Bottlehead Forum
Bottlehead Kits => Crack => Topic started by: jamesondrums on May 28, 2020, 09:26:02 PM
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My voltage readouts are not right and my led's are not working. Not sure what to do from here. My voltages read
1. -1.2mv
2. -1.2mv
3. 0mv
4. -1.2mv
5. -1.2mv
6. 0mv
7. 4.6mv
8. 0mv
9. 12.9mv
10. 0mv
Any help would be greatly appreciated
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Three easy things to check:
(1) check that the fuse is (a) inserted in the correct position (the lowest one; the upper position is just a storage space for an extra fuse), and (b) not blown;
(2) make sure your meter is set to measure DC volts (V with a flat and dashed line), NOT AC volts (V with a wavy line); and
(3) make sure that the tubes are inserted and the amp is powered on.
cheers, Derek
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Checked all those off the list, same problem :/
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You could measure incoming AC voltage at the IEC inlet -- between Live and Neutral. And then do the same thing at the switch. If you've got line voltage at the IEC inlet, but nothing at the switch, you may have melted the switch.
cheers, Derek
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That seems to be working fine as well. I went through and checked all my wiring with the manual and checked my joints. All looks okay to my untrained eye haha.
- James
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One thing I did do that I am now remembering is: plug the bigger tube in the wrong direction and then powered it on during the "glow test" I noticed it, fixed it, and then it started glowing. Could that have done anything?
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And here's a picture of it just in case this helps.
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Is your meter set on DC voltage? If it's set to AC, you will get weird readings.
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It is set to DC. And the LED's are not lighting (unless they are super super dim and I am just not seeing it). I went through and checked my joints and add more solder to questionable ones as well.
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Made a mistake on my first post, everything is reading at V not mV
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What is the AC voltage between 18 and 19?
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I'm getting 172.6V between 18 and 19
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DC voltage between 20 and 21?
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I'm getting -.89V DC
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It looks like you've got one diode of each diode pair going the wrong direction (one pair between transformer and terminal strip, the other on the outside of the terminal strip). The silver bands of each pair should be facing opposite directions. See pages 38-39 of the manual.
cheers, Derek
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You're 100% correct. I'll fix it and get write back shortly.
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Switched it, when I first plugged it in it read 1V, then it went down to .89V then .77V DC
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And also still no LED
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Gosh I'm sorry, I had two backwards. Fixed that and it's sitting right at .4mV, still no LED
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A new overhead pic of the transformer and surrounding terminals with a clear view of the diodes might help.
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Forgive the messyness, I don't have a way to remove solder at the moment so soldering those diodes back on was a struggle and a half
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I would recheck the AC voltage again between 18 and 19, just to be sure that's still OK. If you have ~160V AC at 18 and 19, but 0V DC at 20 and 21, then it's possible that your diodes didn't survive the backwards installation and will need to be replaced.
(Also the LEDs will not light up unless the high voltage power supply works)
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Well, I just tried to check but then noticed I wasn't getting any reading because the fuse blew, so not 100% sure what happened there. I'll get replacement parts and repost once it's done. Thanks for the help.