Looks fine to me - I am very pleased for you!
Sansui BA-3000 t/former testing & DBT fail
- Thread starter BradWil
- Start date
Sanken Rectifiers
D01 SG-5TS common cathode
D1 Vf=0.572V If=4.401mA
D2 Vf=0.573V If=4.401mA
D02 SG-5TR common anode
D1 Vf=0.578V If=4.393mA
D2 Vf=0.555V If=4.416mA
Tested with Atlas DCA55
Mica seems intact
D03 C08PN (1850) common cathode
D1 Vf=0.615V If=4.358mA
D2 Vf=0.619V If=4.3545mA
D04 C08PR (1850R) common anode
D1 Vf=0.613V If=4.359mA
D2 Vf=0.607V If=4.366mA
F-2511 top and bottom photos
Transistors next
D01 SG-5TS common cathode
D1 Vf=0.572V If=4.401mA
D2 Vf=0.573V If=4.401mA
D02 SG-5TR common anode
D1 Vf=0.578V If=4.393mA
D2 Vf=0.555V If=4.416mA
Tested with Atlas DCA55
Mica seems intact
D03 C08PN (1850) common cathode
D1 Vf=0.615V If=4.358mA
D2 Vf=0.619V If=4.3545mA
D04 C08PR (1850R) common anode
D1 Vf=0.613V If=4.359mA
D2 Vf=0.607V If=4.366mA
F-2511 top and bottom photos
Transistors next
Attachments
They look OK - perhaps surprisingly - leaving only the remote possibility of 'breakdown under load'.
Next step I recommend: - connecting the secondary to the low current supply, (Yellow-Green-Yellow) and measuring voltage +ve & -ve to ground, applying power with DBT & Variac if wanted. For this test it shouldn't matter that the output of the rectifiers can 'see' the regulator circuitry. Should get a small flash from the DBT and dimming to almost nothing.
You could continue selectively reconnecting stuff one at a time, in the above fashion - 'baby steps'
Next step I recommend: - connecting the secondary to the low current supply, (Yellow-Green-Yellow) and measuring voltage +ve & -ve to ground, applying power with DBT & Variac if wanted. For this test it shouldn't matter that the output of the rectifiers can 'see' the regulator circuitry. Should get a small flash from the DBT and dimming to almost nothing.
You could continue selectively reconnecting stuff one at a time, in the above fashion - 'baby steps'
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I just realised that even though the driver amps are isolated, pins 18, 24, 25 on F-2511 and the blue/red leads to the filter caps are connected to the output array. The outputs are all original matched Sanken and tested fine during restoration. Any outputs shorting to ground would also cause a DBT fail, even with the driver amps isolated, right?
I will remove the heatsinks and test each one next ...
I will remove the heatsinks and test each one next ...
Yes, I think so, if the short were C-E, but probably not if B-E for example.