I need help with debugging an Aquaboy DLX 2019

[Ariosto]

Which problems are common in such cases? The diode perhaps? How can I follow the elctric signal? Tester or audio probe?

[Ariosto]

Then the board isn't getting power, that's why the LED won't light.
Figure out why power isn't getting through to the regulator

Which problems are common in such cases? The diode perhaps? How can I follow the elctric signal? Tester or audio probe?

[Ariosto]

I´m back. I checked the 9v input from thesocket until Q4 and it was everything OK, then I went to the D1 and D2 and there is no more voltage. Do you think I must replace them?

[danfrank]

You mean you're getting voltage on Q5? Q5 is the BS250 transistor, it should be passing voltage. If you're not getting voltage on pin 8 of the LT1054, then your BS250 is probably not working

[Ariosto]

You mean you're getting voltage on Q4? Q4 is the BS250 transistor, it should be passing voltage. If you're not getting voltage on pin 8 of the LT1054, then your BS250 is probably not working

Sorry, my mistake. I mean, Q5 and not Q4. Noob question again, must I have voltage in D1 and D2 as well? Because I don´t have any.

[danfrank]

See above

[Ariosto]

See above

Well, I checked the voltages in Q4 and pin8 of IC 7. Both are 9.12 volt.

[danfrank]

Well that's good!
What I would do is pull out IC7 and then check the diodes with your multimeter.
Even with IC7 out of circuit, you should get around 8 volts around pin 1 of the regulator

[Ariosto]

Well that's good!
What I would do is pull out IC7 and then check the diodes with your multimeter.
Even with IC7 out of circuit, you should get around 8 volts around pin 1 of the regulator

Well, I pulled off the IC7 as you recommended and the diodes measures 9.15V more or less. But something suspicious happen when I check the voltage in the regulator, because I become again 9 volt IN ALL THREE PINS...... Is that normal?

[danfrank]

The center pin of the regulator should be ground... 0 volts. You either have a solder bridge or that regulator is bad

[Ariosto]

The center pin of the regulator should be ground... 0 volts. You either have a solder bridge or that regulator is bad

I ´ve already checked and there is any solder bridge. I can only guess that the regulator is bad like you said. I hate desoldering because the risk of damaging the PCB rings is always present. What do you mean? If I make a last test with an audio probe before desoldering could be an option? Is the absence of signal when the pedal is engaged a clear sign that the regulator is the problem?

[Ariosto]

Well, I received 5 new voltage regulators today and gave them a try, but apparently that´s not the problem because I still don´t have voltage in the PCB......