Conion c100ff issues

[SDConion]

First post. Need some guidance over here.
I've had my box for over 10 years now and finally took it out of the attic to clean it up a bit.
It is far from mint (but has the tape door haha) and not really worthy of a restoration but I would like to get a few bugs figured out.
When full of batteries, everything works minus the tuner LEDs. I plan on putting this unit in the house and would like to plug it into AC power. So I purchased a new power cord and plugged it in. With just the AC cord plugged in, I only get the tuner LEDs. When I have the AC cord AND batteries in, it all works.
Where should I start?

I did a search and could only find the "block diagram" that shows where each plug goes. Has anyone scanned the actual wiring schematic?

 

[caution]

The tuner bulb uses straight AC off the transformer, so it will never light up on batteries.
When you put a cord into the socket on the back, it pushes on a switch to disable the batteries.

 

[SDConion]

Ok. That explains part of it then. Shouldn't there be a rectifier that converts AC to DC? Could someone point out where that is so I can test it? Is there anything wrong with having the AC cord AND a 15v DC cord plugged in at the same time? I tried this and it works...kinda.
When it runs on batteries, the power and sensor buttons functions as they should. However when I use the AC and DC combination, the power button doesn't function and everything stays on. Weird right?
Thanks for the response!

 

[caution]

Shouldn't there be a rectifier that converts AC to DC?

The bulb uses AC. That's what everyday light bulbs use.

Could someone point out where that is so I can test it?

The transformer in the radio has a second output winding that gives out about 7V AC for the bulb, it's the green and yellow wires running from the transformer board to the power switch board.

Is there anything wrong with having the AC cord AND a 15v DC cord plugged in at the same time?

No, because as long as you have an AC cord plugged in, it keeps a switch pressed down that disables the DC side, which includes both the batteries and the 15V DC cord.

However when I use the AC and DC combination, the power button doesn't function and everything stays on. Weird right?

First of all, you're not using anything "in combination" because as long as you've got the AC cord plugged in, DC is disabled. Please keep in mind that this radio has the ability to also turn on and off without the use of the power button, you do it by playing or recording in the lower tape deck. Although, it is advised to use the power button at all times since it uses a better grounding and reduces overall hum.

 

[SDConion]

Ok things are working as they should now, I think.
Tape1 was stuck in play...easy fix since the case is split in half currently. So now the power button works correctly.
The AC plug switch that disables the DC voltage source works. With only the AC power cord plugged in, only the tuner LEDs work. Shouldn't the AC cord turn on the entire unit?

 

[caution]

I'm not sure I know what you mean by tuner LEDs. A bulb illuminates the tuner window. Are you talking about the LED audio level meters under the tuner window?

 

[SDConion]

Sorry about that. I'm referencing the lights that illuminate the radio frequencies. The rows of red LEDs work as the should.

 

[caution]

One of the diodes in the rectifier that generates 15VDC might have failed. It seems like the transformer is OK, since the other winding is still powering the tuner bulb.