01-20-2014, 03:23 PM
Tim
1. I apologize, I meant between the R2 and the "Negative of C1" (where R3, R4, C1 negative and the transformer come together). Can you repeat it? If it still is broken on the low volume:
Can you do the following:
With the whole thing turned on (when you connect the musical source or when you play a record), can you measure the voltage between:
1. the Ground and the "-3V" battery terminal?
2. the Ground and the lower (according to the schematic) L5022 transistor's Collector terminal (the one going to -3V)? Measure right at the terminal.
3. the Ground and upper transistor's Emitter?
4. the ground and "+3V" battery terminal?
When measuring voltage on batteries' terminal, measure at actual spring contacts or better yet and NOT on the batteries own contacts. Better yet measure at the point where wires solder to those contacts.
What I want to know is what voltage the actual schematic is seeing. The contacts may be dirty or oxidized and I want to exclude it.
Additional:
With unit OFF:
1. try to measure with Ohmmeter across both transformers' primary and secondary windings.
When measuring wait for a few seconds making the result is stable (there is a capacitor there).
list the readings here.
For the first transformer they are 3700/120 Ohms for primary/secondary.
For the secondary they are 150 for primary and 14.5 for both secondaries.
2. Measure resistors R2 through R10. List the values.
1. I apologize, I meant between the R2 and the "Negative of C1" (where R3, R4, C1 negative and the transformer come together). Can you repeat it? If it still is broken on the low volume:
Can you do the following:
With the whole thing turned on (when you connect the musical source or when you play a record), can you measure the voltage between:
1. the Ground and the "-3V" battery terminal?
2. the Ground and the lower (according to the schematic) L5022 transistor's Collector terminal (the one going to -3V)? Measure right at the terminal.
3. the Ground and upper transistor's Emitter?
4. the ground and "+3V" battery terminal?
When measuring voltage on batteries' terminal, measure at actual spring contacts or better yet and NOT on the batteries own contacts. Better yet measure at the point where wires solder to those contacts.
What I want to know is what voltage the actual schematic is seeing. The contacts may be dirty or oxidized and I want to exclude it.
Additional:
With unit OFF:
1. try to measure with Ohmmeter across both transformers' primary and secondary windings.
When measuring wait for a few seconds making the result is stable (there is a capacitor there).
list the readings here.
For the first transformer they are 3700/120 Ohms for primary/secondary.
For the secondary they are 150 for primary and 14.5 for both secondaries.
2. Measure resistors R2 through R10. List the values.