1968 Silver Face Fender Bandmaster fix

[The4455]

My school had a Bandmaster sitting around and I asked if I could try and fix it. Now it's in my basement and I need some help. The cord had beet cut/torn and needs a new plug. the original one was in the amp head, but it's a two prong one. Should I reattach that one or use a three prong one and how would I go about that? I also need to put in a new 2 amp slo-blo fuse, but the plastic cap that keeps it on is missing. Is there an easy alternative to one or can I order just that part from someplace, also does it matter which end goes into the amp and which end isn't?

I found this article and my amp is similar in terms of the power cord situation. Should I do as this guy says?
I can post pictures if that would help.

http://www.premierguitar.com/Magazine/Issue/2010/Dec/Sprucing_up_a_60s_Blonde_Fender_Band_Master.aspx

[eatyourguitar]

replacing the cable is a good start but remember some vintage two prong fender amps can kill you even when they are new. it is what we would call a very unsafe design. I saw a vintage princeton reverb that was modded for 3 prong plug by a professional. the guy selling it said that the amp was also modded to reduce hum but I don't know if that is a direct result of the 3 prong plug job or not.

[The4455]

So, yes. I should replace the power cable's end with a three prong end.

[morange]

Yeah. I don't think it's too hard. Look up instructions about how to do it online somewhere (it's a common modification, for safety), because you need to do it right. Like, you have to remove the "death cap", and wire the ground prong to the chassis securely.

You know about draining the filter capacitors, first, right?


For example, here's just one example of a tutorial:
http://www.unclespot.com/2to3prongconversion.html

Also, I've bought amp stuff from http://tubedepot.com/ before. Lots of places online have tube amp building stuff, like fuse holders, three prong cords, wire, solder, etc.

[The4455]

Thanks. In the tutorial I'm assuming that I attach a brand new cable or do I just adding a three prong connector to the end of the existing cable?

The amp hasn't been turned on in at least eight years, should I still drain the filter caps?

[morange]

Yeah, follow the steps to just in case. Takes like 15 seconds. It's your life we're talking about, so don't take chances.

[youtube]http://www.youtube.com/watch?v=a21e54eJy2I[/youtube]

The three prong connector needs three wires in the cable. Get something like this: http://tubedepot.com/p-12pwf.html

[The4455]

i just got the parts I needed from the Tube Depot, thanks Morange.
I found this video:

[youtube]http://www.youtube.com/watch?v=LW4FLjQfIqw[/youtube]

Should I just follow this guy's instructions? I thought I'd run it by you guys first before I start, I don't want to hurt the amp or my self on this one considering how badly either could go.

[morange]

Anyone who has ever said "That's what Fender does, so who are we to say we should do any different" is a twat.

That video seems right at first glance. Compare your work with a diagram when you're done, to make sure.

He didn't mention it, but remember to drain the filter capacitors before you do anything else.

In the video comments someone mentions that he didn't use a lock washer on the ground lug. You should use one to make sure the ground wire stays tight on the lug it's mounted to.

When you're done and have the amp closed up, an easy way to see if you've wired the fuse correctly by taking the fuse out of the holder and turning on the amp - it shouldn't turn on.

[The4455]

Anyone who has ever said "That's what Fender does, so who are we to say we should do any different" is a twat.

That video seems right at first glance. Compare your work with a diagram when you're done, to make sure.

He didn't mention it, but remember to drain the filter capacitors before you do anything else.

In the video comments someone mentions that he didn't use a lock washer on the ground lug. You should use one to make sure the ground wire stays tight on the lug it's mounted to.

When you're done and have the amp closed up, an easy way to see if you've wired the fuse correctly by taking the fuse out of the holder and turning on the amp - it shouldn't turn on.

Thanks, hopefully tomorrow I will.

[The4455]

I changed out the power cable and installed a new fuse holder. I turned the amp on and nothing happened. I plugged a one spot into the outlet on the back and it worked. I let the amp sit over night with it plugged in and this morning it didn't work either. I'll open it back up to check my wiring again, but I don't think that's the problem.

[morange]

Damn. The only other easy thing I can think of is trying a different set of tubes. This thing may need the attention of a good amp tech.

[The4455]

I'll take soem pictures of the tubes so you guys can take a look at them, I'm assuming their the originals, that being said they're 45 years old.

[The4455]

Here are pictures of the left 6l6:

[The4455]

The right 6l6:

[morange]

Is the fuse good?

The power tubes being bad wouldn't effect the pre-amp tubes or the power indicator lamp; something would still start glowing when you turn on the power. You said nothing at all works, right? I think it's some kind of power problem, since nothing happens.

If you check the fuse and check your wiring, and it still doesn't work, I don't know that there's much else you can do without more know-how and equipment. The power transformer might not be working, but I'm no tech; it could be a lot of things. I think you need a tech to figure out what is wrong with it, at this point. Someone can get in there and tell you exactly what's wrong. You don't want to start buying replacement parts without knowing for sure what the problem is.

Maybe you could look up an amp tech near you, with a good reputation, and ask them if they could have a look and give you a quote for what the repairs would cost (and tell you what is wrong, too). I'm sure you'd have to pay for this diagnosis, but not a lot, I don't think; I don't think it would take very long.

Since you've turned the amp on, remember not to put your hands inside the amp without draining the filter capacitors again.

Those are some pretty sweet old tubes. I don't know if you can tell whether they work just by looking at them. You could try them in an amp you know works, to see, I guess.