Behringer BX4500H

[g1]

Thank you G1. Putting all those together, we now have a complete set. I don't know the etiquette, but maybe we should put them together and make a single post? I'm happy to do that.

Post #2 now edited to include both schematics.

[tbonuss]

Thank you VintageKiKi. Very helpful.
Thank you Enzo--gotit. I wasn't sure about the illustrated voltages. I appreciate the tip.
Thank you JMFahey, I appreciate the insight.
Thank you G1. Putting all those together, we now have a complete set. I don't know the etiquette, but maybe we should put them together and make a single post? I'm happy to do that.

Again, thank you.
Steve

[J M Fahey]

So, the PCB for the power amp and p/s says: Behringer Model P3000.

You should have mentioned it on the first post

I had found upto LPA1300, its smaller sister, 4 power transistors instead of 6 but everything else exact same values.

All Designers have their pet ideas which they repeat over and over, so very often a certain model schematic is close enough to help servicing others.

[Enzo]

P3000 is a few years older. They are VERY similar, down to the part numbers even. But they differ. As far as I can spot, mainly in the compressor. The P3000 uses the older 3080IC in IC5, while the LPA1450 uses a 13700 IC, I would say the boards are equivalent, and they just went to the newer style board at some point during production.

But since yours is blowing fuses, I highly doubt the compressor is involved, and the power amp part ought to be the same.

The red voltages on the drawing kiki posted look to me like they are from someone's problem amp, so don't use them as models.

[vintagekiki]

https://www.diyaudio.com/forums/instruments-and-amps/267828-behringer-bx3000t-bass-head.html

https://www.diyaudio.com/forums/attachments/instruments-and-amps/597547d1486447983-behringer-bx3000t-bass-head-p3000reve-pdf
_{P3000REVE.pdf}

1)
https://www.talkbass.com/threads/behringer-bx4500h-power-rail-voltage-differences.1442171/
_{Behringer BX4500H Power rail voltage differences}

https://www.talkbass.com/attachments/p3000reve-pdf.3660804/
_P3000REVE

[tbonuss]

LPA1450 is the power amp. I am not sure what else it might be in.

Sorry Enzo. Posting at the same time. Is that the same thing as P3000?

[tbonuss]

Yes. Thank you. The pre-amp seems to be fine, and the power amp is blowin' fuses. So, the PCB for the power amp and p/s says: Behringer Model P3000. I will look for that then. Again, thank you.
Steve

[Enzo]

LPA1450 is the power amp. I am not sure what else it might be in.

[g1]

edit:
Preamp and power amp schems. attached.

[tbonuss]

I've not been able to find anything beyond dead links for this (including here on MEF). If I've missed it, please know that it's not due to a lack of effort.
Thanks in advance.
Steve