Fet Valve 500 Amp (Older Version) Power Button Light Not Lighting Up

TjMV3 · « **on:** 21 Sep 2008, 02:18 pm »

Hi guys.

I've had this amp up and running for the last three days and it has been working flawlessly. Sounds very, very good. Runs dead quiet.

But this morning when I powered up (CD Player first, Pre Amp second and then Amp) the small light on the power button didn't light up. When it did not come on, I powered everything off (in reverse), waited a about a minute or two and then powered up again. Still no light on the power button.

I can't tell if the amp is powered up and it's just the little power light that may be out. Or if the amp itself isn't working at all (not receiving any power), right now. This amp is so dead quiet and the chasis only starts to get warm after it's been playing for a few hours. I tried putting my ear next to the tweeter but I can't hear anything. But I could barely hear anything from the tweeter when I did that the other day. This thing is so dead queit. Which I think is a great thing. But in this situation, I'm uncertain.

I still have all the components powered up, right now. Including the amp (still no power light indicator).

I'm thinking of putting a CD into the Rega Apollo and playing it ( to see if it's just the power light indicator that's out); and to see if it plays through the speakers. But I'm afraid to do that.

If the amp is completely out and not getting power, would my trying to play a CD cause damage to the amp or other components or maybe even start a fire?

Is it okay to put a CD in and press play, just to see if the music comes through?

It's Sunday morning and I don't want to bother Frank on a Sunday....or at this time of morning.

Thanks.

martyo · « **Reply #1 on:** 21 Sep 2008, 02:25 pm »

I would just give it a try.

JerryM · « **Reply #2 on:** 21 Sep 2008, 02:32 pm »

Quote from: martyo on 21 Sep 2008, 02:25 pm

I would just give it a try.

I would too. If you have lost the main 15 amp fuse inside the amp, it is not really powered on at all. Give it a try.

Just remember that if you intend to change a fuse, make sure the amp is unplugged, and has been for about an hour. This will ensure that you don't get zapped by a power supply that is not fully decayed.

Good luck,

Jerry

TjMV3 · « **Reply #3 on:** 21 Sep 2008, 03:16 pm »

Thanks guys.

I tried it. No sound , whatsoever.

I unplugged the power chord from the wall oulet and I'm going to wait a good hour or two before checking the fuses.

Should I unplug the pre amp and Cd Player from their power outlets, too? Or can I leave them plugged in?

Just want to make sure I don't screw something up or get zapped. Since I'n not all that technically or electrically knowledgeble, I always take the safe approach. Even if it comes off a little over-cautious or paranoid, to those who are knowledgable.

JerryM · « **Reply #4 on:** 21 Sep 2008, 03:33 pm »

I would make sure the amp is completely disconnected from any source. If you change a fuse, make sure to use the correct fuse, i.e. slow blow with slow blow, quick blow with quick blow. The ampere ratings must be followed as well.
If, after replacing the offending fuse the fuse blows again, call Frank. That is a clear indication that something is amiss.

Jerry

sueata1 · « **Reply #5 on:** 21 Sep 2008, 03:48 pm »

If ya have a multimeter it's great for checking continuity of the fuses,,,,
the fuse might appear to be ok visually but could have minute break at the ends,,,or in the middle
if this is the case just replace as this is a indication that they failed from just old age,,,

if on the other hand the filament is gone (totally vaporized) you probably have a Dead Short circuit in the amp

hope ya can figure it out...good luck

mel

Tom Alverson · « **Reply #6 on:** 21 Sep 2008, 03:51 pm »

I have the same older Fet-Valve amp and my power switch is a little flakey now. If I flip it on and off a few times it eventually comes on (the switch lights up). Once I got it to turn on this way I just plugged the amp into a switchable power strip and I use that to turn it on and off.

Tom

TjMV3 · « **Reply #7 on:** 21 Sep 2008, 03:53 pm »

Okay, will do. I'll disconnect everything including the speaker cables, take the amp out of the rack and place it on the table.

I'll have to call Frank to get the correct info on the fuses, because I bought this second hand and I don't have the owner's manual for reference on the correct type and value of the fuses.

Just feel weird calling Frank on Sunday, so I'll probably wait till tomorrow.

The thing that has me concerned is that these fuses are brand new and were just installed, when I had him put it up on the bench and the amp checked out. Frank said all it needed was a rebias because for some reason the bias was set too high and they had to replace the fuses. The previous owner had incorrect value/spec fuses in this.

I'm worried that something else is wrong, here. Is it possible a bad tube could be causing this?

Thanks again, Jerry.

Wayner · « **Reply #8 on:** 21 Sep 2008, 03:55 pm »

I believe you may have lost a fuse. The illuminated switch "light blub" has nothing to do with the switch function. If the bulb is burnt out the switch will still work. If you get no power, a fuse has been blown. Fuses do "just blow" once in a while from age or stress. Replace with same type and rating.

Wayner

TjMV3 · « **Reply #9 on:** 21 Sep 2008, 03:56 pm »

Quote from: sueata1 on 21 Sep 2008, 03:48 pm

If ya have a multimeter it's great for checking continuity of the fuses,,,,
the fuse might appear to be ok visually but could have minute break at the ends,,,or in the middle
if this is the case just replace as this is a indication that they failed from just old age,,,

if on the other hand the filament is gone (totally vaporized) you probably have a Dead Short circuit in the amp

hope ya can figure it out...good luck

mel

I don't have a multimeter and don't know how to work one. I'll have to buy one and learn how to use it.

Thanks.

Wayner · « **Reply #10 on:** 21 Sep 2008, 04:00 pm »

Just unplug the amp from the wall outlet and take the fuses out from the back. Look at them and see if you can see the wire in the glass tube broken. Another sign can be some black soot like looking stuff inside the fuse barrel.

Wayner

TjMV3 · « **Reply #11 on:** 21 Sep 2008, 04:02 pm »

Quote from: Wayner on 21 Sep 2008, 03:55 pm

I believe you may have lost a fuse. The illuminated switch "light blub" has nothing to do with the switch function. If the bulb is burnt out the switch will still work. If you get no power, a fuse has been blown. Fuses do "just blow" once in a while from age or stress. Replace with same type and rating.

Wayner

I hope that's all it is. I'm praying that's all it is

The troubling aspect is that these fuses are all new. But yeahm fuses do blow and it doesn't neccessarily mean there's anything else wrong. Maybe I'm worrying too much.

I just got this amp and I really love the sound. I can only imagine how great the current Fet Valve 500 sounds. Going by the sound of this one, I'll be getting a new one....some time in the near or not too distant future. Wonderful sounding amp and it really has a nice synergy with my pre amp and CD Player.

Wayner · « **Reply #12 on:** 21 Sep 2008, 04:06 pm »

Because the light in the switch does not come on (and I doubt the lamp in the switch is out), is why I suspect the fuses. Even new fuses can blow. Just go get some new fuses. It is the main power fuse.

I sure Frank will chime in at some point here this morning.

Wayner

Wayner · « **Reply #13 on:** 21 Sep 2008, 04:16 pm »

I think the main fuse is inside the cabinet. The power cord should go to it and then to the switch.

TjMV3 · « **Reply #14 on:** 21 Sep 2008, 04:31 pm »

Fuses on the back of the amp both look fine...intact.

Major concern.......I the RCA jacks are all loose and wobbly. I think I may have broken them. I'm using Cobalt Cable interconnects and they have those locking RCA barrels. They are a major hump to loosen up and I think I may have broken the RCA inputs

I was trying to be very careful, but I think I screwed up.

After this, no more locking RCA plugs for my amps!!!!

Any who, I'm opening her up and taking a look at the inside fuses.

TomW16 · « **Reply #15 on:** 21 Sep 2008, 04:37 pm »

I had loose RCA jacks on my FetValve 350. When you open your amp, simply tighten the nut on the inside. If the wire's are still soldered on securely, you're likely OK.

Good luck.

Tom

TjMV3 · « **Reply #16 on:** 21 Sep 2008, 04:42 pm »

I unscrewed/removed all the screw of the top chasis, but this thing won't come off. Is there some trick to getting this off? I thought all I had to do was slide the chassis cover towards the front of the amp/faceplate and it would copme off. But it's not moving more than a teeny-weeny hair.

Wayner · « **Reply #17 on:** 21 Sep 2008, 04:44 pm »

The are screw on the sides, too.

TjMV3 · « **Reply #18 on:** 21 Sep 2008, 04:50 pm »

I got it off.

There were four more screws (two on each side) that were on what I thought was a seperate panel. But apparently they are connected together by those four screws.

Peeking inside, now.

TjMV3 · « **Reply #19 on:** 21 Sep 2008, 05:09 pm »

The two fuses that are together in the side/middle of the chasis look fine. I don't see any breaks.

But the lone fuse (Buss MDA 10) that sits right next to that huge transformer, has a white body to it. Looks like it's made out of some kind of plastic or ceramic or something. It's not see through. So I have no idea how to determine whether this Buss MDA 10 is bad or not.

This is what it looks like....

http://www.overniteelectricsupply.com/mall/morea.asp?ProdID=20284

Anyone have any idea how to check it?

Did I mention that the transformer is HUGE?

Wow!

I'm going to attempt to tighten the RCA input jacks. Wish me luck