CB President Lincoln- no transmitting

Your link as provided - didn't open - at least not for me.

There are a few reasons it may not be transmitting. "Not transmitting" could mean it isn't "transmitting" over a distance - or "not at all". There "is" a difference.

1. Do you have a "Mic" wired "properly" to it - to activate the PTT relay and provide modulation?
2. Do you have a good antenna and cable attached to it?

If the signal is not going out over the air - assuming a good mic and antenna system, then it is possible/likely - your problem is internal to the set. The "RF Amp Transistors" could be shot, the PLL system shut down or shifted far enough to cause no operation.

From your question - "because of no additional pin connection backside of radio" - not being able to see your intended picture(s) - I must wonder if you are even using an antenna. You "should" be.

That radio has a coaxial antenna connector on the backside. It needs an antenna or a dummy load.

The website quoted (in a strange language) states that on the rear auxiliary connector pin 1 and 7 need to be connected.

Shows some schematics - pins 1 / 7 seem to have something to do with enabling the internal speaker.

Pres Lincoln...CB Radio... brings back the 70's for me :-)

Wasn't that the same as an HR2510?