CG left channel out

[Hydrolastic]

Hello Guys. So turned on the 60 CG and the left channel has gone quiet. Couple of things to note. I unplugged the rca input plug from the right amp and there was no noise on the left side.(no hiss ,clicking, or static ) I also swapped L and R leads from my bluetooth adapter and both channels worked. Both amps are lit up on the tubes. Where to start ? Hydro

[William]

Hydro, are you saying by swapping leads on your Bluetooth adaptor the CG worked on both channels or the Bluetooth adaptor was working? Have you tried playing the radio and record player to see if either of them plays through all channels?

Bill

[electra225]

Are both amps on the left channel quiet? First suspect is always a switch. Function switch, external speaker switch. Next suspect is a Molex plug/connector. That is a chronic problem with Magnavox bi-amps as they age. My CG isn't so bad, but every time I run the Imperial, it seems like something isn't working, usually the treble amp on Channel 1.

[Hydrolastic]

Hello guys, Sorry for the late reply. I have been madly trying to get a house project done as my wife is out of town. I think you may have it nailed the molex plug, This is the strange one we talked about and I don't think it is connecting correctly. Will look at it closer.

[Hydrolastic]

Hello Guys, Update: I was heading to LA to deliver some car parts to a friend. I realized that Steve at Midcentury sound was near riverside (3 hrs away) So I contacted him about going through my CG. After owning the CG for a couple of years now it was frustrating that it was dying. first the lights went out then the magic eye stopped working and there were other issues with incorrect connectors and finally the left channel went out. I messed with the connector for hours and nothing. I have come to the conclusion this is not the console to learn on especially with so many issues. The adventure began. I disassembled the CG being methodical in labeling every fastener and found more issues. Anyways I had to get boxes and packing material. Since these were going to be shipped back to me. This took a day and a half to do.
I then went to LA and spent a few days there then on a Monday morning I took off to I-15 got a half hour into the drive to the Cahon pass and stopped and I mean dead stopped like get out of your vehicle and stretch your legs. Get in start it and move 40 ft and stop again. 5 hrs like this. The freeway was closed apparently. Something about a crime scene with a shooter and a casualty. Finally got moving again. It was a pretty good pass I had to slow down to keep the truck from overheating. IDK how hot it was but it was very hot outside. I arrived in late afternoon. Steve was understanding about the delay. We talked about what needed to be done and I brought a spare MPX unit to pirate the connectors from and the rest of the bits like the wiring with the selector switch so he could make it all work again. I suspect its going to need a lot but we will see. I may go down to get it after Christmas if its done. So that's the update ! Hydro

[William]

Thanks for sharing, Hydro, and it sounds like you had quite the adventure. I hope Steve can make it like new without breaking the bank. Good luck and please keep us posted as things progress.

Bill

[chazglenn3]

Steve will get you fixed up! Riverside? He was in Henderson, NV last I saw...maybe it's a 3 hour drive between the two...

[electra225]

As soon as I get twiddling with bakelite radio cabinets out of my system, I'd like to dig into my CG again. It will be interesting to me to see what Steve does to Hydro's CG and how it turns out. Please keep us informed, Hydro....

[Hydrolastic]

Hello Guys, I just received a video of the CG repaired. I am super happy about it. He said there were multiple repairs done that he had to reverse engineer. I will be heading down that way to pick it up soon (few weeks). Then I have to put it back together.

[William]

Good news, I sure hope it is all good and you love the sound.

Bill

[chazglenn3]

Great news! Tell Steve I said hello!

[Hydrolastic]

Hello Guys, I drove to Nevada and picked up the components of the concert Grand. Steve was really patient and we finally arrived (this trip a friend helped me with the driving ). Today I unpacked the components and started to install them. When I disassembled the stereo there was a mismash of screws. Since I had a few extra I installed the amps and the preamp out of about 30 screws and bolts I was only short 3 so tommorow I will get those at the local hardware store ( Stoneway hardware )
I noticed that the speakers were not concurrent with the rest of the console one was a year and a half newer than the other. Interestingly it looks like the left speaker was the original 943 (43rd week of 1959) The right one is the Huge Utah speaker 13 lbs. A couple of years ago I purchased a set of CG speakers and that Utah has a 944 number pretty much a match for the console and it is in really nice shape. I hope it sounds as good . We will find out tommorow !

[Hydrolastic]

Hello guys, Here we go I got the CG back together and the fasteners I needed Plugged it in and it worked for a few minutes then turned off ! After a bit. I realized it was a power issue and the PO had installed a fuse holder in the power supply A gmc 10 amp so off to the hardware store. Installed it and it blows again so I am thinking its in the power supply so I remove the power supply and with a new fuse plug it in the fuse doesn't blow. I decided to measure stuff and the outlet the cord is plugged Ito is 117v but the two outlets for the amps are 100v strange but will have to wait for another day. Then I decided to see if there was a miswired preamp plug and look at the connections. all good there then today I thought that in order for the fuse to blow there has to be a short and it has to be on one of the terminals on the preamp 12 pin molex plug. So I got my voltmeter out put it on ohms and checked each pin ton see if anything goes directly to ground. Sure enough the brown wire from the plug was shorted to ground. I followed it under the preamp and noticed there was a kind of bulkhead fitting with the wire inside was loose I wiggled the wire with the ohmmeter on it it was shorting out !
Now I have to figure out how to fix it. Here are a couple of videos
https://flic.kr/p/2qEpdDs
https://flic.kr/p/2qEod6J

[TC Chris]

Glue for a fix? I could not quite see what the part was. In the old days, car radios had pass-through devices that included capacitors to keep ignition noise out. If yours isn't that fancy, just secure it with a bit of epoxy.

Chris Campbell

[electra225]

Why would they have put a ten-amp fuse in a Concert Grand? I sure hope all the big power transformers are okay.