SE Electronics Z5600a II PSU

[nmcbennett]

Hi,
This is my first post on here. I just got a Z5600a II for a good price but have a slight concern regarding the PSU. On powering on the LED flashes at a low frequency for some 10 seconds or more and then stays on green which is expected behaviour. However when it is on (not flashing) it is still "pulsing" at the same frequency. i.e it looks like it's still receiving the oscillator voltage in addition to the stable supply voltage if that makes sense. I see a 555 timer in there but the schematic posted here before is not very easy to read. Can anyone verify whether the oscillator should remain on after the warm up period? I would expect it to turn off as you might expect some switching noise. Or if anyone else has this microphone perhaps you could take a look at the PSU LED and let me know if it flickers when on.

Many Thanks
Neil

 

[gyraf]

I see a timer and a flip-flop for blinking LED in the (poor) schematic I have. It's on a separate power circuit, so I wouldn't worry too much about it...

Jakob E.

 

[nmcbennett]

Thanks Jakob I guess you're right - if only I didn't have this OCD problem 

 

[saint gillis]

Hello, here's the PSU redrawn (reverse engineered from a MK1 unit)
Does anyone knows the values of the resistors on the pattern switch? I have to replace it and it's completely missing on my unit, otherwise I'll just put 150Ks ..

 

[Khron]

otherwise I'll just put 150Ks

Should be fine...

 

[innercityman]

Hello, here's the PSU redrawn (reverse engineered from a MK1 unit)
Does anyone knows the values of the resistors on the pattern switch? I have to replace it and it's completely missing on my unit, otherwise I'll just put 150Ks ..

Hi,

thanks for the redraw of PSU schematic. The one that Jakob have sent is unreadable. Can you confirm that R13 is a 2R 3W resistor ?

 

[saint gillis]

Can you confirm that R13 is a 2R 3W resistor ?

Yes, that's it !