National Panasonic SG-1200L - UK Vintage Radio Repair and Restoration Discussion Forum

Philmac · 17th Oct 2020, 5:51 pm

Hi, I have just got a National Panasonic SG-1200L. It's in a really good condition, however only one speaker is working. I have checked both speakers and they are OK, I do think it must be the stereo itself. Anyone any ideas?

SiriusHardware · 17th Oct 2020, 6:17 pm

Hello Philmac - welcome to the forum. If this unit has a headphone socket, try plugging phones in and see if you get sound out of both sides of the headphones or only one.

If you have one side on phones missing as well, try the unit in every mode (ie, with every sound source) to see if the channel is dead on all sources or only one.

Philmac · 17th Oct 2020, 8:40 pm

Hi, thanks for your reply. When the headphones are plugged I get sound out of both sides

OldTechFan96 · 17th Oct 2020, 9:07 pm

My neighbour has a similar Panasonic unit which had an identical issue with the cassette deck. Cleaning the record/play switch inside of the unit with switch cleaner brought back audio to both channels.

SiriusHardware · 17th Oct 2020, 9:09 pm

Quote:

When the headphones are plugged I get sound out of both sides

That's usually good news, although we will need a look at the circuit diagram to be sure. Just check whether, when you unplug the headphones, the original problem (one speaker off) is still there or whether it has now 'cured' itself.

Can we ask how you determined that both speakers were OK? (You haven't said what you have in the way of measuring / testing equipment.)

Philmac · 18th Oct 2020, 10:26 am

Hi, just checked and when the headphones are unplugged the problem is still there. The way I know that both speakers are working is because I unplugged them at the back and switched them over and plugged them back in. I don't have any measuring or testing equipment

17th Oct 2020, 5:51 pm	#1
Philmac Diode Join Date: Oct 2020 Location: Lincoln, Lincolnshire, UK. Posts: 3	National Panasonic SG-1200L Hi, I have just got a National Panasonic SG-1200L. It's in a really good condition, however only one speaker is working. I have checked both speakers and they are OK, I do think it must be the stereo itself. Anyone any ideas?

17th Oct 2020, 6:17 pm	#2
SiriusHardware Dekatron Join Date: Aug 2011 Location: Newcastle, Tyne and Wear, UK. Posts: 11,560	Re: National Panasonic SG-1200L Hello Philmac - welcome to the forum. If this unit has a headphone socket, try plugging phones in and see if you get sound out of both sides of the headphones or only one. If you have one side on phones missing as well, try the unit in every mode (ie, with every sound source) to see if the channel is dead on all sources or only one.

17th Oct 2020, 8:40 pm	#3
Philmac Diode Join Date: Oct 2020 Location: Lincoln, Lincolnshire, UK. Posts: 3	Re: National Panasonic SG-1200L Hi, thanks for your reply. When the headphones are plugged I get sound out of both sides

17th Oct 2020, 9:07 pm	#4
OldTechFan96 Octode Join Date: Jul 2017 Location: Newcastle Upon Tyne, Tyne & Wear, UK. Posts: 1,181	Re: National Panasonic SG-1200L My neighbour has a similar Panasonic unit which had an identical issue with the cassette deck. Cleaning the record/play switch inside of the unit with switch cleaner brought back audio to both channels.

18th Oct 2020, 10:26 am	#6
Philmac Diode Join Date: Oct 2020 Location: Lincoln, Lincolnshire, UK. Posts: 3	Re: National Panasonic SG-1200L Hi, just checked and when the headphones are unplugged the problem is still there. The way I know that both speakers are working is because I unplugged them at the back and switched them over and plugged them back in. I don't have any measuring or testing equipment