Update! now I got input Mic-1 and Mic-2 and the line in working, but not the main one 1 high 1low! I'm a guy who like this kind of challenge, I haven't got any back ground study on electronic, I see that a part from you nobody make an afford to help me! I will keep try with the hope that someone joint to help...

 

What is main 1 high 1 low?

 

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What is main 1 high 1 low?

Hi, thank you for reply, I meant the input for guitar, almost all amp got 2 entry 1 high and the other is the low one, I assume the low is for guitar with amp! they are the main channel the other 3 are extra. Yes you are right, but when I brought it I was sure that the seller was ok! Do you think is a fake Chinese one? Anyway now I put a different one which come from Bose amp, do you think that the problem is still the TDA? Are they all the same? I mean any variant of it? I been searching for this information and I come to the conclusion that they are all the same, is it correct?

 

Firstly, this is mains powered equipment - don't do anything unless you are competent to avoid electric shocks - take it to an experienced repair shop instead. If you go ahead I suggest you go to the junction of R43 and C31 (positive side of supply) and R43 and C30 (negative) these are the power supply outputs. Quite probably there are wires that take the positive and negative lines from these junctions. Temporarily de-solder these wires to isolate the supplies from their respective loads. Clip the negative lead of your multimeter to the chassis then measure the DC voltages at those two junctions. Are you getting + 12Vdc at one junction and -12Vdc at the other?

 

I noticed that the noise when worn up are gone just litl

Firstly, this is mains powered equipment - don't do anything unless you are competent to avoid electric shocks - take it to an experienced repair shop instead. If you go ahead I suggest you go to the junction of R43 and C31 (positive side of supply) and R43 and C30 (negative) these are the power supply outputs. Quite probably there are wires that take the positive and negative lines from these junctions. Temporarily de-solder these wires to isolate the supplies from their respective loads. Clip the negative lead of your multimeter to the chassis then measure the DC voltages at those two junctions. Are you getting + 12Vdc at one junction and -12Vdc at the other?

Thank you for reply! Do you mean R43 and R44? Or as you said? I misure only R43 and R44 that's only because the C30 and c31 have the contact under the board and to get to it need time to disassembly, I'm out, (I have just assembled the thing) but what I get is on R43 are 12,3v on the other side -44,2v (R44) which I assume is not right. Please tell me if you need also c30-c31 measurement, I will do when back in the evening! but if it should be 12vdc on both mean that the problem is there, how can I solve it, can't find any faulty resistor... I have spend hours try to solve many problem on this thing! Now at least something is working, so I'm please to know that I'm not completely stupid!! And a deserve your help! ;-)

 

do you think that the problem is still the TDA? Are they all the same?

All genuine TDA chips should be the same. From my perspective it appears you have an intermittent problem with the mixer portion of the amp. The TDA chip should not have anything to do with this. The Jam 150 is a bi-amp with the TDA amplifying the highs through the small speaker and a separate amp for the bass shown in the second page of the schematic listed in post #2.
You haven't mentioned how you got the two mic inputs to work.

 

All genuine TDA chips should be the same. From my perspective it appears you have an intermittent problem with the mixer portion of the amp. The TDA chip should not have anything to do with this. The Jam 150 is a bi-amp with the TDA amplifying the highs through the small speaker and a separate amp for the bass shown in the second page of the schematic listed in post #2.
You haven't mentioned how you got the two mic inputs to work.

the input start working after change C3 C4 and R1 R2 which blow after change the TDA, It happen in front my aye, I saw them burning! And I cannot understand why this happen, I power it up and it has been working for 10 min, the noise were gone! it was working fine than it blow, the 3 times I see spark coming from the right side of TDA first 2 legs. I change those component for 3 times, until I decided to replace again the TDA with this thats come from BOSE amp, with this, it has stoped blowing the C3 C4 R1 R2. You are telling me that it has nothing to do, so i'm more confuse now than before, should be possible to blow C3 C4 R1 R2 with a fake chip installed? The mixer was fine before it happen, all channel was working perfectly! Also it has never been touch! I wrote to Schertler, but no reply from them (last time they answer very quickly) so I don't know where to find the mixer schematic! Another guy suggest me to misere R43 and R44, which i did it he said that I should get 12vdc on both side, but I found out that the R44 has 44.2vdc in stead of 12vcd! I think this is one of the problems, but the guy did not reply yet..What do you think?

 

There are two identical regulator circuits - the one with transistor Q9 produces a positive (relative to ground) voltage rail and the one with transistor Q10 produces a negative voltage rail (relative to ground). Between these two rails is a total of 24 Volts. The fuse F2 supplies -45 volts to Q10 but Q10 is not regulating the voltage and bringing it down to the required -12V as it should. Now I would compare the two circuits side by side. for example check R41 against R42, R2 against R1 and so on. I would not reconnect the faulty negative rail to the rest of the circuit until you have repaired it and it is producing -12V. -45V is much higher than the rest of the circuit is designed to receive and might cause further damage, Do you know how to test a transistor with a multimeter? It is easy and I'm sure there are videos on YouTube explaining how to do it better than I can here. Also, remember that you cannot really check components when they are wired into a circuit because you are also measuring other components. For example if you check R44 in circuit you are also measuring across C31. In other words you often need to take components out of the board at one end so you can measure it independent of other components.
Good luck!

 

so I don't know where to find the mixer schematic!

 

I should get 12vdc on both side, but I found out that the R44 has 44.2vdc in stead of 12vcd

That's a problem! Suspect Q10 and associated components.

 

There are two identical regulator circuits - the one with transistor Q9 produces a positive (relative to ground) voltage rail and the one with transistor Q10 produces a negative voltage rail (relative to ground). Between these two rails is a total of 24 Volts. The fuse F2 supplies -45 volts to Q10 but Q10 is not regulating the voltage and bringing it down to the required -12V as it should. Now I would compare the two circuits side by side. for example check R41 against R42, R2 against R1 and so on. I would not reconnect the faulty negative rail to the rest of the circuit until you have repaired it and it is producing -12V. -45V is much higher than the rest of the circuit is designed to receive and might cause further damage, Do you know how to test a transistor with a multimeter? It is easy and I'm sure there are videos on YouTube explaining how to do it better than I can here. Also, remember that you cannot really check components when they are wired into a circuit because you are also measuring other components. For example if you check R44 in circuit you are also measuring across C31. In other words you often need to take components out of the board at one end so you can measure it independent of other components.
Good luck!

There are two identical regulator circuits - the one with transistor Q9 produces a positive (relative to ground) voltage rail and the one with transistor Q10 produces a negative voltage rail (relative to ground). Between these two rails is a total of 24 Volts. The fuse F2 supplies -45 volts to Q10 but Q10 is not regulating the voltage and bringing it down to the required -12V as it should. Now I would compare the two circuits side by side. for example check R41 against R42, R2 against R1 and so on. I would not reconnect the faulty negative rail to the rest of the circuit until you have repaired it and it is producing -12V. -45V is much higher than the rest of the circuit is designed to receive and might cause further damage, Do you know how to test a transistor with a multimeter? It is easy and I'm sure there are videos on YouTube explaining how to do it better than I can here. Also, remember that you cannot really check components when they are wired into a circuit because you are also measuring other components. For example if you check R44 in circuit you are also measuring across C31. In other words you often need to take components out of the board at one end so you can measure it independent of other components.
Good luck!

Hi, Thank you so much for the advice, and sorry for late reply! Yes I tested and compare a lot of component since I start my nightmare! But I cannot find anything wrong! I measured the Q10 and all 3 legs produce 44vdc but when I check outside the board it was ok, I change it with one from the same board where I get the TDA (Bose Board) and when I switched it on I get cracking noise! I turn it off straight away and I replace it with the old one..You said to isolate the rail but honestly I don't understand what do you mean by it? Do you think could be the Q10 faulty? And the one I replace as well? I don't know what to think! I'm lost in idee, I keep looking at this board and wandering what I missing! but I can't find it! What would be the first thing you will check?

 

Thank you very much bro! Where did you find it?

 

That's a problem! Suspect Q10 and associated components.

Yes I do agree that it what i'm suspecting too, but I can't find anything wrong! From where do you start if you were in my place?

 

Take voltage readings on Q10.
With the negative lead on ground you should read appx -45 volts on the collector, -13 volts on the base and -12 volts on the emitter.

 

Take voltage readings on Q10.
With the negative lead on ground you should read appx -45 volts on the collector, -13 volts on the base and -12 volts on the emitter.

I found what was the cause of the high voltage! Was a diode D3. Now the noise are gone and I have 12vdc has was suppose to be. The problem is still with the input 1 and 2 high low! Now I start to think that the high voltage have damage the mixer where the input are! I very kind person in the forum jakze found me the mixer shematic, if you could help would be great, Thank you

 

Only inputs 1 and 2, I would have guessed the entire mixer would have gone down.
Those 4560 chips are rated at + and - 18 volts max.
I would start with voltage readings on U1 and U12.
I have to leave shortly but can resume this conversation in a few hours.

 

Thank you very much bro! Where did you find it?

I got it from producer a few day ago. I have a similar problem as you. I got three files

 

I got it from producer a few day ago. I have a similar problem as you. I got three files

Thank you so much bro!! I ask for it but they said that they didn't send the full schematic but just part of it! On my last email they don't even reply to me..Anyway did you sort out your problem? I manage to get the power down as should (with help of nice people here) but now I have the main connection that doesn't work all the rest work but the high and low doesn't, I assume that the eccessive voltage overload the mixer and something blow, but I'm not sure, I'm guesting, it was working before..I don't know about amp I fixing thing like an hobby (at least i'm try) Any suggestion?

 

I don't know about amp I fixing thing like an hobby

I bought this amp broken for fun, i am completely beginner, i can not help you. regards