Hello forum, please help

[Hanitpal]

This is the C84 model Rev 2.0 (latest rev).
Here's a link to the picture i took (its the best I can do atm):

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Hi geekslutz forum. I have been having a strange problem with an SCA preamp that i have been trying to build for a while now. My brother tried helping, but he was no help, but he did send me to this forum for help.

My MAT14ARZ at Q2 is frying and i dont know what to do about it. First, my Q1 and Q2 both fried, so I had to take them off and order 2 new ones. This second time only Q2 sparked. I put them on and flipped the power switch and noticed a tiny blue spark on Q2 and IMMEDIATELY shut it off.

I have 2 questions:
1. What is my problem?
2. Since it was only a little blue spark, does that mean my MAT14ARZ at Q2 is still good, or will I have to replace this expensive sucker again?

Im thinking it may have been a short circuit due to excessive liquid flux left over

Thanks in advance,
Hanitpal

[Hanitpal]

http://i.imgur.com/erlCp.jpg

It didn't allow me to post links until I had at least one post

[tpryan]

Not to be discouraging, but if that's the best soldering you can do you should have had us build it for you. I recommend you just send it in for a rebuild. Send an e-mail to rma@seventhcircleaudio.com for return instructions.

[Hanitpal]

Not to be discouraging, but if that's the best soldering you can do you should have had us build it for you. I recommend you just send it in for a rebuild. Send an e-mail to rma@seventhcircleaudio.com for return instructions.

Thanks for the response Tim.
To be honest with you, the entire board is soldered very well, including the other mat14. this is probably the only component soldered poorly. But I do admit that it was soldered VERY poorly

Not to mention the little bits of money I've spent buying and re-buying some of the components and the liquid flux.

If I were to send this thing in for a full rebuild, not only would I be losing a chance to save a lot of money, I would be throwing away an entire board for one poorly soldered surface mount whose pads are not even lifted


Here's what I'll do, and tell me if you concur. Ill add enough solder so that I can cleanly remove the mat14 that I'm having issues with, and I'll quickly and safely wick everything when I'm done. Then I will re-solder that thing and swap the (possibly) fried ceramic cap at position c44 for a new one. Then we will see whether I need to turn it in to you or not.

Thanks,
Hanitpal