Ampeg PF 210 HE Tweeter not working

[beans-on-toast]

As was mentioned, the lamp only glows when peaks over a set level occur. It dissipates that extra power as heat and serves to protect the speakers. If the peak is too high, the bulb could blow like a fuse. If you never pushed the cab hard, it is possible that the bulb was defective from the start.

If you can't replace the part, you have to balance the cost of a new board vs paying someone to do the work.

You can try a 9 volt battery across the bulb and see if glows. You can also try shorting the bulb with a wire and carefully testing your cab to see if the tweeter comes back to life in the circuit.

 

[AstroSonic]

Light bulbs occasionally fail. Seems silly to replace the entire assembly. Just take the bulb out, test with a 9v battery as suggested by beans-on-toast. If its bad, replace it, and maybe order a spare (though the failure rate is quite low). I would also solder in a bulb socket if you are at all diy inclined.

 

[El Ted]

Ok, I get it now. Everything seems fine on the board, incl. the bulb, yet still it's not working.
I may want to test it or just get a replacement board. Thanks for your help, players! I'll post back with successful results.

 

[BassmanPaul]

Don't ever connect the woofer signal to a tweeter. it will be damaged very quickly!!!

 

[B-string]

I don't know if I missed it, has the tweeter been TESTED with a battery? I prefer 1 1/2 volt batteries like a AAA,AA or C for tweeter horns unless the 9 volt is known to be weak. Just looking at the diaphragm will not tell the condition, the voice coil can be open and "look" perfect.

 

[beans-on-toast]

Ok, I get it now. Everything seems fine on the board, incl. the bulb, yet still it's not working.

Attached is the schematic for your crossover. The tweeter circuit runs in parallel with the woofer circuit. There are a number of connections in the tweeter circuit. There could be a bad solder joint or a bad component. Look for a broken wire with the aid of an ohm meter.

 

[El Ted]

The bulb is ok, tested it with a 9V battery. The tweeter hour is working too. I guess it's got to be elsewhere on the board.
I don't think I will check all the components, it's too much. Plus, there is that cement, sticking them to the board.
I will get a new replacement board. I don't see any other component that could keep the horn from working?

Again, thank you players, for all your input!

 

[JimmyM]

Ya, if you can't fix it, and you've determined that everything else is working, your best bet is probably to replace the whole board, because getting it fixed will likely cost as much or more than replacing the board. I just hope it really is the board

 

[El Ted]

I don't see anything else, that could be wrong. I will find out soon.

 

[beans-on-toast]

The stuff anchoring the components is a glue. It allows things stand up better to the rigors of the road.

 

[El Ted]

The stuff anchoring the components is quite hard. I just don't know how it would effect the removal of the components, once they are de-soldered.
I will do one more test. Plug one of the driver's + wire into the respective contact for the horn.
If there is no signal, I think it's save to say, the culprit is one of the components on the board, or their respective wiring.

If I get the new board, which hopefully will result in my full enjoyment of this great speaker cab, I will also keep the old board.
(I hardly ever throw stuff out prematurely, that's why I have a "clutter room" in the first place).
Whenever time allows it, I may want to investigate further on it and see if I can fix it.

 

[El Ted]

Hello players,
Back with good news, I think.
Finally the replacement crossover pad arrived yesterday (yes, it took that long).
I installed it and also did a comparison between the 2 pads.
The differences between the 2 pad are very subtle, but clearly audible.
I think the cab is restored to full capability.

It was late last night, I just did the bare minimum of testing. All settings on the amp @ 12 o'clock with the cab close up to my ears.
With the old pad, I still cannot make out a difference between the off or the full position on the switch. On top of it, in any position sounds lifeless & and dull.
With the new pad, there is more brilliance in the tone, no matter what position.
On top of it, I can definitely hear the difference in either position.

I will do more playing with different EQ settings and hear what happens then.

In a response from Eminence the Tech rep recommended Delta-10b drivers for this cab. Probably more of a midrange driver then the LFs that are in the cab now.

 

[Slevage]

CAUTION this can change the impedance of your cab and can blow your amp!!

Only a tube amp.

Most SS amps can run at infinite z (open circuit, no load).