Trouble powering up

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JamesO
Posts: 156
Joined: Thu Mar 29, 2007 10:32 pm

Trouble powering up

Post by JamesO »

Hi everyone

I've been working on this D'Lite based amp for a few weeks and have been having trouble powering it up. I'm not registering any AC on my multi-meter when I touch the upper right prong of the IEC that the black primary's wired to when I flip the main and standby on. However, when I plug in the bulb limiter, the bulb does flash on and dim to nothing when I flick on the standby. I was hoping I could get some help figuring this out. I've traced my wiring and compared to the layout twice now.

[img:700:525]http://languagepool.net/amp/images/IEC3.jpg[/img]

[img:700:467]http://languagepool.net/amp/images/switches3.jpg[/img]
mlp-mx6
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Re: Trouble powering up

Post by mlp-mx6 »

We need a "broader" picture to see what you have.

What it LOOKS like is a tight loop that never connects to the power xfmr. Can you post a broader shot picture of all the power connections?

Also - you have the fuse connected backwards - the idea is to have the wall voltage connected to the BACK of the fuse - furthest away from where you would put the fuse in the hole. One side of your power xfmr "primary" wire goes to the other fuse terminal. The other wire coming in goes to your switch on one terminal and the other "primary" wire on the other switch terminal.
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bnwitt
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Re: Trouble powering up

Post by bnwitt »

Right off the top I see that you have your common terminal of the IEC connected to the fuse (with the blue wire) and the hot leg (the black wire) goes to the power switch. From the power switch the hot leg then goes to the other terminal of the fuse. That means the fuse itself is a direct short between hot and common with no load and I would imagine the fuse blows when you turn on the switch.

The common wire from the IEC should go directly to the "0" wire of the primary of the transformer with the wire from the fuse (where the blue wire is now) going to the 120 volts (or whatever your country's voltage is) leg.

In best practice, I would take the IEC hot terminal straight to the main fuse, out of the fuse to the power switch and then out of the switch to the PT's primary voltage leg.
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JamesO
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Re: Trouble powering up

Post by JamesO »

The two black wires are the primarys.

[img:700:525]http://languagepool.net/amp/images/powerSection2.jpg[/img]
JamesO
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Joined: Thu Mar 29, 2007 10:32 pm

Re: Trouble powering up

Post by JamesO »

Thanks guys. I'm going to take a few more minutes to think through what you're saying. This is the wiring diagram I went from. I wired it just like the diagram. But maybe I've looked at my wiring so many times now I'm not seeing a glaring mistake I made? I don't have a bulb, so there's no bulb wire.

[img:1167:339]http://languagepool.net/amp/images/wiring.jpg[/img]
mlp-mx6
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Re: Trouble powering up

Post by mlp-mx6 »

Would you please explain the flow of the RED wires that come from your power xfmr.

They SHOULD go to the rectifier board mounted on the side of the amp, at the "bottom" of the diode strings, The B+ should then come from the "point" of the diodes to the standby switch where you labeled it B+.
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JamesO
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Re: Trouble powering up

Post by JamesO »

Definitely. The red with yellow stripe goes to ground. The other two go to the rectifier board. The green with yellow stripe also goes to ground.

[img:650:488]http://languagepool.net/amp/images/biasFront.jpg[/img]

[img:700:364]http://languagepool.net/amp/images/biasSide.jpg[/img]

[img:600:410]http://languagepool.net/amp/images/biasBack.jpg[/img]
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brownnote
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Re: Trouble powering up

Post by brownnote »

From what I can see the PT is wired correctly at this point.
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brownnote
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Re: Trouble powering up

Post by brownnote »

From what you said before on the BN forum, I don't think you're getting accurate test readings...I responded over there.
Describe the current symptoms...it's not still blowing fuses right?
Remember kids...Always adjust for minimum smoke!

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JamesO
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Re: Trouble powering up

Post by JamesO »

Right - the fuses aren't blowing any more. I hope you don't mind me posting over here. I thought the more heads the better.

I had been metering incorrectly and Moss got me on track. Following his instructions, when I put one probe on each side of the IEC, there was no AC reading. When I put one probe on one primary and one on the other, there was also no AC reading.
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brownnote
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Re: Trouble powering up

Post by brownnote »

Try this...check your AC line voltage of your home with your meter.

Is sounds like your meter is the culprit, and checking the AC voltage of a plug in your house will tell you if it's working.
Remember kids...Always adjust for minimum smoke!

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JamesO
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Re: Trouble powering up

Post by JamesO »

That was it. My meter was bad. My voltages are all checking out now. :?
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