Behringer B215a blown help needed.

[basher106]

Hi all just after a little help, i've been given a blown up Behringer B215a powered monitor for free! so decided to try and resurrect it so far i have found and replaced the following damaged parts

IC1 - tda7293v had blown to bits!!
C1 - 22uf/100 had blown cap off the board been replaced
C40 a big 6800uf 50v had really high esr reading and weird value out of circuit tested so replaced with new one
T1 and T2 sap16n and sap16p were shorted and replaced
Ic2 7815 and ic3 7915 where giving real low 10v and 11v out replaced
D3 and D40 KBL04 rectifiers where both shorted and replaced
T3 IRFP9140n T4 irfp140n where both shorted and replaced
R16 and i think i also replaced R17 but forget to make a note of it, both white ceramic resistors blown

Hands up i admit my electronics skills are limited and i can't seem to test a few of the tiny sot23 mosfets On the
schematic T5 and T7 it says 139 for both (just above bottom left above where it says revisions)
im hoping its a bss139 and the data sheet says pins 123 left to right are G D S
so i put - lead onto source and positive to drain i keep getting beep or short on multimeter i try touching all pins to turn it off if thats how it works
im fine with other mosfets and theres very little anything on youtube on sot23 reading them i did test them on a 328 tester
and it says the mosfet doesnt say good or bad but its the d s pin reading short that im concerned about i ordered two brand new
bss139 sot23's today and they appear to be shorted as well so i'm pretty sure i'm testing them wrong.

Also T16 marked j113 seems to test as shorted at D S out of circuit so i dont really want to refit or replace till i know its good.

Ive also attached the schematic the amp power section is definately correct but the smaller input volume board on schematic is not i think it says revb for input board
my input board is revd and when i went to have a quick look the resistor values or different if any one has schematic for behringer eurolive b215ain pcb/71601REVD that would be fantastic ive spent hours look thrugh all the beringer links and can't one great forum by the way.

[basher106]

Hi all just after a little help, i've been given a blown up Behringer B215a powered monitor for free! so decided to try and resurrect it so far i have found and replaced the following damaged parts

IC1 - tda7293v had blown to bits!!
C1 - 22uf/100 had blown cap off the board been replaced
C40 a big 6800uf 50v had really high esr reading and weird value out of circuit tested so replaced with new one
T1 and T2 sap16n and sap16p were shorted and replaced
Ic2 7815 and ic3 7915 where giving real low 10v and 11v out replaced
D3 and D40 KBL04 rectifiers where both shorted and replaced
T3 IRFP9140n T4 irfp140n where both shorted and replaced
R16 and i think i also replaced R17 but forget to make a note of it, both white ceramic resistors blown

Hands up i admit my electronics skills are limited and i can't seem to test a few of the tiny sot23 mosfets On the
schematic T5 and T7 it says 139 for both (just above bottom left above where it says revisions)
im hoping its a bss139 and the data sheet says pins 123 left to right are G D S
so i put - lead onto source and positive to drain i keep getting beep or short on multimeter i try touching all pins to turn it off if thats how it works
im fine with other mosfets and theres very little anything on youtube on sot23 reading them i did test them on a 328 tester
and it says the mosfet doesnt say good or bad but its the d s pin reading short that im concerned about i ordered two brand new
bss139 sot23's today and they appear to be shorted as well so i'm pretty sure i'm testing them wrong.

Also T16 marked j113 seems to test as shorted at D S out of circuit so i dont really want to refit or replace till i know its good.

Ive also attached the schematic the amp power section is definately correct but the smaller input volume board on schematic is not i think it says revb for input board
my input board is revd and when i went to have a quick look the resistor values or different if any one has schematic for behringer eurolive b215ain pcb/71601REVD that would be fantastic ive spent hours look through all the behringer links and can't find one great forum by the way.

****Just an update I seem to have fixed my amp! I plugged in a current limiter bulb and it showed no or little current draw a bright light only for split second on power up boxed it all back up powered on and it worked, I ran it for a couple of hours with a mp3 play patched into an xlr with a lead i made at loud volume and it seems fine eq section sounds ok bass mid treble will see how it goes still uncertain about the bss139
And j113 doh 23 mosfet they tested shorted but all seems well !.****

[Enzo]

A J113 is a JFET. A JFET NORMALLY has a low resistance D-S until it is turned off by a gate voltage. SO out of circuit, it is normal to measure "shorted". But typically that "shorted" is more like 200 ohms. WHen we bias the transistor with a gate voltage it turns off and resistance rises.

[nosaj]

****Just an update I seem to have fixed my amp! I plugged in a current limiter bulb and it showed no or little current draw a bright light only for split second on power up boxed it all back up powered on and it worked, I ran it for a couple of hours with a mp3 play patched into an xlr with a lead i made at loud volume and it seems fine eq section sounds ok bass mid treble will see how it goes still uncertain about the bss139
And j113 doh 23 mosfet they tested shorted but all seems well !.****

Your not still running it with a current limiter are you?

nosaj

[basher106]

No, i used current lamp for first power up when I reassembled it.. I did forget at one point when I noticed the powered monitor / amp was now working and i upped the volume it cut out! i thought well that's for the bin! but thought it could be either the current limiter or amp tripping the amp out, which it had, I eventually plugged straight into mains and powered back up and drove the amp for a couple hours with some loud music and it seems fine for now! I'm actually quite chuffed with the repair, as for the jfet I soldered 3 wires onto it and connected it to my 328 tester and it recognized it correctly so I just took it as working although still wasnt sure and thought and would just blow newly fitted amp parts again but it seems fine for now.

[basher106]

Ok thanks for reply and info so how would you recommend I test a j113 I remember I removed it (and the bss139) from pcb they appeared shorted whereas the rest tested ok in circuit I don't mind removing the ones that appear shorted and putting them on my m328 LCD tester that seemed to recognise the j113 ok or is there an easier way? Also I forget to mention i ordered new j113 and bb139 and they appeared to be shorted so I knew them it was me who was faulty ! oh they joys of electronics!..