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Old 18th January 2012, 04:55 PM   #21
AndrewT is offline AndrewT  Scotland
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Join Date: Jul 2004
Location: Scottish Borders
PINs 9 & 10 are the +IN and -IN inputs.

All opamps should have almost identical voltages on these two PINs.
Something is seriously wrong.
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regards Andrew T.
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Old 29th May 2012, 02:34 PM   #22
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Join Date: Jan 2010
hi,
hamand do one thing, first of you remove lm318 from the slot,
then power on the board and ensure that you have -35 volts and +35 volts on those two big capacitors.you must keep negative terminal of multimeter on ground in the pcb(the common track for those caps is the ground) while measuring this. if you have the voltage ok there then your power section is ok.

then measure the voltage at pins 1,5,4 with respect two ground. 1 and 5 must have +35 volts and 4 must have -35 volts.

let us see the outputs
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Old 1st July 2012, 02:50 PM   #23
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Join Date: Aug 2010
Hi,
The LM3886 chip shows very low voltages at Vin+ and Vin-. Obviously something is very wrong. Would suggest you remove all the semiconductors and check the rectifier side to see if you get aprox 1.4 x Vac at the filter caps. Check to see if there are any shorts and component values placed for Resitors and Caps. If this step fails you may need to reconstruct the board. I did purchase this from Siva and it worked first time.
BTW I am impressed with your Enclosure and transformer? Where did you source these?
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