Hi, turk 182. First of all, thanks for the interest.
Well, I was cleaning it with compressed air and isopropy alcohol, and power wires are released from board and connector (my mixer is 20 years old, I think). I solved them, but incorrectly:
Green (0v) -> P0 (in 17v)
Black (17v) -> P1(in 0v)
Red (17v) -> P2 (in 17v)
where the correct would be:
Black (17v) -> P0 (in 17v)
Green (0v) -> P1(in 0v)
Red (17v) -> P2 (in 17v)
[Obs.: P0, P1, P2 are points of connection in the board]
I turned on and it worked... for some seconds... so it burned my right earphone (it really got hot!), after a very loud noise e some smoke. Now I have:
- all mixer section is ok, balanced and unbalanced;
- everytime I increase MONITOR/HEADPHONE pot, VU leds turn on as the pot increases, even without any sound source and everything closed in mixer;
- I have lot or voltage at the master output (more than 12v, just right channel);
- I have same voltage both channels headphone output (but not monitor rca output);
I think I burned one or two ICs 5532 (maybe relative to the headphone amplifier, just right channel, I think).
As this board is doble-sides, very close components, I would like to take a good shot. I asked schematic to Soundcraft a few some days ago but they have not answered me yet.
If you can give any clue, I'm very grateful.
Regards
Well, I was cleaning it with compressed air and isopropy alcohol, and power wires are released from board and connector (my mixer is 20 years old, I think). I solved them, but incorrectly:
Green (0v) -> P0 (in 17v)
Black (17v) -> P1(in 0v)
Red (17v) -> P2 (in 17v)
where the correct would be:
Black (17v) -> P0 (in 17v)
Green (0v) -> P1(in 0v)
Red (17v) -> P2 (in 17v)
[Obs.: P0, P1, P2 are points of connection in the board]
I turned on and it worked... for some seconds... so it burned my right earphone (it really got hot!), after a very loud noise e some smoke. Now I have:
- all mixer section is ok, balanced and unbalanced;
- everytime I increase MONITOR/HEADPHONE pot, VU leds turn on as the pot increases, even without any sound source and everything closed in mixer;
- I have lot or voltage at the master output (more than 12v, just right channel);
- I have same voltage both channels headphone output (but not monitor rca output);
I think I burned one or two ICs 5532 (maybe relative to the headphone amplifier, just right channel, I think).
As this board is doble-sides, very close components, I would like to take a good shot. I asked schematic to Soundcraft a few some days ago but they have not answered me yet.
If you can give any clue, I'm very grateful.
Regards
if power supply connections where swapped then it undoubtedly has damaged components.
i see now why a schematic is needed.
looks like you will need to rebuild the power supply along with replacing components.
sorry i don't have schematics or much more to offer as troubleshooting advice.
i'm surprised you haven't heard from Soundcraft as a whole they are usually forthcoming with service info.
i see now why a schematic is needed.
looks like you will need to rebuild the power supply along with replacing components.
sorry i don't have schematics or much more to offer as troubleshooting advice.
i'm surprised you haven't heard from Soundcraft as a whole they are usually forthcoming with service info.
No. Nothing from Soundcraft. But I think I found the problem. I get Folio Lite sch, it's a bit different, but it helped.
The opamps of Notepad (headphone/monitor amp) have +Vcc and -Vcc controlled for two zener diodes, that decrease 24v to 15v. They burned when I reversed the poles. So we had 24v of there, consequently opamps are burned too.
Today I'm going to change these components and review everything, maybe I have found the problem.
Best regards
The opamps of Notepad (headphone/monitor amp) have +Vcc and -Vcc controlled for two zener diodes, that decrease 24v to 15v. They burned when I reversed the poles. So we had 24v of there, consequently opamps are burned too.
Today I'm going to change these components and review everything, maybe I have found the problem.
Best regards
Solved!
The occurrence is above. Just two ICs burned (IC10 and IC11), responsible for headphone and monitor outputs. Caps and zeners ok.
I think the ICs would transfer the input voltage (VCC+ and/or VCC-) to the outputs (OUT 1, OUT 2), because of this I had a relatively high voltage at the headphone/master right channel output.
Well, if someone needs, schematic of Soundcraft Folio Notepad below.
Thanks to Richard"Rick" Morris, Soundcraft Customer Service Technician.
;-)
Copyright violation. Attachment removed by Moderation
The occurrence is above. Just two ICs burned (IC10 and IC11), responsible for headphone and monitor outputs. Caps and zeners ok.
I think the ICs would transfer the input voltage (VCC+ and/or VCC-) to the outputs (OUT 1, OUT 2), because of this I had a relatively high voltage at the headphone/master right channel output.
Well, if someone needs, schematic of Soundcraft Folio Notepad below.
Thanks to Richard"Rick" Morris, Soundcraft Customer Service Technician.
;-)
Copyright violation. Attachment removed by Moderation- Status
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