Crack troubleshooting; IEC Inlet voltage [resolved]

[MikeZalewski]

Good evening everyone,

I recently ordered a bottle head crack 1.1, and have begun assembly a few hours ago. I just reached the step to test voltage through the IEC to determine what wiring i should go based on the voltage it is throwing out. This however, has led me to find a few issues. I plugged the power cord into the IEC, and was checking voltage. I got 5 volts from the reading, although when checking voltage on the two outmost female connectors on the power cord, i got 120 volts. Could it be the snap in switch that is causing an issue? the fuse is fine. I hope i am making a user error so that i can possibly fix it and continue my progression.

I just took the IEC out of the plate, and unsoldered the ground connection and the connection to the power switch. The IEC is still reading 3-5 volts based on where i am placing my leads on the prongs on the backside. I am indeed connecting the red and black leads correctly, that much i do know. I have already eliminated the possibility of it being the multi-meter, as i got the same reading on both of my fluke's.

Any help or assistance would be greatly appreciated.

[Paul Birkeland]

Could it be the snap in switch that is causing an issue?

Considering when you test the power line voltage the switch only has one wire soldered to it, it's out of the circuit.

the fuse is fine.

Can you post a photo of where you have the fuse installed?

I just took the IEC out of the plate, and unsoldered the ground connection and the connection to the power switch.

I would strongly advise against doing stuff like this.  Taking the IEC power entry module out of the plate doesn't help you in any way, but there is the risk that in the desoldering and removal process that you'll damage that part and then need to sit around and wait for a replacement.

[MikeZalewski]

Considering when you test the power line voltage the switch only has one wire soldered to it, it's out of the circuit.

Would you be able to emphasize on this a little more? i'm not quite sure what you mean. Here's a photo of the fuse in its location.

[Paul Birkeland]

Since you aren't testing the voltage at the switch, you would never know whether or not it functions.

Next I would try measuring the AC voltage between where the red wire hooks up on the IEC power entry module and the metal strip across the inlet from it that doesn't have a connector on it. 

[MikeZalewski]

I just took two different voltage tests, and now its down to .05 v from 5v AC. here are some photos.

[Paul Birkeland]

The red lead of your meter is not plugged into the correct hole.

[MikeZalewski]

My bad, i finally got a reading of 118 volts from the flat piece to the tab which the wire goes from. Am i good to go now?

[Paul Birkeland]

Yes.

[MikeZalewski]

Went ahead and started wiring a bit, although the PT-10 and the tubes have no power going to them. I have 0 volts coming out of the L & N tabs when the power switch is on, although when its off, i get around 2 volts. the strip underneath L & N is getting 116 still, though. What is the reason for this? Thank you for all the help

[Paul Birkeland]

That would be the description for a blown fuse.

[MikeZalewski]

Thank you for informing me! i just tested it on my multimeter and it's reading OL. It isnt blown, but it must just be faulty. Ill be looking around for another 250v fuse in my house. Is there any way to test anything without a fuse without risking any damage? I only get 120 through the plug.

[Paul Birkeland]

If it's OL, then it is blown.  They don't always blow the same way.  You just need a 1A-3A fuse, the voltage rating isn't particularly important. Do not, under any circumstances, try to bypass the fuse and run the amp.  Your local hardware store very likely has these fuses in stock.

[MikeZalewski]

I just found another one in my house which tests fine. Ill be back to let you know how things go.

[MikeZalewski]

Its fully assembled now, thank you for your assistance Paul.

All of my ohm readings have been accurate except for the one on terminal 6. Instead of reading 0, its reading around -4 to -6 ohms. I've re-soldered all of the areas to potentially eliminate that problem. Can you lead me in any direction?

Thanks again.

[Paul Birkeland]

Terminal 6 wires up to the headphone jack.  When there are no headphones plugged in, the jack shorts that connection across to the outside, then down to the ground at the bottom.  It is incredibly common to find that the black wires which meet at the headphone jack aren't all the way soldered.  It's easy to solder one and miss the other.  The weird resistance measurement suggests checking over that headphone jack very, very carefully.

If you can't find anything, I'd post some photos of the octal socket wiring and the HP jack wiring and we can look them over.

-PB