BeePre2 - filament voltage power supply

Yossihaimberg · 256

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Offline Yossihaimberg

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on: February 18, 2025, 06:37:50 AM
When I’m checking the filament voltage power supply, I’m reading only 1.2 volts (supposedly should be 6.3 volts).

What do I do????


Offline Paul Birkeland

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Reply #1 on: February 19, 2025, 05:34:53 AM
Can you post some photos of your build so far? Can you measure the AC voltages coming into the board from the power transformer?  Are all the capacitors installed in the correct orientation? (and the rectifier diodes?)

Paul "PB" Birkeland

Bottlehead Grunt & The Repro Man

Offline Yossihaimberg

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Reply #2 on: February 19, 2025, 06:47:30 AM
Here are the pictures, and the voltage tests.

Thanks


Offline Paul Birkeland

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Reply #3 on: February 19, 2025, 09:10:12 AM
The wires that leave that board and connect to the 4 pin socket aren't connected to the correct places on that filament board (they do not connect to the DC pads on the front side of the board, those should be left empty).

To the naked eye, I do not believe you have the correct resistor values in the R1 and R2 holes on this PC board.  It is extremely important to double check resistor values with your meter if you aren't 100% sure that the colors are correct, or if they are too hard to see.  I think (at minimum) that they are switched in the place where I am looking, but the 1K resistor I see has some unexpected colors, so this needs to be double checked.

If you have 1-2V coming off the front pads on that PC board, then I'd want to see what the soldering looks like on the bottom of the board, as it should be more like 8V (especially if there are no 300Bs plugged in).

Paul "PB" Birkeland

Bottlehead Grunt & The Repro Man

Offline Yossihaimberg

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Reply #4 on: Yesterday at 03:27:42 PM
Hi, I corrected the filament problems, and I think it is now as it should be. HOWEVER...  I'm measuring 120VAC at the power source (plug), but I get no output from the transformer. I checked the voltage at 7 and 8 and it is 0....  The same at 11-14 (should be 6.3V) and 12-13.

Please advise.


Offline Doc B.

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Reply #5 on: Yesterday at 03:31:42 PM
Make sure the cord is plugged in all the way at the amp and check the fuse.

Dan "Doc B." Schmalle
President For Life
Bottlehead Corp.

Offline Yossihaimberg

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Reply #6 on: Today at 08:49:45 AM
I double-checked the plug/fuse. All good.

I think that while replacing the resistors (especially the 237 ohms) I damaged the board while trying to remove the soldering. The attached pictures show the possible damage. I'm reading 6.3VDC on the left side of the board, but only 1.2 VDC on the left side.

I'll appreciate your thoughts, and if I did damage the eyelet where the 273 ohm goes, is there a way to fix it?

Thanks!!!!


Offline Yossihaimberg

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Reply #7 on: Today at 08:51:13 AM
I mean 6.3VDC on the RIGHT side, and 1.2 VDC on the LEFT side. Sorry


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