quasar v4 not working [almost solved]

[kiasyd]

Keep it up guys! If you stick with it something will turn up.

thanks, am loving this forum, you guys are great 

As for the problem in question, what are your voltage readings at the input and ground? Also, have your checked for any incorrect continuity between either the Base or the Emitter on that Q? the extra power has to be coming from somewhere, and if it's not a bad Q (which I still suspect), then it has to be a solder bridge.

i haven't read the voltage at the input, but ground is at 0v, just like it should.
can you explain a little more about testing the Q plz. i`m just relying in my backup board, my bad. i don't think it is a solder bridge, i spent like two hours just looking for one with a magnifying glass.
well guys its late here in Chile so I'm going to bed, but I'm going to be here REALY early 

thanks for all guys, I'm gonna find the way to pay you back 

[mgwhit]

it happened to me to, the datasheet shows the transistor from below, then i had to see it from abode,and the from the schematics. that isn't a good exercise after seen the same circuit all day long.
r18 is  [gold its 5% tolerance  ]

Jeez.  I'm on a roll today.     Yeah, should be Blue-Grey-Black-Brown-Brown.  I still can't tell what's going on in the multiplier band on your R18, but if you say it's Brown (x 10) I'll take your word for it.  I'm gonna play around with the voltages on your on your transistors a bit more and then I'm going to bed myself.

[kiasyd]

it happened to me to, the datasheet shows the transistor from below, then i had to see it from abode,and the from the schematics. that isn't a good exercise after seen the same circuit all day long.
r18 is  [gold its 5% tolerance  ]

Jeez.  I'm on a roll today.     Yeah, should be Blue-Grey-Black-Brown-Brown.  I still can't tell what's going on in the multiplier band on your R18, but if you say it's Brown (x 10) I'll take your word for it.  I'm gonna play around with the voltages on your on your transistors a bit more and then I'm going to bed myself.

something happened there, the message dint come as i spected. well, r18 is blue-grey-black-brown
if you want i can upload some better quality pics

[mgwhit]

No, no.  As long as you've double checked it, that's good.  For a while there I was just convinced that you must have a bad value in your power supply voltage divider, but (a.) I couldn't find one, and (b.) it actually doesn't make sense given the (high) voltages for Q1 and Q2 you posted yesterday.

VB should be around 4.5V and provides the voltage for IC1 pins 3 and 5 as well as the base of Q2, and that is almost exactly what you've got on the IC pins.  I don't think there's any explanation for having the 8.36V on the base of Q2 (or Q1 for that matter) other than bad transistors (like Jacob's been saying for a while now).  I just thought it was improbable that all four (or five, if you swapped in another one) of your transistors would be bad, but I can't come up with anything else.

I usually feel that blaming the components is bad style -- and it is much more rare that a bad component is the problem compared to builder mistakes -- but bad components do happen every now and then.  I should've paid more attention to the evidence, though.  I think you should try to get some new E-C-B transistors and see what happens.  Good luck!

[kiasyd]

No, no.  As long as you've double checked it, that's good.  For a while there I was just convinced that you must have a bad value in your power supply voltage divider, but (a.) I couldn't find one, and (b.) it actually doesn't make sense given the (high) voltages for Q1 and Q2 you posted yesterday.

VB should be around 4.5V and provides the voltage for IC1 pins 3 and 5 as well as the base of Q2, and that is almost exactly what you've got on the IC pins.  I don't think there's any explanation for having the 8.36V on the base of Q2 (or Q1 for that matter) other than bad transistors (like Jacob's been saying for a while now).  I just thought it was improbable that all four (or five, if you swapped in another one) of your transistors would be bad, but I can't come up with anything else.

I usually feel that blaming the components is bad style -- and it is much more rare that a bad component is the problem compared to builder mistakes -- but bad components do happen every now and then.  I should've paid more attention to the evidence, though.  I think you should try to get some new E-C-B transistors and see what happens.  Good luck!

thanks, I thought quite the same,but i dint have access to a great stock of transistors, but i`m gonna buy a few, to see if that works. if it doesn't the ill just quit electronics diy

[kiasyd]

It's alive!!!
just put in a socket and start swapping the transistors,  and it was doing its job.
now its a lovely booster with a lovely volume drop  i think its somethink like the revenge of the transistors , well its 4am in Chile so I'm happy fixing one problem today and leaving the other for tomorrow
thanks to you all and if you can help me with the volume drop ill be really thankfull

[mgwhit]

So did you stick with the 2sc945's or use something else this time?  And what are the voltages on your Q1 and Q2 now?  Are you getting the volume drop on both boards?