How to: recapping the Mega STe power supply

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Pacman
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Re: How to: recapping the Mega STe power supply

Post by Pacman » Wed Oct 16, 2019 8:27 pm

frank.lukas wrote:
Wed Oct 16, 2019 8:00 pm
Red Wire from the Fan to GND
Black Wire from Fan to -12V
OK. I think I've finally got it now ;)
See new illustration below:
Noctua fan connector corrected_final_correction.png
Noctua fan connector corrected_final_correction.png (16.63 KiB) Viewed 738 times
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Re: How to: recapping the Mega STe power supply

Post by exxos » Wed Oct 16, 2019 9:32 pm

I've gone back in this thread and updated the images. Possible we could clean up this thread in the future ?

The image looks OK to me now. GND is in effect the positive, because its at a higher potential than negative (-12v).
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Re: How to: recapping the Mega STe power supply

Post by Steve » Thu Oct 17, 2019 1:15 pm

I went inside my machine to swap the fan polarity, to see if it was exhausting the air in the right direction. Now I have no power, doesn't turn on at all. Not sure what to do :( Measured the voltages and they fluctuate between 0-1v.
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Re: How to: recapping the Mega STe power supply

Post by exxos » Thu Oct 17, 2019 1:21 pm

If the fan was running and you swapped the power, then it would have likely killed the fan.. you can't make DC fans spin backwards, they just smoke and die.
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Re: How to: recapping the Mega STe power supply

Post by Steve » Thu Oct 17, 2019 1:30 pm

You think the PSU won't turn on without a working fan?
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Re: How to: recapping the Mega STe power supply

Post by Steve » Thu Oct 17, 2019 1:46 pm

Okay, I think you're right. I put a new fan in and it has come to life again. Thanks Chris!
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Pacman
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Re: How to: recapping the Mega STe power supply

Post by Pacman » Thu Oct 17, 2019 8:18 pm

exxos wrote:
Wed Oct 16, 2019 9:32 pm
I've gone back in this thread and updated the images. Possible we could clean up this thread in the future ?

The image looks OK to me now. GND is in effect the positive, because its at a higher potential than negative (-12v).
Thanks for confirming.
So the fan "+" and "-" labelling on the PCB refers to the fan wiring (connect + from the fan to + on the "Fan +" pin on the PCB and likewise for -) regardless of the actual voltage.
Mega STe | MonSTer with dual IDE-CF memory card adapter | STe | SM-144 |NEC Multisync 1990SXi | IDE doubler | ST_ESSC | RSVE | ICD Link II | Link '97 | HD floppy drive/AJAX | HD floppy module | Minolta PCMCIA card-drive | Realtime Clock module | Discovery cartridge | Unitor-2 | Export | Combiner | Steady Eye | Human Touch | Unicorn USB

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Pacman
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Re: How to: recapping the Mega STe power supply

Post by Pacman » Thu Oct 17, 2019 8:20 pm

Steve wrote:
Thu Oct 17, 2019 1:15 pm
I went inside my machine to swap the fan polarity, to see if it was exhausting the air in the right direction. Now I have no power, doesn't turn on at all. Not sure what to do :( Measured the voltages and they fluctuate between 0-1v.
To try this you could have flipped the fan the other way round while keeping the electrical connections the same.
Mega STe | MonSTer with dual IDE-CF memory card adapter | STe | SM-144 |NEC Multisync 1990SXi | IDE doubler | ST_ESSC | RSVE | ICD Link II | Link '97 | HD floppy drive/AJAX | HD floppy module | Minolta PCMCIA card-drive | Realtime Clock module | Discovery cartridge | Unitor-2 | Export | Combiner | Steady Eye | Human Touch | Unicorn USB

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