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 733 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.
4MB STFM 1.44 FD- VELOCE+ 020 STE - 4MB STE 32MHz - STFM 16MHz - STM - MEGA ST - Falcon 030 CT60 - Atari 2600 - Atari 7800 - Gigafile - SD Floppy Emulator - PeST - HxC - CosmosEx - Ultrasatan - various clutter

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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?
Falcon ct60e 060 - 256mb ram - phantom bus and dsp accel // Atari TT - Thunder and Storm IDE 64mb ram - Lightning VME - USB LAN - Ati Mach64 2mb // Atari STM 4160 - 4MB ram - 16Mhz exxos 1.5 booster - Ultrasatan

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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!
Falcon ct60e 060 - 256mb ram - phantom bus and dsp accel // Atari TT - Thunder and Storm IDE 64mb ram - Lightning VME - USB LAN - Ati Mach64 2mb // Atari STM 4160 - 4MB ram - 16Mhz exxos 1.5 booster - Ultrasatan

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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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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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