I've checked for continuity through the plug/switch/fuse and all is good there. I went to test the first two test points, but I am not getting any ac readings through them. As I am a noob, I want to be sure I'm testing right.....do I put the black end of the multitester to the chassis ground and the red on the metal part? Or do you test on either side? I attached a pic to show what I'm looking at, it's in the middle of the picture.

I will be testing more today, I bought a continuity tester but it was faulty so I have to exchange it. Once I have that I can test for continuity in the plug, switch and fuse. I will have to take the PCB off the chassis to see the solder points underneath as well. My multitester doesn't have continuity testing, but could I test for continuity using the ohms setting (for future reference)?

Thank you yet again for the advice! I built the light bulb limiter last night, so the fun will begin tonight. All of the tips above should keep me busy for a while 

Thanks for the info Phil, but I want to make sure I am testing right. Do I pull the transformer terminals and test for voltage or do they need to be plugged into the PCB board to be tested? I did pull the terminals and tested and there is no voltage across the terminals. The fuse had blown as well, so I think I need a light bulb limiter in order to do further testing.

Looks like I purchased the correct fuse, as it matched what was on the chassis. Put it in but now no power, I will look at the other posts to see how to trouble shoot this.

Thanks to the both of you for the explanations, it really helps moving forward!

I bought a fuse exactly like the one that was in the amp, but I will check the chassis. I also picked up the supplies for the light bulb limiter, as I figured I would need it.

The Yamaha amp has an input jack and a headphone jack, so I was utilizing those to test the effects loop. Hopefully that wasn't a mistake.

I will try all the suggestions and post what I find. Can't thank you both enough for all the help.

I have attached pictures of the board, the front of the amp and the closest schematic I could find (Studio 85). The amp was apparently functional before shipping but not now.

Hi there, first time poster. I've been reading the different topics here to try and trouble shoot my problem, but I'm stumped.

I bought a Fender 85 off Ebay, and when it arrived I couldn't get any sound through the speaker, just a low hum. Here's what I've tried:

1. Tested the speaker with a multitester and it is functional.
2. Tried each input (this one has 2) with different cords and different guitars that work on my other amp.
3. Tried running a cord between the effects loop inputs, no sound.
4. Tried using with headphones, no sound.
5. Tried running my iPhone through the inputs, very faint sound through both and the volume would go up and down.
6. Tried running my other amp (Yamaha THR10X) through the effects loop and got sound through the Fender speaker! But then the fuse blew.


I have a schematic for a Fender Deluxe 85, but very low knowledge of electronics and only a multimeter to test.

Are there any ideas as to what the issue is?