Dead Fisher 400

I put it on a shelf in my basement about three months ago and it was working fine. I hooked it up last night and it’s dead as a door nail.

I pulled the fuse, it looked good and now I’m out of ideas. Anyone know of something I could try before I take it to a tech? It’s been restored but it was about 10 to 15 years ago.

 

Replace the fuse anyway and check the plug.

 

Probably a good idea, I’ve never replaced it and I’d certainly love to keep the cost to that of a new fuse. The plug looks fine and the connection at the chassis looks solid as ever. It is odd that its completely unresponsive to electricity. As if it’s not getting any.

 

. . . which is exactly what happens when the fuse blows. It can happen to vintage (and some not-so-vintage) components stored in less than perfectly dry storage.

 

Indeed, there is no visible burn or break but I will make that my next step.

 

Looks clean

 

Do the switched outlets on the back turn off and on with the power switch? (Plug in a lamp or something).

 

New fuse, no difference

 

No power coming through those outlets.

 

I suspect the power switch. The outlets would still switch on even if the fuse was blown if the power cord coming in and the power switch were both good.

 

I was thinking that as well. The power knob has been busted in the on position for years and I’ve been using a switch on the power cord. A fairly common and difficult repair on the 400. I don’t know how sitting a shelf would switch it to off but that’s clearly a suspicious spot and a reasonable explanation.

 

You can troubleshoot it from there with a no contact neon bulb AC tester which is a good thing to have. If it's difficult to replace I'd look into shorting it out.

 

I hate Fisher products with a passion. Both my dad and I have had the same thing happen with a couple of their turntables 5+ years ago. Both were put on the shelf, time passed, plugged the one in and it wouldn't power on. Tinker with it a bit and got it to turn. The other one the platter wouldn't spin, tried replacing caps, ic's, etc..... Never could figure out what happened to that one. Put it back on shelf with a note for part out.

 

The turntable era of Fisher products is a very different situation. Avery fisher sold the company in 1968 and from there the brand really got whored out for cheap massmarket products. Sanyo may have been the parent company and all production was moved overseas. Their tube amps from 1960 and on are a very different situation.

 

What do you mean by "the power knob has been busted in the on position?" If possible, I suggest you bypass the power switch.

 

I'd get the power knob fixed by a competent repairer asap, ideally as part of a full service.

 

I had something similar happen to me.

I bought a Decware EL34 based Torii Jr. from a member a few years back.

I had it on straight for a two or three days 24/7. I decided to give it a rest, so I switched it off. I went to turn it back on about 4-hours later and nothing.

I pulled out the fuse, which was in the power cord socket and it looked fine.

I put a meter on it just in case, and the continuity tested good.

There is just no power getting to it. I never got around to checking it out further, so it had been sitting on top of my sub woofer for a couple of years. I'm wondering, is there might be another fuse inside of the case? I don't know.

Since nothing lights up and everything was working perfectly four hours earlier, there is obviously nothing wrong with the amp, other than it is not getting any power, for what ever reason.

 

You're right. I don't know the skill level of @Dennis0675. The on/off switch failure is a very common problem on these old Fishers. Not uncommon at all to see the switch bypassed and a standard switch installed.
I use a variac with my Fisher amp. My Fisher's switch is always on and power is controlled with the on/off switch on the variac.

 

Check continuity of the switch.

 

That is my plan, I think it is very likely something other the the failed power switch. The failure of the power switch is that it doesn’t turn off the unit. It’s tough to believe that it would somehow change and turn off the unit from just sitting on a shelf.

 

If you mean that you’re using an inline switch on the power cord - a rocker-style or wheel-style switch - the little plastic actuator spring inside it may have failed. That’s a very inexpensive repair.

 

The Fisher 400 is now more than 50 years old, so if a part or two fails it shouldn't be a surprise. The power switch design was certainly not bad, but even Avery Fisher probably didn't expect his receivers to still be going after so long. The switches can eventually fail open, even in the on position, as seems to be your case.

However you power the unit, remember that the 400 was build when power was typically 115 V +/- 5V. Most power now is now 120 - 130 V. That extra voltage can stress parts by running them at the high end of their design range. It also means cold starts, especially after months in storage, can be extremely hard on aging electronics.

You can determine if the switch is the problem by bypassing it to see if the unit powers up. If you use a variac and take your time you should be able to determine if it is the switch or something else.

If it is the switch, switches can be rebuilt, but it is not a quick or easy task. They can be replaced (again not a quick and easy job), and there are both NOS and newer replacements, but the NOS switches aren't common and the replacement switches, while functional, don't always look the same.

If it isn't the switch, depending upon how extensive the rebuild was 10 or 15 years ago it may be time to consider another one. A regular rebuild that doesn't include iron is still much cheaper than another 400.

 

I’m talking about the actual volume knob that also turns the unit on and off. I’ve just been pulling the power cord to turn it off since it broke. Fixing that mechanism is apparently difficult because it’s hard to source the replacement part. It is a design flaw and every 400 will fail in this way if you use it. Most people will just use a switch at the power cord even if the knob is in good working order. This is what I was advised to do when I bought it but I’m a jackass and need to learn most lesson the hard way.

At this point is a backup for my backup amp. I don’t love the idea of putting a bunch of money in it but I feel obligated to do my part and keep it in good working order.

 

Fisher used a unique combination power/volume switch. The pot is a weak point of otherwise good design. The power section of the pot frequently fails and will not allow closing of the circuit to apply power. General remedy is to have a tech bypass the power section of the pot; IE rewire the connections so that the circuit is always "live" then use an AC cord power switch (as you were doing).

 

If it was a failure due to a cold start, shouldn’t something turn on and then fail? This was nothing, my first thought was my power outlet was on a blown circuit. Nothing lit up or made a hum for even a moment.