High Voltage at L3 L4

[Ipplepen]

Hi,

The C84 is my first build. I'd be very grateful for some advice regarding the following:

I have cailbrated U1 pins 8 and pin 4 +18V, -18V

However, I get around 3.4 V across L3 L4. As this should be nearer 0V it's likely I've installed a component incorrectly! So I have started to check each component in turn. The second component I checked is R28 (10K0 brown-black-black-red-brown) - however when I test with my DMM I measure 5K55; R27 (the same resistor) measure 5K55 instead of 10K0! Does this mean have have damaged these components?

Any advice?

Regards,

Mark

[Ipplepen]

Update:

Unfortunately, I foolishly rechecked after powering and C45 started to smoke.

Should I post a high res. photo of my board. Would anyone be willing to check to see what I've cocked up?

Cheers,

Mark

[Ipplepen]

Update:

Found the problem. I had mixed up Q6 and Q9. Luckliy I hadn't yet installed the opamps (now realise that my earlier question re: voltages across L3 L4 was incorrect without their insatllation).

I have built a second C84 which is working well

I suspect that some of the components in the "first" C84 have been damaged. Any suggestions how I might proceed. I need another Tantalum capacitor (C45); The reinstalled Q6 got very hot, as did u5 and u4. I can source these part in the UK.

So in summary, Q6 and Q9 were in the wrong places. C45 has blown. I put Q6 and Q9 in their appropraite places and "borrowed" a "C45" from my 2nd kit. Powerered up, but didn't go further as Q6 was initially very hot, as were U5 and U4.

Cheers,

mark