Crate TD-70

[nevjim_3]

I have a Crate TD-70. I was playing the other day and suddenly lost my output. If you crank it you get sound on both channels, but very low output. Any ideas, I do not have a schematic.

[Jazz P Bass]

Can you post the schematic?

[nevjim_3]

I don't have it, thats part of my problem.

[52 Bill]

Are there any break jacks on this amp, like an FX loop or power amp in?

[nevjim_3]

Only line in, line out and foot switch

[52 Bill]

Take a spare guitar cord and plug it into the line in and out jacks. Does this restore the signal?

[nevjim_3]

Sorry, got interupted. No it did not change

[mozwell]

This may help.
Try checking the mute transistors Q5 & Q18, maybe disconnect the drain lead, and see if the problem, goes away.
First, check power supplies, TP11, TP12 should have +/-38V, TP13 shoudl have 300V, check +/-15V on pin 4 & 8 of the 8 pin ic's.
Check the 5W & 10W resistors, are all of these ok, measure (with pwoer off) with an ohm meter, do they read correctly.
Pull the valve (with power off), reinstall it & jiggle it in the socket

Inject a signal & check the signal from the input to the output, to find out where the signal drops out....

[nevjim_3]

First off, thank you for the schematic. I will check these tonight when I get back from practice. Thanks for the help.

[52 Bill]

And make sure that the extension speaker jack's normally closed contact is closing as well.

[Capture Ratio]

Hey, nevjim_3, my TD-70 does the same thing. Starts out fine and then cuts out after a few chords. Sometimes it sputters back in. You can still hear a little output but not much. I replaced the tube but no change. Tonight, on a different forum I found the following:

For any TD70 amp owners who have had their amp cut out once in a while: I had the same issue and found that the fuse clips on the PCB board were faulty. They would easily fracture and cause intermittent operation of either the main inputs or the line in. I think the mertials were defective when manufactured based on the number of complaints I heard about these amps cutting out. The good news is that it is a simple fix (once you know what the problem is!). Just have the fuse clips replaced and you are back to rocking in no time!

I'm hoping that fuse clips are easy to replace and are available at Radio Shack (anybody know?). Hope this helps!

[nevjim_3]

Thanks for all the info guys. I got pulled away for other priorities for a few days. I am printing the schematic right now and i will let you know what I find.

[moodysj]

I have a TD35 and had the same problem. The input jack had a cold solder joint. Re-soldering the jack fixed it for me.

[nevjim_3]

So how does Crate expect you to find anything when there are no parts designators on the board?

[Jazz P Bass]

So how does Crate expect you to find anything when there are no parts designators on the board?

Ya gotta use Voodoo, man