BIC Venturi Formula 7 crossover repair

[Tennangler]

I bought these speakers new in the mid 70s. I have replace the 12" driver and the 8" midrange. I also replaced some of the LEDs in the SPL circuit.
One of SpL circuits is working as it should but the other has almost all the leds on even at low volume. Also the clipping led and the speaker overload lamps are not lighting. The input power to the crossover is 9v 300ma.
First question, how can I test the leds without blowing them.
Second question, Does anyone know how this circuit works?
These are secondary questions to my main concern which is to replace caps in the crossover. Im trying to understand which caps are for the crossover and which are for the spl circuit.
Any guidance would be helpfull.
Thank You,
James

 

[Tennangler]

I cleaned the controls and now just 2 of the leds come on. They are on even when the amp is turned off. Increasing the volume on the amp dose not change things.

 

[RVT1K]

I cleaned the controls and now just 2 of the leds come on. They are on even when the amp is turned off. Increasing the volume on the amp dose not change things.

This is a new one for me..what is the "SPL" circuit supposed to do?
Any chance of posting a schematic?

 

[Tennangler]

The SPL (sound pressure level) circuit is a row of leds that show how loud the speaker is playing.
I have read there is no schematic because BIC was constantly changing the crossover.

 

[RVT1K]

It may not be the most elegant solution but I would go ahead and replace every IC and semiconductor on that board.

 

[Tennangler]

I probably wont change out everything without understsnding how it works. At this point I will just replace the smaller caps that I assume are for the tweeter. Hopefully that will improve the sound. I can live without the SPL indicators.
Thanks for the input.
James