GDemu resistor mod

[MondoGecko]

I've seen plenty of discussion on the GDemu and heat reduction, but I haven't seen much discussion on this particular method.

This is claiming that you shouldn't modify the power supply at all, which is a commonly suggested method, but instead add some resistors to the GDemu itself.

Thoughts?

https://www.delta-island.com/index.php/ ... supply-mod

[areyareadyherewego]

ymmv but I stuck resisters between the two pins for a while and made me feel a bit better than doing nothing at all until I got the works done: re-cap for PSU and main board, 9v rail removed on PSU, on controller PCB the fuse replaced and battery mod.. next to it Noctua fan as well.

[MondoGecko]

ymmv but I stuck resisters between the two pins for a while and made me feel a bit better than doing nothing at all until I got the works done: re-cap for PSU and main board, 9v rail removed on PSU, on controller PCB the fuse replaced and battery mod.. next to it Noctua fan as well.

I've done a few of these things; removed the 12v rail, controller board fuse+battery replacement, and I've got a Noctua fan and replacement thermal pads in transit right now. I'm not that worried about the heat because my Dreamcast tends to stay at pretty reasonable temps, the airflow is being directed out correctly and everything (I've added plastic to better direct air from the power supply to the exhaust), but it does still get noticeably warm, and I'd like to take preventative measures as best I can. The method I posted makes me consider reinstalling the 12v rail and adding resistors to the GDemu instead. I just don't know enough about circuitry to say if this method would be an improvement or not without testing it for myself, and there's like zero information about this method outside of the page I posted.

[areyareadyherewego]

ymmv but I stuck resisters between the two pins for a while and made me feel a bit better than doing nothing at all until I got the works done: re-cap for PSU and main board, 9v rail removed on PSU, on controller PCB the fuse replaced and battery mod.. next to it Noctua fan as well.

I've done a few of these things; removed the 12v rail, controller board fuse+battery replacement, and I've got a Noctua fan and replacement thermal pads in transit right now. I'm not that worried about the heat because my Dreamcast tends to stay at pretty reasonable temps, the airflow is being directed out correctly and everything (I've added plastic to better direct air from the power supply to the exhaust), but it does still get noticeably warm, and I'd like to take preventative measures as best I can. The method I posted makes me consider reinstalling the 12v rail and adding resistors to the GDemu instead. I just don't know enough about circuitry to say if this method would be an improvement or not without testing it for myself, and there's like zero information about this method outside of the page I posted.

oh if youve removed the rail, you're good. resister is a half step

but removing rail is superior method. I wouldn't fuss with it or sweat it

[Axel85]

Hi , why not replace the power supply with a Meanwell rpt-60 , It's almost a direct fit . You only need to wire the output to Dreamcast pins ( I've done it with an old atx connector recovered from a power supply) or solder them . And rewire the main line . Aside from those mods , some holes are just in the right place to screw it in . The power supply it's a medical grade device , it's made from a very trusty brand ,and super efficient . This way there's no need to put the resistor and waste current transforming in heat , and it's also an internal mod instead of pico psu

[MoeFoh]

I've seen plenty of discussion on the GDemu and heat reduction, but I haven't seen much discussion on this particular method.

This is claiming that you shouldn't modify the power supply at all, which is a commonly suggested method, but instead add some resistors to the GDemu itself.

Thoughts?

https://www.delta-island.com/index.php/ ... supply-mod

That's a link I've never seen before.

I chose to leave the 12v rail in tack. The part removed is actually a power pnp transistor and part of the switching power supply.

I went with the resistor method to provide a load for the 12v rail.

However, I went with a single 1K 3-5 watt resistor. That's right a single 1K resistor. It does gets warm to the touch as expected. Never had any heat issues.

[areyareadyherewego]

my DC was much cooler to the touch after removing the 12v but maybe the re-cap helped as well

ymmv

[MondoGecko]

I've seen plenty of discussion on the GDemu and heat reduction, but I haven't seen much discussion on this particular method.

This is claiming that you shouldn't modify the power supply at all, which is a commonly suggested method, but instead add some resistors to the GDemu itself.

Thoughts?

https://www.delta-island.com/index.php/ ... supply-mod

That's a link I've never seen before.

I chose to leave the 12v rail in tack. The part removed is actually a power pnp transistor and part of the switching power supply.

I went with the resistor method to provide a load for the 12v rail.

However, I went with a single 1K 3-5 watt resistor. That's right a single 1K resistor. It does gets warm to the touch as expected. Never had any heat issues.

From what I'm understanding of this particular mod it accomplishes the same thing as adding resistors to the power supply, but instead decides to tackle it at the GDEMU instead, which seems like a pretty solid and reasonable way to handle it. Also less chance of users zapping themselves on an open frame power supply!

I know the 12v rail has functions for PAL displays and RGB output, but I don't think I have any particular need for it in my Dreamcast so I believe I'll just leave it off for the time being. I think for future reference I'll be using this GDEMU resistor method in other Dreamcasts instead.