Fixing a Bassman 400 210 combo

[JeezyMcNuggles]

If I can't get the speakers running I can still at least use this amp and run it out to a different cab. I got it for basically free so if I have to drop a few hundo on a 4x10, oh NOOOOO now I have an amp and cab setup that's functional but a little cumbersome.



Fantastic catch, I'll pull the other driver out tomorrow and check it as well. If one of them is hooked up wrong, chances are pretty good that another wire clip somewhere in there is jacked up as well

Yeah, that's what I was thinking. Never know.. could be that simple. It could also just be the output's blown. Thats what I chalked mine up to. Couldn't figure anything else out. Hopefully not though. Hopefully it is something stupid like this.

 

[BogeyBass]

The amp works. Main fuse isn't a issue.

You can push on the Speakers see if there is rubbing or any strange feel to it. Or measure resistance on the speaker terminals.

 

[chadface]

Are these drivers wired in series or parallel? If it's series, all it will take is one driver to fail and both won't work.

The picture looks like it is wired parallel.

I would start by checking the wire nuts inside of the cab. I doubt those are oem.

I am guessing it's definitely worth the effort to fix. I had a bassman 100 of the same generation and it sounded very good. Yours is a much better model and I'm certain it will sound great.

 

[Downunderwonder]

I DID get a pop out of the speakers when I maxed out the gain. Once

If it's series it is not adding up unless you popped one into oblivion right there. I don't see enough to tell if it's series or parallel.

So someone smoked an attenuator in the past perhaps. No sign of that on the board now.

For my my money I would cut the tweeter and crossover right out of it, test the drivers independently with battery and then I would know what I got. Measure the DC resistance of each speaker to figure out an impedance wiring scheme.

 

[Downunderwonder]

Yeah it looks like it's wired in series...it goes from the control board to the left driver and then from the left driver to the right driver.

I had another look. Between what I can see and what you are saying it looks like there's one pair of black and white that goes straight from output to first speaker both terminals and then on to second speaker. That's parallel. If you pull the wires from the output of the attenuator board and briefly stick 9v across, both speakers should jump.

 

[BucketOfFish]

Check those two wire nuts. Unscrew them and verify a good connection.

 

[popgadget]

What happened with the 9v test directly to the speakers?
That actually is a very good sounding combo when it works, if the drivers are in fact bad, your money would be best spent by replacing them. I’m pretty sure that they are 2 8 ohm woofers wired in parallel for a 4 ohm load to the amp.

 

[nabilhuakbar]

I had another look. Between what I can see and what you are saying it looks like there's one pair of black and white that goes straight from output to first speaker both terminals and then on to second speaker. That's parallel. If you pull the wires from the output of the attenuator board and briefly stick 9v across, both speakers should jump.

Interesting, I always thought that was "in series" since one was wired directly after the other.
I'll give that 9v test a shot later today or tomorrow when I've got a minute.

 

[BioWeapon]

The clip is supposed to be on the peg (attached to it), not under it.View attachment 3950316 is this the only one like this? Or...

Cause the positive on the tweeter is hanging off the post. That's a bad connection. If the other speakers look the same, pull them off,, squeeze the clips together, lightly, and try to get better connections.

That looks connected to me. Some speakers have 4 connection tabs, two exactly where those wires are and two facing 90 degrees outwards from them.

A disconnected tweeter also will not cause the 10" speakers not to work!

 

[agedhorse]

There are usually 2 terminals on those tweeter, available with terminals parallel to each other or at right angles to each other. Can't tell which style from the photo.

 

[BobKos]

What's up with the wire nut connectors? Bet that's not stock which suggests somebody has been playing around with it already. Unfortunately you don't know what they were messing with so you don't know what to un-do. Also unfortunate is that you have to assume everything they did was completely wrong until proven good. If the amp were mine I would carefully track the wiring from the amp section to each speaker to make sure connections and polarity are all as they should be. You can do a quick test on the speaker drivers with an ohm meter as they will read roughly the same as their rating. You SHOULD be able to disconnect the wire nutted wires and test the whole speaker loop in a similar fashion. Make sure you mark the wires before disconnecting so you can at least get them back the way they were (right or wrong). There may be more fuses inside the amp but they may or may not look like anything you have ever seen. Truth told you shouldn't be messing with the fuses if it powers up. Fuses in and of themselves almost NEVER fix anything. A blown fuse is the final product of another underlying problem. Also - the scorching' appears to be black overspray from when the cab was built.

 

[Downunderwonder]

Interesting, I always thought that was "in series" since one was wired directly after the other.
I'll give that 9v test a shot later today or tomorrow when I've got a minute.

Series wiring connects the speakers like end to end1.5v batteries in your TV remote.

Yours looks to be wired from the amp to one speaker then both terminals are onwards wired to the same ones on the other speaker. Parallel.

If it goes amp to + through speaker one out - to speaker two + through speaker two out - back to amp, that's series.

 

[BassmanPaul]

I forgot to mention that the battery test should not be used on the tweeter only the woofers.