Bose 151SE Speaker Rehab

[Captbs32]

So, I have a Bose 151SE Speaker and I tested the speakers and the ohm out correctly. I tested the J1&J2 of the board and they didn't. So does anyone know where I can get a replacement board. They are pretty hard to find from just searching the internet. OR should I just make my own speaker out of something else? IF so, how would go about that. The board is attached.

 

[Alex2507]

Welcome to AH. A member by the name of TLSguy might be able to sort you out of an old parts bin. With any luck, he will be around shortly.

If it takes too long, I'll PM him.

 

[Drunkpenguin]

Is @TLS Guy the goes to bose dude?

 

[TLS Guy]

So, I have a Bose 151SE Speaker and I tested the speakers and the ohm out correctly. I tested the J1&J2 of the board and they didn't. So does anyone know where I can get a replacement board. They are pretty hard to find from just searching the internet. OR should I just make my own speaker out of something else? IF so, how would go about that. The board is attached.

Those are so called environmental speakers for outdoor use. The drivers are three 2.5" units in each speaker. They are passive speakers.

So that circuit board with hot melt crudely plastered all over the place, I think is a protection board to stop those nasty little speakers getting blown up. It looks to me as if that board is most likely a thyristor protection board. There is a component that looks to me like a thyristor, which I suspect is open circuit. I would see if you can see its details, and then get another and replace it. See if that thyristor is open circuit.

I certainly don't have parts for anything Bose and would need post aversion therapy after anything with that name on it entered my house.

 

[Alex2507]

Is @TLS Guy the goes to bose dude?

Well, maybe not.

 

[lovinthehd]

Are your speakers fully exposed to the elements? I'd simply consider another outdoor speaker and think a bit about how to protect it somewhat for the long haul.

 

[TLS Guy]

So, I have a Bose 151SE Speaker and I tested the speakers and the ohm out correctly. I tested the J1&J2 of the board and they didn't. So does anyone know where I can get a replacement board. They are pretty hard to find from just searching the internet. OR should I just make my own speaker out of something else? IF so, how would go about that. The board is attached.

So I have found the circuit in the service manual.

The twiddler speakers are 1.4 ohm and connected in series making an impedance of 4.2 ohms.

The circuit board is in series with the speakers.

Now R1, R2, C1 and C2 form a resonant acceptor tuned equalization circuit.

C3 blocks DC and prevents excessive bass getting to the tiny drivers. This will also prevent you testing for continuity with your ohm meter. It can only be checked for continuity with a signal generator.

Now as I suspected there is a protection device PTC1 which is a polyswitch, which is a self resetting fuse. They have a habit of going open circuit and not resetting. I would bet that if you replace that polyswitch your unit will work, You can test that polyswitch with your ohm meter. If it is open circuit across its terminals then that is the cause of the failure.

Now you did not state if there was any sound coming from the speaker. The PTC1 is bypassed by a jumper in series with a 100 mfd cap C3. So PTC1 being open would result from some HF coming from the speaker.

If there is no sound then C2 has failed, That is the 240 mfd cap. You can test this by temporarily jumping C2 and see if you get sound. If you do then C2 needs replacing.

You can get components from Digi-Key or Mouser electronics.