Behringer Europower PMP1000 repair mic channels

[CapLeaker]

Got this Behringer Europower PMP1000 mixer in for repair. Bugger to find a schematic for it. I managed to dig up something for a PMP3000 and that is close enough for the 1000.

Complaint: Microphone CH1 and CH4 not working. CH1 very low, CH4 no audio at all.

Fix: On this one it was on both channels a little SMD SOT-23 style NPN transistor with the marking K16. Audio goes through the PNP 1316 first and then through that offending SMD NPN. On the picture mic channel #1, board marking T10, next to D1.

Yeah, I know it isn't pretty and clean, but it's getting late and I am tired. It'll be clean and pretty tomorrow.


schematic = inside the PMP1000
PNP 1316 = 2SA940
A06 (MPSA06) = SMD marking K16 = DTC144ECAT

[CapLeaker]

Re: Behringer Europower PMP1000 repair mic channels

Hmm... I guess it was getting late the other night, but the TO-92 PNP is a 2SA970.
The SMD marked K16 is a DDTA144ECA
most other SOT23 on that mixer board are marked 1Bt and these are BC846B's.

What gets me is that these guys seriously put cheap@$$ BC transistors in there? Really really?

[Khron]

Re: Behringer Europower PMP1000 repair mic channels

Have you ever considered that the BC846's might not be in the signal path? Or do we now need "audiophile" NPN's even for turning LEDs on and off?

But on a more serious note, i'd be tempted to replace the other 2SA970 as well, on each affected channel, "just in case". I mean, if the one on one "leg" of the mic input got toasted, what're the odds of the other side of it crapping out sooner rather than later, too?

[CapLeaker]

Re: Behringer Europower PMP1000 repair mic channels

I know exactly where they are, but still... this isn't really a cheap unit to buy. One just about can't get any cheaper than BC transistors. Same sight on the PSU, everything is cheaply made. Decon caps?!?! :puke: That alone should give one a 50% rebate!

[Khron]

Re: Behringer Europower PMP1000 repair mic channels

Perhaps, but i still don't quite get what your beef is, with those BC's that are used as (low voltage, low current) switches

Totally with you on the PSU & caps there, though. Although i thought Berry were usually using Xunda caps...

[CapLeaker]

Re: Behringer Europower PMP1000 repair mic channels

So I've got these transistors and it didn't work. Well, I guess these NPN's are marked K1G, not K16. That means the replacement is a MMBTA06. I just put a MPSA06 in there and it works fine.

[Khron]

Re: Behringer Europower PMP1000 repair mic channels

Yeah, i would've been quite shocked to see so-called "digital" (ie. pre-biased) transistors in the input stages of a mic preamp.

https://cdn.badcaps-static.com/pdfs/...7310ac7974.pdf

Even the schematics showed the NPN's as "A06" => MMBTA06.

[CapLeaker]

Re: Behringer Europower PMP1000 repair mic channels

well, I thought I read a marking of K16 on the transistor with the magnifying glass. Turned out it was K1G well... well well. I jammed a MPSA06 in there and all is good.