[GTALUG] Acer Aspire 3 A315-21 laptop has mono sound only?

[Ken Heard]

Hello,

On 19/03/20 05:44 PM, Ken Heard wrote -- my original post on the subject:

> 
> Hello,
> 
> On 19/03/20 05:44 PM, Ken Heard wrote -- my original post on the subject:
> 
>> I think that this particular laptop has mono sound.  I have been using it temporarily to stream content by HDMI to a LG HD monitor and then by fibre optical cable to a NED D3020 V2 hybrid amplifier and finally to a pair of bass reflect speakers.  Unfortunately sound comes out of only one speaker.
>>
>> After extensive tests I have determined to my satisfaction that the problem is in the laptop.  I can test the two speakers built in the laptop separately, but I have no way of knowing whether the sound so produced is mono or stereo.  I could find no specs for this laptop with details about the sound card.


First, my apologies to all for my tardiness in not answering sooner the 
responses I received about the problem explained in my original post. 
All were helpful.  My tardiness was caused by problems with my desktop 
which had to take priority, such as a failed hard drive and for a few 
days every boot's starting by opening the BIOS with the message "BIOS 
has been reset – please decide how to continue". After dealing with 
these and some other problems I resumed efforts on my part to solve the 
problem described in my original post quoted above.

In the second quoted paragraph I claimed that I had made extensive 
tests.  Unfortunately they were not extensive enough. This time I did 
the sensible thing, I started by testing the Acer laptop alone. I 
connected a pair of ear buds to the laptop 3.5 mm earphone jack and 
streamed something from YouTube which had sound.  What I heard in *both* 
ears was sound!  So much for my nonsense of only mono sound; the laptop 
was doing perfectly what it should.

I then repeated with more care the tests previously done as to why there 
is no sound to the left speaker when connected by an HDMI cable from the 
laptop to the monitor.  To start these tests I used camcorder to provide 
sound input.  The HDMI connecting cable in this case has a mini HDMI 
plug at the camcorder end and a standard size plug at the other. By 
disconnecting the amp from the monitor, plugging the buds directly into 
the monitor headphone jack and plugging the HDMI cable successively into 
the two HDMI input jacks in the monitor I heard sound in both ears in 
both cases.

I then connected the monitor to the amplifier and repeated the same 
tests described in the previous paragraph. There was sound from both 
speakers in both cases.

The next series of tests involves connecting the two HDMI cables I have 
between the laptop and the monitor.  Both have standard size plugs at 
each end. On is a cheap 3 metre one; the other is 5 metres long and of a 
higher quality.  For these tests each cable was plugged successively to 
both jacks in the monitor, and both cables were tried in each direction 
between the laptop and the monitor.

I first disconnected the amplifier from the monitor and listened on the 
buds plugged into the monitor 3.5 mm headphones jack.  I repeated these 
tests with the amplifier connected by a fibre optic cable to the monitor.

The result for all the tests described in the last two paragraphs was 
the same.  In every case there was sound from only one channel. (I also 
made sure that each speaker could work if plugged into the right speaker 
jacks.  They both did.)

To me it seems improbable that both HDMI cables would be faulty at the 
same time; that surely is too much of a coincidence, especially as one 
is supposed to be a good one. If that assumption is correct then the 
HDMI jack on the laptop must be at fault.  At the moment however I only 
have one source to test both cables, only the laptop.

I do have however a desktop computer which I purchased in 2015 and 
installed Debian Wheezy in it.  This computer is the one I have normally 
used ever since, the laptop since 2018 being the backup.

In the past four years however -- in spite of much on line research and 
numerous posts back and fourth on the Debian user list -- I was never 
able to get sound to work, .  It is now my intention – once I have a two 
month window in which to do so – to replace in the desktop Wheezy with 
Buster.  With any luck I may have only sound working on it.

On that assumption I will have another device to test both HDMI standard 
cables. If only one of them works in these tests then the question to 
answer is why it did not work for the laptop.  If both work on this 
device then the fault must be the HDMI jack in the Acer laptop.

Regards, Ken