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Old 02-14-2018, 03:44 PM   #35
R_J
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Join Date: Jun 2012
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Posts: 3,286
Default Re: Philips FR-740 working but no audio output

I wonder if 7309 is'nt bad, there should be -34.5 volts on the collector. I guess you could check the 2 100k's 3329 & 3936
-------from other post-------
ok, page 79:
A of 6305: 0V
K of 6305: 3.2V
C of 7309: 0.04V <------------the schematic indicates there should be -34.5 volts here
C of 7304: -41.5V
C of 7310: -41.5V
--------------------
I see from before
STK496-270
11 = 39,5V
14 = -33,5V
10 = -39,5V
3,4,19 = -40V
7,8,9,12,13,15,16,17,18,20 = 0V <------------pin 12 listed as 0 volts
7309: E= 3.4V, B= 3.05V, C= -1.4V
7304: E= -40.3V, B= -39.6V, C= -40.3V
7902: E= -40.3V, B= -39.6V, C= -40.3V <-------7902 (C) listed as -32V
check the voltage on resistor 3918 and then 3935

I checked a data sheet for a STK486-430 and the CCC pin only changes BY 2 volts between amp on and amp off (it uses -50v amp ON -52v amp OFF)

Last edited by R_J; 02-14-2018 at 04:22 PM..
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