No Power

[phigits]

I am becoming a frequent poster and I’m just starting the build.

I have run into zero power when executing the first power supply test. I have tested as instructed at the 6.3 dc solder pads. No reading at all with the power switch in either position. The fuse is not blown. I also swapped out the power cord just to be sure. Finally I tested right at the power entry supply, still with no reading.

I’m assuming that the power entry supply is bad but I’d appreciate any advice on any further troubleshooting.

 

[Paul Birkeland]

I’m assuming that the power entry supply is bad but I’d appreciate any advice on any further troubleshooting.

You're the second person to suggest this in recent time, but this is nearly impossible.  In the last thread, the meter in question was not connected properly (the red probe was in the current reading position, not the voltage reading position).

I would suggest you start by using your meter to read the DC voltage of a fresh 9V battery (if you read 0V, don't throw the battery away!).  Once you've worked that out, then use your meter to read AC volts from your power outlet.

Once you've gotten that sorted out, then retry your measurements.  Do also review the photo in the manual showing exactly which part of the fuse holder the fuse rests in.

-PB

 

[phigits]

That's a really good suggestion and I will get a battery and do the test later today.  My meter has never failed me in any of my other builds but one thing I have not tested it recently.  I actually have a Crack kit waiting to be built so I was thinking about cannibalizing the power entry outlet just to save some time if I had to order a replacement.  I'm hoping there is a technical difficulty I am just missing and the battery test will surely prove that.

 

[2wo]

Double check that the fuse is installed correctly the holder has two positions one is for a spare ...John

 

[Paul Birkeland]

so I was thinking about cannibalizing the power entry outlet just to save some time

Please don't do this.  We have never had a failure of one of these modules, and the presumption that "this must be a bad part" will ultimately be what drains your time the most. 

 

[Doc B]

Where is the discussion of a continuity test through (from the input contacts to the output contacts of the conductors) the IEC power entry unit? Either it conducts or it doesn't.

 

[phigits]

I have not had a successful test - or any reading doing the tests that are outlined in the manual.  I have checked the fuse and the power cord but I have not: 1) double checked my meter on another source - I will do the battery test, 2) really checked to make sure the fuse is in the right slot.

I will do both of these tests when I get home this evening.  I'm just surprised at getting nothing to register on the meter so it must be user error if the part is not damaged.  I will followup with the results when I'm able to test again.

 

[Deke609]

What Doc B.said: continuity tests are a simple and safe way of testing both the fuse and the IEC inlet.

(1) Disconnect the power cord from the amp (and while you're at it, from the wall as well to be doubly safe)

(2) Set your meter to continuity -- usually a volume or sound-waves symbol like this: )))) -- test with a piece of scrap wire or lead cut-off: put a lead on each end and the meter should beep or produce a steady tone

(3) Test fuse - remove the fuse and put a lead on each end -- if you hear a beep or tone it is conducting

(4) Test IEC - put the fuse in the correct holder (or try both positions if not sure) and connect one lead to +ve on the IEC and one to -ve, then flick the switch: with the switch in the on position, you should hear the same beep or tone

 

[phigits]

1) ran the battery test with my meter - success.
2) ran the continuity tests - success.
3) checked the fuse - fail!  Operator error I had the fuse in the "backup position.  I should have known better...

All meter tests check out from there.  I feel like a bit of an idiot.  OK, a full bore idiot.  But better educated now. 

Thanks to all.

 

[Paul Birkeland]

We all make mistakes, that's why we are here! 

 

[Doc B]

Yup, the whole point of building these kits is that you come away with more knowledge about how this stuff works rather than just gratifying an urge to own the latest audio farkle. And we don't even charge extra for the educational aspect.  Every day I am in the lab with the guys we are all trying new things, having failures and learning from it.

 

[phigits]

Well, you guys are doing a great job. I’m a software guy by trade so I find learning how this stuff works as well as how to trouble shoot incredibly interesting as well as gratifying. I continue  trying to recruit friends to buy kits so I can continue building and learning.