68kMLA Classic Interface

This is a version of the 68kMLA forums for viewing on your favorite old mac. Visitors on modern platforms may prefer the main site.

Click here to select a new forum.
IIci: no internal sound but sound on external speaker
Posted by: NE555 on 2019-01-18 06:24:37
All caps replaced, traces seem ok, replaced the speaker jack, but the issue is still there. Any thoughts? There is either no sound or sound with the external speaker plugged in.

Posted by: AwkwardPotato on 2019-01-18 10:23:01
Are you sure the internal speaker itself is good? Also, I wouldn't be surprised if there's some trace damage around the audio circuit given that there are some electrolytics near the sound chips and the speaker jack. After looking at the schematic, I'd recommend checking for continuity between C2 and R10, and between R10 and J23 (internal speaker connector).

Posted by: NE555 on 2019-01-18 17:07:36
Yes the speaker is good I use it for many tests.

Posted by: NE555 on 2019-01-19 07:47:31
between C2 and R10, and between R10 and J23 is continuity.

Posted by: Bolle on 2019-01-19 14:14:41
Isn’t there a switch in the headphone connector?

Not sure if all Macs had it but some did at least.

If it gets stuck it disables the internal speaker.

Posted by: PB145B on 2019-01-19 14:53:04
Isn’t there a switch in the headphone connector?

Not sure if all Macs had it but some did at least.

If it gets stuck it disables the internal speaker.
Yep! I once went through the trouble of changing the sound IC on an LC II only to find that the sound still didn't work. Plugged headphones in and sound was load and clear; unplugged them and sound was working fine again. From now on that will be the first thing I try before I go changing ICs.

Posted by: NE555 on 2019-01-19 14:53:43
Isn’t there a switch in the headphone connector?

Not sure if all Macs had it but some did at least.

If it gets stuck it disables the internal speaker.
As per my first post, I replaced the speaker jack

Posted by: AlpineRaven on 2019-01-21 03:20:16
As per my first post, I replaced the speaker jack
So if the speaker jack is not "shorted" it wont have external sound right?

Cheers

AP

Posted by: NE555 on 2019-01-21 18:05:17
I would assume so

Posted by: ktkm on 2019-11-10 05:57:37
Do you have any news regarding your speaker problem? I have the same issue with an IIci.

1