IEC & Switch Issues

[DD84]

Hello,

First time builder here. I've been having issues with the IEC and switch, around page 23 or so of the Crack manual.

Testing L to N with the DMM gives me 1 volt/low voltage, as well as L to E. N to the metal tab that is unmarked on the diagram on page 20 gives me 120, and so does E to that metal tab. Line to the metal tab gives me 0. The switch gave me correct impedance readings, but after giving the unit power it doesnt do that anymore, so maybe 0 in both states, although it does pass the continuity test correctly.

When soldering the bare buss wire to the E tab on the IEC inlet, I heated that E pin a lot and it wiggled around a bit in the socket. Could this have created a shorted neutral type of situation? Also, when testing the unit out one last time for readings with the meter, it cut the power out on that outlet. Is this a faulty IEC socket?

Thanks.

[Paul Birkeland]

Do you have the fuse installed?  If so, is it in the clip, and not in the square hollow section?

[Doc B.]

Tripping your breaker is a sign that you need to unplug the amp, remove the power cord and sort things out before turning it on again.

Along with checking the fuse use your continuity tester to check that the center pin (E, ground) on the top side of the IEC jack is continuous with the chassis ground tab next to the IEC socket on the underside, or just to the chassis itself. If the E pin on the underside of the chassis or on the top side wiggles enough that the continuity reading cuts in and out you will need to replace the IEC jack. If it stays continuous (beeps or reads very low resistance) you are OK.

Make sure the power switch is switched to off. Verify this by testing for an open circuit across the power switch pins. Now go test resistance between L and N, L and E and N and E on the IEC socket. They should all read open with the power switch turned off. With the switch turned to the on position you should read some resistance between L and N, but L and E and N and E should still read open.

[Paul Birkeland]

The last time I had someone bring me a piece of gear that tripped the GFCI that easily, the neutral and the safety ground were wired together.