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    Help! Fried my ST70

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    vanity

    Posts : 7
    Join date : 2011-01-12

    Help! Fried my ST70

    Post by vanity on Sat Mar 15, 2014 9:11 am

    Embarassed I took my ST70 round to a mates house. When I reinstalled it I must have accidentally nudged the on/off switch to ON  Evil or Very Mad . When I powered it up I heard a groan from somewhere within the amp and and none of the valves lit up.  Sad  Sad  Sad 
    I've taken a look at the fuse and, unfortunately, it seems fine so I've obviously caused something more expensive to go pop. Where should I start looking and how deep will I have to dig into my wallet to put it right?

    Bob Latino
    Admin

    Posts : 2411
    Join date : 2008-11-26
    Location : Massachusetts

    Re: Help! Fried my ST70

    Post by Bob Latino on Sat Mar 15, 2014 10:49 am

    Check that the power switch is OK .. Try bypassing the power switch with a jumper wire between the two terminals on the power switch. If that doesn't make the tubes light up check to see that the two black wires from the power transformer are still connected > one to the power switch and one to the fuse post.

    If that doesn't make the tubes light up AND your fuse is good then (and I hope this is not the case) the power transformer could be bad ?

    Bob

    Guest
    Guest

    Re: Help! Fried my ST70

    Post by Guest on Sat Mar 15, 2014 11:06 am

    did you smell anything 'burnt' at all? Are there any obvious signs that a component has overheated?
    Do a good overall visual check of all wiring under the chassis, have you got a multi meter handy? Check to see if you got any filament voltage from the main transformer.

    frank

    Posts : 95
    Join date : 2011-02-14
    Location : Pacific Northwest

    Re: Help! Fried my ST70

    Post by frank on Sat Mar 15, 2014 11:17 am

    Hi Vanity,

     I don't really know what you meant by "I've taken a look at the fuse". If you mean that literally, it might not be a good enough procedure. Sometimes they can blow and the visible part can still look good. Check it with an ohmmeter, or maybe you can flick the glass and look at the wire to see any vibrations.

     I'm certainly no expert (or even novice), but I don't think the fact of plugging it in with the power switch on would be any different than just turning it on with the switch. My guess would be that when the amp was plugged in, the preamp's volume control was not turned all the way down. This could result in blowing the rectifier tube (ask me how I know).

    I hope you will get your ST70 up and running soon.

    I hope this helps, but I posted in the hope the knowledgeable types found here will grade my answer.

    Guest
    Guest

    Re: Help! Fried my ST70

    Post by Guest on Sat Mar 15, 2014 11:20 am

    fswidecki wrote:Hi Vanity,

     I don't really know what you meant by "I've taken a look at the fuse". If you mean that literally, it might not be a good enough procedure. Sometimes they can blow and the visible part can still look good. Check it with an ohmmeter, or maybe you can flick the glass and look at the wire to see any vibrations.

     I'm certainly no expert (or even novice), but I don't think the fact of plugging it in with the power switch on would be any different than just turning it on with the switch. My guess would be that when the amp was plugged in, the preamp's volume control was not turned all the way down. This could result in blowing the rectifier tube (ask me how I know).

    I hope you will get your ST70 up and running soon.

    I hope this helps, but I posted in the hope the knowledgeable types found here will grade my answer.

    good point about the fuse, check it with a meter, can't really tell sometimes with fuses just by looking at them.

    Guest
    Guest

    Re: Help! Fried my ST70

    Post by Guest on Sat Mar 15, 2014 11:22 am

    on a totally separate note, since when do we have these annoying ads on these pages, the one I get up blocks half the message and I cannot seem to delete it!

    Bob Latino
    Admin

    Posts : 2411
    Join date : 2008-11-26
    Location : Massachusetts

    Re: Help! Fried my ST70

    Post by Bob Latino on Sat Mar 15, 2014 1:04 pm

    This is a FREE forum and, as such, you will get some ads coming up now and then ...

    Bob

    Guest
    Guest

    Re: Help! Fried my ST70

    Post by Guest on Sat Mar 15, 2014 2:02 pm

    I don't have a problem with ads, I do have a problem when they block part of the messages.
    fswidecki, I will try that, thanks.

    jjones3318

    Posts : 57
    Join date : 2011-04-05
    Location : Boulder, CO

    Re: Help! Fried my ST70

    Post by jjones3318 on Sat Mar 15, 2014 4:38 pm

    They did on Safari too, but are now back at the top where they should be, not over the top of posts.


    sKiZo

    Posts : 1310
    Join date : 2013-04-01
    Location : Michigan USA

    Re: Help! Fried my ST70

    Post by sKiZo on Sat Mar 15, 2014 7:56 pm

    All this talk about adds blocking the topic seem to be blocking the topic ...  geek 

    Back to which ...

    Were there no speakers connected when you powered it up? Das verbotin on tube gear, and can cause some serious damage. Just start backtracking looking for burn marks or bulges and hope it's not the big iron ...

    And no ... I don't have any ad issues here using Chrome ...

    Guest
    Guest

    Re: Help! Fried my ST70

    Post by Guest on Mon Mar 17, 2014 9:04 pm

    sooooooo....has this been solved??

    maz

    Posts : 9
    Join date : 2013-12-30

    Re: Help! Fried my ST70

    Post by maz on Wed Mar 19, 2014 12:00 pm

    As a newb here;
     
    I was wondering what the OP did wrong that caused this issue? (So I don't do the same)
    He turned the switch on, and fried it...? Or, did it just happened to fry at his friend's house??
    From his wording, it seems to imply that something procedural was done incorrectly?

    sKiZo

    Posts : 1310
    Join date : 2013-04-01
    Location : Michigan USA

    Re: Help! Fried my ST70

    Post by sKiZo on Wed Mar 19, 2014 1:49 pm

    MontanaWay wrote:sooooooo....has this been solved??

    What ... the popup ad problem?   Very Happy 


    Bob Latino
    Admin

    Posts : 2411
    Join date : 2008-11-26
    Location : Massachusetts

    Re: Help! Fried my ST70

    Post by Bob Latino on Wed Mar 19, 2014 2:36 pm

    What happened was that one of the ads (The Mars Bar ad only) was scripted wrong. Instead of appearing ABOVE the purple bar near the top of the Forum web page, it appeared covering the first couple of stickys lower on the page.

    Bob

    deepee99

    Posts : 1333
    Join date : 2012-05-23
    Location : Wallace, Idaho

    Apropos of absolutely nothing

    Post by deepee99 on Thu Mar 20, 2014 10:14 am

    If you throw an Idahoan and a Montanan off the top of a building at the same time, who hits the ground first?
    The Idahoan, because the Montanan gets lost.
    That annoying Milky Way ad has learned its manners, at least in Firefox and Chromium.

    Guest
    Guest

    Re: Help! Fried my ST70

    Post by Guest on Thu Mar 20, 2014 10:56 am

    deepee99 wrote:If you throw an Idahoan and a Montanan off the top of a building at the same time, who hits the ground first?
    The Idahoan, because the Montanan gets lost.
    That annoying Milky Way ad has learned its manners, at least in Firefox and Chromium.

    waddaya mean we get lost.......um....where am I again?????

    deepee99

    Posts : 1333
    Join date : 2012-05-23
    Location : Wallace, Idaho

    Re: Help! Fried my ST70

    Post by deepee99 on Thu Mar 20, 2014 11:36 am

    MontanaWay wrote:
    deepee99 wrote:If you throw an Idahoan and a Montanan off the top of a building at the same time, who hits the ground first?
    The Idahoan, because the Montanan gets lost.
    That annoying Milky Way ad has learned its manners, at least in Firefox and Chromium.

    waddaya mean we get lost.......um....where am I again?????

    You're just a bit west of Idaho, and slightly above the Arctic Circle, I think . . .


    Last edited by deepee99 on Thu Mar 20, 2014 11:37 am; edited 1 time in total (Reason for editing : geography)

    Guest
    Guest

    Re: Help! Fried my ST70

    Post by Guest on Thu Mar 20, 2014 11:39 am

    deepee99 wrote:
    MontanaWay wrote:
    deepee99 wrote:If you throw an Idahoan and a Montanan off the top of a building at the same time, who hits the ground first?
    The Idahoan, because the Montanan gets lost.
    That annoying Milky Way ad has learned its manners, at least in Firefox and Chromium.

    waddaya mean we get lost.......um....where am I again?????

    You're just a bit west of Idaho, and slightly above the Arctic Circle, I think . . .

    DAMN!..........need to get a better GPS!!

    anbitet66

    Posts : 132
    Join date : 2009-12-23
    Location : Valley Stream, NY

    Re: Help! Fried my ST70

    Post by anbitet66 on Thu Mar 20, 2014 12:27 pm

    Guys,

    What ads are you talking about???

    Recently, all I see is a little empty white box!  Maybe someone can fix the internet so I can get my nice comfortable ads back?  NOT!

    deepee99

    Posts : 1333
    Join date : 2012-05-23
    Location : Wallace, Idaho

    Re: Help! Fried my ST70

    Post by deepee99 on Thu Mar 20, 2014 3:18 pm

    anbitet66 wrote:Guys,

    What ads are you talking about???

    Recently, all I see is a little empty white box!  Maybe someone can fix the internet so I can get my nice comfortable ads back?  NOT!

    Fix the Internet? Only Skizo is capable of a venture this vast. But I worry about him, his design plans for the R-3350 VTA radial turbo compound amplifier are hopelessly behind schedule. This is the beta version:
    http://vimeo.com/36975300
    Maybe the exhaust gas got the best of him. Inquiring minds want to know . . .

    Guest
    Guest

    Re: Help! Fried my ST70

    Post by Guest on Sat Mar 22, 2014 11:12 pm

    so I guess we never have found out if the op has fixed his problem........

    frank

    Posts : 95
    Join date : 2011-02-14
    Location : Pacific Northwest

    Re: Help! Fried my ST70

    Post by frank on Sun Mar 23, 2014 1:39 pm

    MontanaWay wrote:so I guess we never have found out if the op has fixed his problem........

    It it too early to guess, or will this remain one of life's mysteries?

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