Bad IEC jack??

[crgolfer]

Is it possible that I have a bad IEC jack?  I have completed the Beepre construction and the resistance values check out but when I try the voltage check nothing.  I performed the voltage check during the 120 v input wiring and it was fine but now there is no voltages on even the inputs to the transformers (terminals 1 and 2).

I did a voltage check on the IEC jack and have no voltage between any of the three hookup lugs.  However when I test between the lugs and the metal strip beside them I get 122 volts.  Is it possible that some internal connection has broken? 

 

[johnsonad]

Did you check the fuse?

 

[crgolfer]

The fuse is good.

 

[Paul Birkeland]

  However when I test between the lugs and the metal strip beside them I get 122 volts. 

This would indicate a bad fuse, or a fuse that's out of position.

 

[Grainger49]

The fuse holder has a place for the fuse and a spare.  The key is learning which is which.  I put the fuse in the wrong place in my Seduction.  I got the same problem you seem to have.

 

[crgolfer]

I just checked and I now have a blown fuse.  I didn't think that this was the problem because the first thing that I checked was the fuse and it was good when I tested it with my mult-imeter.  I guess the the fuse was blown on my later attempts to discover the problem.  I will be off the radio shack for a supply of fuses.

 

[crgolfer]

I just discovered that I have a F1A fuse which is a fast blow type instead of the needed slow blow version. 

 

[johnsonad]

Yup, you're not the only one. I caught it and replaced it with a slow blow in my BeePre.

 

[Doc B]

Guys for what it's worth, we got some fast blos in from our supplier when we ordered slo blos. The fast blos might fail under startup surge, however I haven't had any problems here and I think most of the gear here has the fast blos, including a couple of BeePres (though they may have ended up with 1.5A fast blo fuses - PB may know).

In general if you are seeing fuses that look like they blew gently with a fair amount of the fuse wire still intact, a slo blo may fix the situation. Or a 1.5 A fast blo. If the fuse looks like it went violently, i.e. vaporized wire and with brown crud plastered on the inside of the glass, you may have a bigger problem downstream.

 

[Paul Birkeland]

At some point, our fuse supplier stopped distinguishing between the slow and fast blow fuses.  Consequently, we may need to find a different supplier, or determine if we can switch to fast blow fuses (I tend to use 3-5 A fast blow fuses in my non-kit builds, you can hear them snap when they blow, which is convenient).

 

[Paul Joppa]

Slow blow are more expensive, but better suited to tube gear in general. Usually a larger-value fast blow is needed relative to the minimum slow-blow value. Some things, such as shorted low-voltage windings, or excessive tube current, do not draw enough current to blow a larger fast blow fuse but may still allow damage to some components or tubes. It's not an easy call. None of the slow blow fuses are slow enough to really match the electronics, they are just "closer" to ideal - something between 0% and 100% but hard to say where ...

Sorry, not much help from technical details here.

 

[crgolfer]

I just inserted a slow blow fuse and that solved almost all of the problems.  I now have just one voltage reading which is off and is caused because I ruined a 10uf cap while soldering another connection.  I hadn't realized it but part of the soldering iron was in contact with the cap and burnt a nice gouge in the body.  I have ordered a replacement from Parts Express.