• WARNING: Tube/Valve amplifiers use potentially LETHAL HIGH VOLTAGES.
    Building, troubleshooting and testing of these amplifiers should only be
    performed by someone who is thoroughly familiar with
    the safety precautions around high voltages.

help! no power, im lost

jdbrocious

Member
2005-03-21 5:13 pm
PA
I am buiding a monoblock kit and i have checked all the connections, but I still have no power going through the unit. I can't even blow a fuse or anything. How/where do I start to trouble shoot. Here are some pics, most everything is soldered except where I had to extend some wires. The power switch and a few other things are just hanging out until I figure out what is going on. I do have a multimeter, but I'll i could figure out was that it was operating at 60 volts. Im new to this electrical stuff.

[IMGHTTPDEAD]http://www.audiokarma.org/gallery/watermark.php?file=4631[/IMGHTTPDEAD]
[IMGHTTPDEAD]http://www.audiokarma.org/gallery/watermark.php?file=4632[/IMGHTTPDEAD]
[IMGHTTPDEAD]http://www.audiokarma.org/gallery/watermark.php?file=4633[/IMGHTTPDEAD]
 

SY

diyAudio Moderator Emeritus
2002-10-24 10:19 pm
Chicagoland
www.SYclotron.com
Start with the line plug (unplugged!). Using an ohmmeter or a continuity checker, connect between each power cord prong and the transformer primary (switch "on"). If you have continuity, you've got a transformer issue. If you don't, then leave the ohmmeter lead connected to the power cord prong and with the other lead, start working back to the power plug until you find where the connection is lost.
 
Check your connectors

Hi
So you have mains going into the transformer?
And voltage coming out?
I second dsavitsk in recommending grommets. I am sure i can see one of the black wires been stripped as its scraped along the hole...a disaster waiting to happen.
I am not perfect but I dont like those dreadful crimp connectors.. i prefer solder and heat shrink for all and often use 2 or 3 layers of heat shrink.
Again I do not mean to criticise but some of your solder joints may be dry by the look of them
Good luck
Take it easy play it safe and methodical (read the safety directions)
Nick
 

jdbrocious

Member
2005-03-21 5:13 pm
PA
Re: Check your connectors

duderduderini said:
Hi
So you have mains going into the transformer?
And voltage coming out?
I second dsavitsk in recommending grommets. I am sure i can see one of the black wires been stripped as its scraped along the hole...a disaster waiting to happen.
I am not perfect but I dont like those dreadful crimp connectors.. i prefer solder and heat shrink for all and often use 2 or 3 layers of heat shrink.
Again I do not mean to criticise but some of your solder joints may be dry by the look of them
Good luck
Take it easy play it safe and methodical (read the safety directions)
Nick

one main from the transformer goes to the EIC, and the other to the fuse.

it must be completing a circuit because i show 60volts at all points along this path.

the wires are NOT scraped.... i will wrap them to be on the safe side until i find the grommets.

this is my first soldering job and i think my iron is way to weak, it takes forever to melt. Is there such thing as too much solder?? what does dry mean?
 
Try this

Go to here it seems a decent site
http://www.instructables.com/id/How-to-solder/
When you say 60 volts.. whats the volts at the power point? what are the ratings of the transformer?
As i found out a good soldering iron is essential if you are going to do this more. 700 to 800 degrees tip temp with enough mass to sink heat into things you are soldering. Most irons are for solid state. For tubes think binford.
Good luck
Nick
 

chrish

Member
2003-10-20 2:43 pm
Sydney
I can remember staying up till 2 in the morning trying to finish the wiring of a previous amp. Hooked up the multi-meter to check the B+ voltage and got something completely different to what I expected. Frustrated I went to bed thinking I had screwed something up completely. In the morning I re-checked, finding that I had the meter set to AC instead of DC when I had tried to check the voltage. Turns out I had not mis-wired anything, and the amp was fine.

My point is that it sounds like you are very new to this, so check that you set the multi-meter to read AC voltage from the mains to the transformer and also from the output of the transformer. After the rectifier you will need to set your multi-meter to DC to read the voltages.

Hope I have not been teaching you to suck eggs here, just trying to help, as 60 volts out of the mains is way wrong...

Chris
 
Re: try ac

duderduderini said:
There shouldnt be any dc on your mains so thats good
Pop it on "ac" if it isnt autoranging then select the appropriate scale
Try that

i get nothing on AC either...... just switched around the wiring so that the fuse is inline from the EIC to the switch.

so right now..

I have the "L" going directly the fuse. From the Fuse to the switch. From the switch to the black wire leading to the transformer. The other black wire from the transformer goes to the "N" on the EIC.

does this sound right??
 

Iain McNeill

diyAudio Moderator Emeritus
something very basic is wrong. you should see at least 115VAC. 60VAC sounds more like electric field coupling into the meter. Somethings open circuit here.

I notice there's a long protrusion on the L terminal of your IEC connector. Could it be another fuse?

Check continuity from the live pin on the outside of the case to the live pin on the inside.

This has to be something very simple that we're all overlooking.