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June 27, 2022, 04:16:11 PM

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#91
Amplifier Discussion / Re: Fender 112 Deluxe Plus
Last post by g1 - May 28, 2022, 03:26:02 PM
That's good.  Now measure DC voltage at CR39 anode and cathode.
#92
Amplifier Discussion / Re: Fender 112 Deluxe Plus
Last post by FenderDeluxe112Plus - May 28, 2022, 03:12:45 PM
Apologies .0002 ohms for both readings.
#93
Amplifier Discussion / Re: Fender 112 Deluxe Plus
Last post by g1 - May 28, 2022, 03:00:55 PM
Quote from: FenderDeluxe112Plus on May 28, 2022, 02:07:53 PMContinuity between cr39 anode and Q1 base.
Continuity between Q8 collector and cr39 cathode.
Please specify reading in ohms.  Continuity is a somewhat vague term that changes depending on model of meter.  If relying on a meter beep for continuity, it can range anywhere from zero to 200 ohms.
#94
Amplifier Discussion / Re: Fender 112 Deluxe Plus
Last post by FenderDeluxe112Plus - May 28, 2022, 02:13:49 PM
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Test point pairs marked in red and green.
#95
Amplifier Discussion / Re: Fender 112 Deluxe Plus
Last post by FenderDeluxe112Plus - May 28, 2022, 02:07:53 PM
Continuity between cr39 anode and Q1 base.
Continuity between Q8 collector and cr39 cathode.
#96
Amplifier Discussion / Re: Fender 112 Deluxe Plus
Last post by g1 - May 28, 2022, 01:47:46 PM
According to the schematic, that is impossible.
So something funny, or we don't have a schematic match.

Check resistance from CR39 anode to Q1 base.  And resistance from CR39 cathode to Q8 collector.
Same for CR40 to Q2 and Q9.

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#97
Amplifier Discussion / Re: Fender 112 Deluxe Plus
Last post by FenderDeluxe112Plus - May 28, 2022, 04:13:57 AM
Thanks g1. Have just double checked the dc voltages.

Q1 base 01.23 vdc
Q8 collector 03.29 vdc

Q2 base -01.20 vdc
Q9 collector -02.74 vdc


#98
Amplifier Discussion / Re: Fender 112 Deluxe Plus
Last post by g1 - May 27, 2022, 11:17:58 PM
Double check those collector voltages for Q8 and Q9.
Where could they be getting a voltage higher than the base voltages of the outputs?
(ex. Q1 base is 1.2V, Q8 collector gets voltage from that line)
#99
Amplifier Discussion / Re: Fender 112 Deluxe Plus
Last post by FenderDeluxe112Plus - May 27, 2022, 04:23:09 PM

Q8
E-00.03
B-00.09
C 02.92

Q9
E-00.04
B 00.02
C-02.59
#100
Amplifier Discussion / Re: Fender 112 Deluxe Plus
Last post by FenderDeluxe112Plus - May 27, 2022, 04:07:35 PM
Q1
B01.22
C39.22
E-00.02

Q10
B01.22
C39.20
E-00.02

Q11
B-01.19
C-39.47
E-00.05

Q2
B-01.19
C-39.44
E-00.05

All without speaker load