C84 Rev. 1.4 Problems - R48 Smoking/Blown....

[ryansteele]

I have 2 channels, Rev. 1.4. Upon initial powerup for voltage adjustment, r48 smoked on both, and actually blew out on one. Also, the LED next to q8 was lit. Before it blew (R48 that is), I got a reading of +/- 14.4V an U1.

I have double checked the caps and transistors to make sure everything is correct, and looked for solder bridges....found nothing.

Again, I have 2 channels, built at the same time, with the same problem....obviously, I made the same mistake on both.

Anyone have an idea what the mistake actually is? Or at least a place to start troubleshooting?

Thanks in advance.

[tpryan]

Can you post a clear, well-lit photo of the area around Q8/Q9?

[ryansteele]

http://picasaweb.google.com/ryandenmarksteele/C84

let me know if you need me to mail you the higher res ones somehow...google seems to limit the resolution.

anyways, in case you can't tell,

Q5/Q12 - bc560
Q6/Q13 - bc550
Q8/Q15 - mje18
Q9/Q16 - mje172

any ideas?

thanks.

[ryansteele]

Need help.....anyone?

[tpryan]

Mysterious. I think you'll have to send it in.