Voxx,
I remembered your comment on not liking to desolder. It's not my favorite either, especially on parts with more than 2 legs. You probably know all this, but I thought I would share for others in this new build, just in case. If you are going to replace transistors or other through hole parts with multiple legs, it is often easiest just to cut the legs, then remove the legs left behind, one by one.
I will mention that Dario has recommended an unsoldering kit that is a lifeline. It contains solder wick which soaks the solder out of the hole so that you can put the new part into the hole. It also has a low temp solder that will let you unsolder surface mount parts like the LM317. Finally, it has tacky flux that helps you hold surface mount parts when soldering.
I didn't know about this stuff before and what a relief to learn about it. Now I'm popping parts off at the drop of a hat just to test them, cleaning up with solder wick, and soldering again.
Jac
I remembered your comment on not liking to desolder. It's not my favorite either, especially on parts with more than 2 legs. You probably know all this, but I thought I would share for others in this new build, just in case. If you are going to replace transistors or other through hole parts with multiple legs, it is often easiest just to cut the legs, then remove the legs left behind, one by one.
I will mention that Dario has recommended an unsoldering kit that is a lifeline. It contains solder wick which soaks the solder out of the hole so that you can put the new part into the hole. It also has a low temp solder that will let you unsolder surface mount parts like the LM317. Finally, it has tacky flux that helps you hold surface mount parts when soldering.
I didn't know about this stuff before and what a relief to learn about it. Now I'm popping parts off at the drop of a hat just to test them, cleaning up with solder wick, and soldering again.
Jac
This assembly is similar to carpentry, measure twice and then cut once and in this instance read the directions five times so you hopefully wont have to desolder.
I happened to swap the 1000nf cap with the 100nf and can agree that the wick works wonders for opening the hole for insertion. Also a pick and a 3rd hand are useful for deconstruction.
I happened to swap the 1000nf cap with the 100nf and can agree that the wick works wonders for opening the hole for insertion. Also a pick and a 3rd hand are useful for deconstruction.
If you already have the through hole component off the board don't bother with the wick and endless amounts of heat to try and coax the solder out of the via's. Use a toothpick! Heat the solder and insert the toothpick into the via, remove heat, wait a second or two remove tooth pick. The solder wont cling to the tooth pick and now you have an unobstructed via. This has saved me hours of time and an unknown amount of frustration.
And for smd components the chipquik alloy is the king.
And for smd components the chipquik alloy is the king.
Bob, both ,modules behaved identically till yesterday. Everything was fine (only reversed q1 which I fixed).
Only odd value was 22 v instead of 35 , and while measuring it I could short poles with multimeter. Now on that board relay is clicking and dc offset shows presence on 4 v on output.
I know I should be more careful with everything and it is not making your help any easier .
I did not connect boards yet because I was not sure how 22 v value was bad to the assembly.
Only odd value was 22 v instead of 35 , and while measuring it I could short poles with multimeter. Now on that board relay is clicking and dc offset shows presence on 4 v on output.
I know I should be more careful with everything and it is not making your help any easier .
I did not connect boards yet because I was not sure how 22 v value was bad to the assembly.
Don't be concerned about that. Every post is potentially helpful to other builders. Do you have any inexpensive speakers that can be sacrificed if necessary?
Emmm... can source something, and I was going to do so. It will take some time.
At least I can check if one channel is working or not.
Regarding short on another board-
Dario mentioned if dc offset is high I need to replace lm318.
Plus one of lm317 is getting extremely hot, I ll swap it for another one.
Do I need to check anything else to make sure other components are fine ?
At least I can check if one channel is working or not.
Regarding short on another board-
Dario mentioned if dc offset is high I need to replace lm318.
Plus one of lm317 is getting extremely hot, I ll swap it for another one.
Do I need to check anything else to make sure other components are fine ?
Hi Ivan,
if dc offset is optimal you can safely connect speakers.
So, correct me if I'm wrong:
- Initially both boards measured 22V on LM317s input and one had a reversed Q1
- You replaced Q1, still 22V
- After shorting one of the LM317s that boards started to measure 35V but you have seriuos DC on output.
Ok. I powered board to check for sure if smoothing caps are 35. And they are
I checked all values.
Parts from *100 side measured: 1.26 (1.25) 22.7 (35) 14.1 (14.6)
Parts from shorted *200 side: 0.327 (1.25) 33 (35) 3.6 (14.6)
In a mean relay stabilised and stopped clicking.
I checked dc offset and what a wonder - it bounced from 35 mV to 2mV. So I waited a bit to cool it down and powered it again - dc was 3 or 4 V and got down and down with every click of relay.
I checked all values.
Parts from *100 side measured: 1.26 (1.25) 22.7 (35) 14.1 (14.6)
Parts from shorted *200 side: 0.327 (1.25) 33 (35) 3.6 (14.6)
In a mean relay stabilised and stopped clicking.
I checked dc offset and what a wonder - it bounced from 35 mV to 2mV. So I waited a bit to cool it down and powered it again - dc was 3 or 4 V and got down and down with every click of relay.
