a capacitor, either that or to build a circuit and observe if it performs properly. You will definitely need to remove a capacitor from the circuit board to test it because the other components it's connected to will change the reading.
I'd go ahead and replace them anyway. I think the caps in IIci's are old enough that they should all ideally be replaced by now. If they aren't leaking yet, they probably will soon.
I'd go ahead and replace them anyway. I think the caps in IIci's are old enough that they should all ideally be replaced by now. If they aren't leaking yet, they probably will soon.
Dennis Nedry
Well-known member
Added note: You can do a VERY rudimentary test of a cap with a multimeter in continuity mode. Hooking the cap up to the multimeter should show up as an open circuit (infinite ohms, or needle at original position on the left side). It is possible with large capacitors for it to take several seconds for the reading to settle back down to infinite ohms.
This test is only conclusive if the cap reads less than infinite ohms for a very long time, this indicates a short circuit in the cap. But no other situation can be detected this way. (i.e. leaked and dried out caps still test as open circuits)
It is very possible for a capacitor to have degraded and now has a different actual capacitance than it used to have, but still functions like a capacitor, just the wrong size now. It either requires a calculated circuit and oscilloscope or some dedicated equipment to test the actual capacitance (in Farads, usually µF, nF, pF range). Even with this, bad capacitors may test good because they may function fine at low voltages used for testing but fail at the higher voltages present in the actual circuit board they came from.
In short, capacitors are CHEAP, and it's usually a much better use of time to just replace them instead of bothering with testing.
This test is only conclusive if the cap reads less than infinite ohms for a very long time, this indicates a short circuit in the cap. But no other situation can be detected this way. (i.e. leaked and dried out caps still test as open circuits)
It is very possible for a capacitor to have degraded and now has a different actual capacitance than it used to have, but still functions like a capacitor, just the wrong size now. It either requires a calculated circuit and oscilloscope or some dedicated equipment to test the actual capacitance (in Farads, usually µF, nF, pF range). Even with this, bad capacitors may test good because they may function fine at low voltages used for testing but fail at the higher voltages present in the actual circuit board they came from.
In short, capacitors are CHEAP, and it's usually a much better use of time to just replace them instead of bothering with testing.
beachycove
Well-known member
Run the board through a dishwasher cycle, dry for some days, reassemble, and fire it up.
Worked a treat on my SE30 and Classic II.
Worked a treat on my SE30 and Classic II.
Dennis Nedry
Well-known member
They're actually just as easy to replace. You can see a little tiny bit of the leads where they're connected to the logic board on each side. Just heat each one with a soldering iron, lift it up a tiny bit, heat the other one, lift it a tiny bit, and go back and forth as many times as you feel comfortable until it pops right off! Putting the new ones on is much easier.
As long as you take your time and don't pull too hard, you'll be OK. If you pull too hard, the trace on the logic board (the green lines) may peel off. So just take your time and it'll be fine.
Like I always say, find some old broken electronic junk that contains these kind of caps and practice with it first.
As long as you take your time and don't pull too hard, you'll be OK. If you pull too hard, the trace on the logic board (the green lines) may peel off. So just take your time and it'll be fine.
Like I always say, find some old broken electronic junk that contains these kind of caps and practice with it first.
LCGuy
LC Doctor/Hot Rodder
You'd need to use a temperature controlled soldering iron though wouldn't you? I'd be afraid to even think about trying it with my soldering iron - its just a cheapie from Dick Smiths thats either on or off, no adjustment. That thing gets so hot I'd be afraid of melting something!
Dennis Nedry
Well-known member
I use a low-power soldering iron that I got at Radio Shack. You really should use a low-power one, it's probably also good to get one with a grounded plug. I don't think it gets too terribly much hotter than what is required to melt solder.
Dennis Nedry
Well-known member
Then that could be a different story.
I believe there's a little switch hidden inside the sound output port that turns the internal speaker on and off. You can try plugging something in and unplugging it a few times to see if that helps the connection, and also you can check to make sure the speaker works.
I believe there's a little switch hidden inside the sound output port that turns the internal speaker on and off. You can try plugging something in and unplugging it a few times to see if that helps the connection, and also you can check to make sure the speaker works.
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