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Hoffman Amps Forum image Author Topic: AC15HW1 power issue  (Read 2752 times)

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Offline Travis8

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AC15HW1 power issue
« on: September 14, 2023, 03:13:08 am »
Hi... my ac15hw1 doesnt turn on, no light on bulb or tubes..

I check fuses and looks ok, could be the rectifier? how can I check it?

thank

Offline Latole

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Re: AC15HW1 power issue
« Reply #1 on: September 14, 2023, 04:29:05 am »
No power on led glow ? It directly connected to the Power transformer 6.3 volts secondary winding.

Check power transformer primary and secondary voltage
How do you check fuse ? There are many fuses.  You must use a meter, not eyes .

Did you check internal fuse ? FS 1  ?

« Last Edit: September 14, 2023, 07:22:16 am by Latole »

Offline Travis8

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Re: AC15HW1 power issue
« Reply #2 on: September 14, 2023, 05:11:50 am »
No power on led glow ? It directly connected to the Power transformer 6.3 volts secondary winding.

Check power transformer primary and secondary voltage
How do you check fuse ? There are many fuses.  You must use a meter, not eyes .

Did you check internal fuse ? FS 1  ?

Schematic here ; https://el34world.com/charts/Schematics/files/Vox/Vox_ac15htvh1_handwired.pdf


I check the 3 fuses all look ok, no light from led.

I see right now that SL22 is disconected from one leg. Could be the issue?

Offline HotBluePlates

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Re: AC15HW1 power issue
« Reply #3 on: September 14, 2023, 06:20:07 am »
I see right now that SL22 is disconected from one leg. Could be the issue?

Correct AC15HW1 schematic

Yes.

SL22 connects from the fuse F4 to one side of the power switch.  With it open, no power can flow into the amp.

Some may choose to disconnect the thermistor SL22, but if so there must be some kind of jumper wire across it to complete the now-open connection.

Offline Loomer

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Re: AC15HW1 power issue
« Reply #4 on: September 14, 2023, 06:24:16 am »
I check the 3 fuses all look ok, no light from led.

I see right now that SL22 is disconected from one leg. Could be the issue?

"Look ok" as in "buzz for continuity with a DMM"?

It might be my bad, but I can't seem to be able to locate SL22 on the schematic?

Offline sluckey

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Re: AC15HW1 power issue
« Reply #5 on: September 14, 2023, 06:44:38 am »
It might be my bad, but I can't seem to be able to locate SL22 on the schematic?
Look at the link posted by HBP. Latole posted a wrong schematic.
A schematic, layout, and hi-rez pics are very useful for troubleshooting your amp. Don't wait to be asked. JUST DO IT!

Offline Latole

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Re: AC15HW1 power issue
« Reply #6 on: September 14, 2023, 07:23:27 am »
[
Look at the link posted by HBP. Latole posted a wrong schematic.
[/quote]

Sorry , I update my post

Offline Latole

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Re: AC15HW1 power issue
« Reply #7 on: September 14, 2023, 07:24:30 am »
To me "look" ok and are ok is not same thing.

 


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