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Big problem! Please help me out.

R

RedSubway

Jul 26, 2008
68
1
Indiana
#1
Alright, I have a Crate BT100 which has always worked out well for me. Yesterday, however, it stopped working.
I get no sound whatsoever; there was never any distortion, "farting" sound, etc. to preface the problem, it's as if I have the mute on. Only I don't.
I tried plugging a speaker into the External Speaker jack, and that didn't work either. So I assume it is not a speaker problem. Any ideas?
 
#2
Ok I'll give it a shot. Does the amp have a indicator light or anything that shows its getting power and attempting to turn on?

Did you check the fuse? (some amps have a second fuse hidden somewhere inside)

Did you try a diferent bass or guitar / instrement cord / confirmed good 110 volt power outlet?

If its got a headphone jack.(does it work) You might try repeatedly inserting a plug in and out of this jack. It may have a "speaker-mute" function thats simply dirty and stuck in the off position...
 
#5
I am goig a different route....

Look for any external fuse holders, check it/them or change it/them. If this does not fix your issue, schlep the amp to the local shop and let them look into it.

If you are unsure about anything inside, don't go playing grabby, grabby or poking about with metal tools.

While your new hairdoo might look funny......
 
#6
Alright, I tried the headphone jack, and that doesn't appear to work either.

The bass works with another amp, and so does the cord, so it's definitely an amp issue.

I've checked around for fuses and stuff, but to no avail, because honestly I'm not sure exactly what I'm looking for.

The amp does have an indicator light, so it clearly gets power. The electronic tuner also works, and shows the correct notes, so obviously that signal is getting somewhere.

EDIT: I'm sorry, the headphones actually DO work. So that's something.
 
#7
Ok - if the headphones work, then your entire preamp section is probably fine. Your signal is getting in to the amp fine (not the bass or cable), through the preamp section (try adjusting bass, treble, etc and you should hear that through the headphones) and out to the headphones. The next stage of the amp is the power amp.

If you have an effects loop, then it's possible there's an issue with those connections - but not very likely. (even if you're not using it, depending how the amp is wired)

Most likely... either the power amp section fried (did you smell anything?), you popped a fuse (did you find a small fuse, sometimes it looks like a black plastic knob that is the cap that holds it in?), or something came loose on the way to the speaker.

(I don't suppose you have a "mute" button by any chance, right?)

Can you post a picture of the back of the amp?
 
#8
I do have a mute button, and you don't know how much I wish I had just forgotten and left the mute on haha.

I can get a picture of the back, but there's nothing except jacks for External Speaker, the amp footswitch, effects loop send and return, and a balanced line out.
 
#11
If I recall correctly, the external speaker jacks on those units were in series with the internal speaker. Therefore, if there were an open circuit to the internal speaker, the external speaker would not function. I'd check the connections at the speaker, at the circuit board, and if those are intact, it could be the speaker itself. Having signal at the headphone is a good sign it might not be too serious of an issue.
 
#12
Alright here's the deal. I got it to work for like two seconds, and it seems pretty clear that it's a connection issue between the speaker and the amp. Unfortunately I'm not quite sure where; do you think it's a problem with the wires connecting the two, or at the connection points themselves?
 
#15
~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Hi! I'm your friendly amp technician! I live perhaps thousands of miles outside the range of hearing and seeing your amp - even when it's turned up and working! So I've devised this handy questionnaire! In order to help me more efficiently diagnose and repair the problem with your amplifier please respond to the following points:
~~~~~~~~~~~~~~~~~~~~~~~~~~~~

1. Describe your problem:

2. Now, describe your problem accurately:

3. Speculate wildly based on faulty knowledge about almost everything
just what's the cause of your problem:

4. Please indicate the severity of your problem:
A. Minor___ B. Trivial___ C. Minor___ D minor, the saddest of all keys___

5. Nature of problem:
A. Sounds bad___ B. Sounds really bad___ C. No sound___
D. Strange smell___ E. Smells really bad twice___

6. Was your amp plugged in?
Yes___ No___

7. Was it turned on?
Yes___ No___

8. Did you try to fix it yourself?
Yes___ No___

9. If so, did you make it worse?
Yes___ Yes___

10. Did you have a "friend" who "knows all about amps" try to fix it
for you?
Yes___ No___

11. If so, did they make it worse?
Yes___

12. Have you read your manual?
No___ No___

13. Do you have the manual?
Maybe___ No___

14. Are you absolutely SURE you read the manual?
I was going to___ No___

15. If you think you read the manual, do you think you UNDERSTOOD it?
Yes___ No___

16. If YES, explain why you can't fix the problem yourself:

17. What were you DOING TO your amplifier at the time the problem occurred?

18. If you answered "nothing", explain why you think there's a problem:

19. Do you have another amp you can use while you wait to take this one
to a repair shop like you should have done in the first place?
Yes___ No, I prefer to be out of commission longer___

20. Are you sure you're not imagining the problem?
Yes___ No___

21. Does the clock on your DVD player always blink 12:00?
Yes___ That's a clock?___

22. Do you have an independent witness to the problem? (Does not
include drummers)
Yes___ No___

23. Have you given the amplifier a good whack on top?
Yes___ No___

24. Did the amplifier catch fire?
Yes___ Not yet___

25. Has the foam or insulation inside your speaker enclosure
ever caught fire?
Yes___ No___ Huh?___

26. Did the insulationy stuff inside your speaker BOX catch fire?
Yes___ No___

27. If so, did you replace it with an approved dampener?
Yes___
No, enough beer gets spilled in there to keep it safe___
No, the cat whizzes in there after a good scratch on the
carpet anyway___
 
#16
The headphones work off the power amp. so your assumption of a bad connection is almost certainly right.

The headphone jack has a contact that opens the speaker ground when you plug in. Obviously that could be a problem. The ground on the jack is evidently good enough to run headphones.

Yes, the external speaker jack is in series. It could be the problem. There is a contact in it to short it through if nothing is plugged in.

The problem obviously could be in the wiring.

The wire might have fallen off a connector inside. There are wires and connectors from the board to the internal speaker, and back to the external speaker jack, then to the headphone jack. Any of those could have a problem.

The speaker itself might be bad, which you can check by unplugging it and checking by connecting a flashlight battery to the ttwo terminals of the speaker(some disassembly required). It should move a bit and make a noise if it is good.
 
#17
Nice one Greenboy haha.

Alright, thanks everyone for the help, it appears it is the headphone jack! I'm relieved it isn't anything more serious. One of the little things isn't making the connection, which is strange because I never use the headphone jack.

Anyway, any idea how to get it to stay down?
 

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