It is currently Tue Mar 17, 2020 2:33 am

All times are UTC - 7 hours



Post new topic Reply to topic  [ 13 posts ] 
Author Message
Post subject: 94 Twin power shuts off
Posted: Sat May 12, 2012 5:46 pm
Offline
Hobbyist
Hobbyist

Joined: Tue Jan 18, 2011 1:19 pm
Posts: 17
I just picked up a used Twin and after playing it fo a bit I put it on standby and came back to it about 20 minutes later and the light was off??? I thought maybe I had turned it off but it was still switched on but the power was out and could not be turned on....

Any idea what would cause this?

Thanks
Derek


Top
Profile
Fender Play Winter Sale 2020
Post subject: Re: 94 Twin power shuts off
Posted: Sat May 12, 2012 8:24 pm
Offline
Rock Star
Rock Star
User avatar

Joined: Sat Jul 03, 2010 2:18 pm
Posts: 6544
Sounds like solder or connector bug-a-boo strikes again! Rule those out before going any further. Unless you've worked under the hood where high voltages lurk.... may wanna seek a skilled tech.


Top
Profile
Post subject: Re: 94 Twin power shuts off
Posted: Sun May 13, 2012 3:03 am
Offline
Rock Icon
Rock Icon
User avatar

Joined: Fri Feb 05, 2010 4:31 am
Posts: 14050
Location: Province de Québec, Canada
Have you check the fuse ?

If bad, replace it by the same value , power ON and check if after fews minutes , or more , one of your 6L6 is too much bright = tubes failure.


Top
Profile
Post subject: Re: 94 Twin power shuts off
Posted: Sun May 13, 2012 3:58 am
Offline
Hobbyist
Hobbyist

Joined: Tue Jan 18, 2011 1:19 pm
Posts: 17
Thanks for the responses! I will take it back to a local tube amp specialist :) I had it there once when I first got it to have the tube replaced so the tubes have less than a few hours on them. I didn't know if it might be the output transformer of something?

Thanks,
d.


Top
Profile
Post subject: Re: 94 Twin power shuts off
Posted: Sun May 13, 2012 4:55 am
Offline
Rock Icon
Rock Icon
User avatar

Joined: Fri Feb 05, 2010 4:31 am
Posts: 14050
Location: Province de Québec, Canada
dschaaf wrote:
Thanks for the responses! I will take it back to a local tube amp specialist :) I had it there once when I first got it to have the tube replaced so the tubes have less than a few hours on them. I didn't know if it might be the output transformer of something?

Thanks,
d.


If the power tubes have been replaced without a new bias setting, this will shortened tube's life. If you are going to see the same tube "specialist " be carefull, ask him what he do with bias when replacing 6L6 last time.
But with the best tech and a good job, tube could fail on warranty
Be sure you see a real tube specialist like an electronic tech. They are usually not working in music store.


Top
Profile
Post subject: Re: 94 Twin power shuts off
Posted: Sun May 13, 2012 5:28 am
Offline
Hobbyist
Hobbyist

Joined: Tue Jan 18, 2011 1:19 pm
Posts: 17
Thanks stratele52,

The tech is a very well known custom amp builder for many "A" level artists as opposed to someone at a local store....but I will ask about the biasing. :)

Also, if it was bad tube would that cause the power light to out and the power to shut off?

Thanks,
d.


Top
Profile
Post subject: Re: 94 Twin power shuts off
Posted: Sun May 13, 2012 6:13 am
Offline
Rock Icon
Rock Icon
User avatar

Joined: Fri Feb 05, 2010 4:31 am
Posts: 14050
Location: Province de Québec, Canada
dshaft, do you check the amp fuse ? This question , the first I ask you is a must to begin to help you. Without this answer we can't go further.

No power = no power light= nothing work.

There could be many issue for no power , first thing check fuse. if fuse is blow this is because amp inside commponent draw too much current, power. Many times in tubes amp this is because one or more power tube is defective.

if fuse is good , are you sure ? Even fuse look good , could be bad. If fuse is good whe should check for bad solder inside amp , close to the power transformer circuit. This is probalbly an easy fix.


Top
Profile
Post subject: Re: 94 Twin power shuts off
Posted: Sun May 13, 2012 7:15 am
Offline
Hobbyist
Hobbyist

Joined: Tue Jan 18, 2011 1:19 pm
Posts: 17
Thanks again.

I will check that out first thing. I have the amp at my practice space so that is why I haven't confirmed that yet...but you are absolutely right. I will post what I find :)


Thanks,
Derek


Top
Profile
Post subject: Re: 94 Twin power shuts off
Posted: Tue May 15, 2012 3:44 am
Offline
Hobbyist
Hobbyist

Joined: Tue Jan 18, 2011 1:19 pm
Posts: 17
Ok, I got the amp back and have confirmed that the fuse is ok.

Now when I switch it on the light on the front does not come on but I can hear it humming and so I plugged in and switched on the standby and it does play....so maybe the light it just burnt out.

The thing that's strange is that the volume seems very low. On the clean channel if I turn up to 3 it's ok but not loud....(probably not 30% as loud as my Twin Reverb '65 RI on 3). I can easily turn the clean channel all the way up to 10 and play 2 feet in front of it. I have messed with the effects loops switch on the back and also the high/low power doesn't seem to have any effect at all.

Thanks,
d.


Top
Profile
Post subject: Re: 94 Twin power shuts off
Posted: Tue May 15, 2012 4:34 am
Offline
Rock Icon
Rock Icon
User avatar

Joined: Fri Feb 05, 2010 4:31 am
Posts: 14050
Location: Province de Québec, Canada
Ok pilot light is only burn and need a replacement and amp need a fix , Output tubes ? if you said the 25 watts ( Low power ) and normal have no effect. I hope you did not pay too much for this amp.

Find a good tech , somebody you know he is good.


Top
Profile
Post subject: Re: 94 Twin power shuts off
Posted: Tue May 15, 2012 5:32 am
Offline
Hobbyist
Hobbyist

Joined: Tue Jan 18, 2011 1:19 pm
Posts: 17
Thanks....I will take it to a good tech. Unfortunately I paid $1100, kind of on an impulse because I didn't need another amp (already had about 10 other higher end tube amps + the Twin Reverb '65 RI). Oh well, of all the used gear I have bought over the years this is the first one that hasn't worked out.

Thanks,
d.


Top
Profile
Post subject: Re: 94 Twin power shuts off
Posted: Tue May 15, 2012 8:02 am
Offline
Rock Icon
Rock Icon
User avatar

Joined: Tue Jun 29, 2010 1:20 pm
Posts: 9640
Location: Indiana
Can you see the heater glow on all tubes?

_________________
---> "The amp should be SWITCHED OFF AND UNPLUGGED before you do this!" <---

Por favor, disculpe mi español, no se llega a la práctica con mucha frecuencia.


Top
Profile
Post subject: Re: 94 Twin power shuts off
Posted: Tue May 15, 2012 8:10 am
Offline
Hobbyist
Hobbyist

Joined: Tue Jan 18, 2011 1:19 pm
Posts: 17
Thanks....I will check :)

D.


Top
Profile
Display posts from previous:  Sort by  
Post new topic Reply to topic  [ 13 posts ] 

All times are UTC - 7 hours

Fender Play Winter Sale 2020

Who is online

Users browsing this forum: No registered users and 2 guests


You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum

Search for:
Jump to: