Fender Studio Lead Problem

[billsue]

Hello,
I am new to this site and to fixing amps, as you will soon realize. I have a Fender Studio Lead that I've had for over 20 years. It recently stopped working. The power light still comes on, but there is no sound, not even a hum. I looked at the fuses and assuming they burn out like lightbulbs do, the filament still looks intact. I don't think it has tubes....I don't see any at least. Again, I'm new at this. Does anyone have any advice on what to check for or replace?
Thanks, Bill

[metalangst]

You could start poking around with a volt meter, if you check the circuit before the power amp and you can hear a pop in the speaker, that may indicate the power amp still works. If not, then power off and drain the caps, check for shorts across transistors with an Ohm meter.

[52 Bill]

Bill, welcome to the board.

Before you start checking electronics, do as you started to do, and check the simple stuff first.

Take a spare guitar cord and plug it in the pre-amp out jack and into the power amp in jack (if the amp has them). Or if your amp has an FX loop plug the spare cord in the fx send and return jacks. If the sound returns, then you need to clean the jacks.

Disconnect the speaker from the amp and either try a different speaker or test the original one by temporarily touching a 9 volt battery across the two speaker terminals. You should hear a loud pop or crackle. If you don't, then the speaker's voice coil is open and it will need to be replaced.

If the amp has a headphone jack, plug in a set of headphones and see if there is sound there.

Let us know what you find out.

[billsue]

thanks, more info......

Hello guys, THANKS so much for your advice. I'm amazed that you both responded so quickly.

First, I plugged a cord into the pre-amp out jack and into the power amp in jack.......no sound.

Then, I did the 9 Volt battery test on the speaker.......it DID crackle.

Then, I started taking things apart. Attached to what looks like a motherboard inside are two smaller 1/2 A, 250 Volt fuses that look a little burnt in the middle. I also found the tip of an old cord plug that had long ago broken off and fell into the input jack, it was floating around loose in there. I also found what I learned was the spring reverb panel in the bottom of the amp. I took that apart and found that one of the springs that suspends it had been disconnected and it was lying on the bottom. Maybe either of these two things could have blown the internal fuses? If so, that would be a nice, easy fix.

I did pull out my voltage meter, but I'm not even sure what to test. I know there is power heading down to the reverb panel. Is the power amp the big magnetic-looking box inside? Maybe I'll replace the fuses first and go from there.

There is no headphone jack.

[52 Bill]

Use your meter to test the fuses to be sure that they are either good or bad.

The two things that you found floating around inside the amp could have blown the fuses, but they also could have done more damage first. You won't know until you try and replace them. I'd say reassemble whatever you took apart, replace the fuses and give it a try.

You may be lucky and it may work just fine.

[billsue]

Amp working!

Hello,
After replacing all of the fuses, I now have a working amp. Very excited! Thanks for your help. When the master knob is turned up past 3-4 it definitely starts to crackle though. This is a new problem, but I really can just avoid it..... unless you have advice.
Great to be on this forum, glad I found you!
-Bill