first power test issue [resolved]

illusineer · 679

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Offline illusineer

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on: September 07, 2020, 06:41:33 AM
Hi all, first time builder. I'm at this point in the manual where it says to plug it in and test the power inlet leads for their voltage, but the reading doesn't seem right. It is reading 0.768V plugged in.  Am I doing something wrong?
« Last Edit: September 09, 2020, 04:40:10 AM by Paul Birkeland »



Offline Paul Birkeland

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Reply #1 on: September 07, 2020, 06:43:37 AM
The "H" on your meter means "hold", which will not allow the value to change.  You need to hit the "Hold" button to get that to go away, then try again.

Paul "PB" Birkeland

Bottlehead Grunt & The Repro Man


Offline illusineer

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Reply #2 on: September 07, 2020, 06:59:40 AM
I did another test, it is reading around 0.378V plugged in when I test the inlet without hold on.
« Last Edit: September 07, 2020, 07:02:07 AM by illusineer »



Deke609

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Reply #3 on: September 07, 2020, 07:38:34 AM
Such a low AC voaltge reading makes me wonder whether you are taking the voltage between Neutral and Ground, rather than Live and Ground.  I'd double check that you're touching the probes to the correct IEC lugs.

If that's not it, I'd unplug the cord from the amp and test the AC voltage from the wall through the cord.

cheers, Derek



Offline Paul Birkeland

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Reply #4 on: September 07, 2020, 07:59:15 AM
Also double check that the fuse is installed and that it's installed into the correct part of the fuse holder (check the manual).

Paul "PB" Birkeland

Bottlehead Grunt & The Repro Man


Offline illusineer

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Reply #5 on: September 07, 2020, 08:42:51 AM
I tested with black on N and red on L. My fuse is installed in the lower part of the holder (not the backup fuse holder part), and it's in the inlet. The switch is on (dot in down position). With the plug partially inserted in the outlet (this is the only way I can read the outlet with my prongs) my meter reads 103.5V from the wall. idk what I'm missing.



Offline Paul Birkeland

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Reply #6 on: September 07, 2020, 08:46:22 AM
Test from N on the IEC module to the strip of metal across from the L/N tabs.

Paul "PB" Birkeland

Bottlehead Grunt & The Repro Man


Offline illusineer

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Reply #7 on: September 07, 2020, 09:34:41 AM
Test from N on the IEC module to the strip of metal across from the L/N tabs.

it reads 98V, what now?
« Last Edit: September 07, 2020, 09:59:07 AM by illusineer »



Offline monsterdonkey

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Reply #8 on: September 07, 2020, 10:16:41 AM
I don’t know the answer to your immediate question so I apologize for hijacking the thread, but:

I notice you haven’t written the terminal numbers on the mounting plate. Writing them on there will make the rest of the build (and subsequent troubleshooting) go more smoothly I’d bet.

I hope you get this first thing sorted out quickly. It’s usually just a bad solder joint or something like that.



Offline Paul Birkeland

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Reply #9 on: September 07, 2020, 10:30:09 AM
it reads 98V, what now?
Remove the fuse and test it with the continuity beep or impedance checker to be sure it's good.

Paul "PB" Birkeland

Bottlehead Grunt & The Repro Man


Offline illusineer

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Reply #10 on: September 07, 2020, 12:35:17 PM
Which terminals do I want to test and what am I looking for? Also how come my meter didn't read the voltage from L and N but it did from the strip?



Offline Paul Birkeland

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Reply #11 on: September 07, 2020, 03:37:10 PM
Which terminals do I want to test and what am I looking for?
Pull the fuse out and measure the resistance between the metal ends of the fuse.

Also how come my meter didn't read the voltage from L and N but it did from the strip?
An open fuse could do that, though most often that ends up being the fuse installed in the square spare holder rather than the little clip.

Paul "PB" Birkeland

Bottlehead Grunt & The Repro Man


Offline illusineer

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Reply #12 on: September 07, 2020, 05:22:03 PM
I tested the fuse, no reading on meter. I might have reversed the leads on the inlet yesterday and blown it, that's not good. Double checked and tested some other fuses for other equipment, they read fine, yep this ones blown lol.



Offline illusineer

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Reply #13 on: September 08, 2020, 06:09:24 PM
Update: I replaced the fuse with a 2a 250v one and the voltage reads out correctly with my new klein multimeter, I'm now past getting both sides of each tube to glow, I also realized that having an old junk multimeter that didn't work right was what lead me to somehow thinking it was OK to reverse the leads, moral is quality tools save you more time and money in the long run  8) , thanks for the help Paul! and yes I now have all the terminals marked on the chassis with a pencil