Too Hot for My Chinchilla

I got a few emails from GDEMU owners, mostly asking for help with various issues, and I figured some additional clarifications are in order:

GDEMU does not remove region lockout. In other words, your Dreamcast will refuse to boot games from other regions just as it would refuse original GD-ROMs. This is on purpose, because…

Even patched to allow all region booting, some games will not work. This has nothing to do with GDEMU, it’s in the game code. Most games can be easily patched but some require a specific video output to be present – for example, USA region game might not work with RGB cable which is pretty much the default in EU. And there are a few titles that will just not work in non-native region, period.

In general it’s strongly recommended you stick to games for your region, and if you want to experiment then at least check how the original behave before you blame GDEMU. Seriously, get a clue, it’s starting to get annoying having to explain this over and over again.

Lately another issue popped up, apparently Dreamcast power supply unit can get a bit hotter when using GDEMU instead of the original drive. I never had that issue and it wasn’t reported by anyone else so far, but I suppose it’s possible that without the drive blocking off most of the direct route from the back of the unit (where the “gills” are) to the fan in front, the PSU gets less airflow around it. I’ve been running GDEMU – it’s various versions – for many, many hours now, including no cover and open lid / not fully closed lid situations. I’ve never noticed the case to be strangely hot but I did not actually measure the temperature on the PSU itself. The report I got claimed it could heat up to just below 70°C. I don’t think it’s a problem, if you look at the design you will notice it never got any significant airflow either way and worked just fine. But for those worried I suggest you put a piece of cardboard screen fashioned to form a tunnel between the back, the PSU, and the fan. Do not remove that plastic cover though, it’s there to make sure the metal heat spreader is well insulated from mains.

22 thoughts on “Too Hot for My Chinchilla

  1. I found what i think is the same thread as you claiming it got upto 73c, Was wondering if it was anything you had experienced, which obviously, you havent, which is good. Was something that cought my eye. Glad you addressed it🙂

    Have you decided if there will be a new production run? If so, roughly when it will be, I keep checking here everyday, determind not to miss it.

    Many Thanks.

  2. All I can say for now is that I will have some leftover parts after I’m done with this production run – the result of my supplier delivering some items very, very late, so I had to find a second source for those. I would really like to get rid of them🙂

  3. Glad you mentioned the heat issue. I’ve tested a couple of different Dreamcasts and both of the PSU’s get up to around 68-69c with the GDEMU in there and the case on after 1-2 hours(slight electrical smell comes from the DC at that temp which had me worried). With the GD-ROM drive in running the same game(Crazy Taxi) it gets to around 50-56c(after 2 hours) and finally with the GDEMU in there and the case top off it seems to run at about 45-55c(ran for 4 hours and not much of a temp change).
    All documented on this thread as well as reasons 70c is too hot for the DC:

  4. How much amperage GDEMU draws compared to GDROM Drive, is this the reason of the overheating PSU or it is only the airflow?

    • GDEMU draws about 1W, which is way less than a GD-ROM drive. That too could be a problem for PSU, as it now doesn’t have any significant power draw over its 12V line so it works in a bit less efficient mode perhaps. But that would be just a contributing factor, not the source of the problem.

      PSU in DC was never well ventilated, the case doesn’t have any holes on that side like Saturn does. Even a tiny difference in the air currents inside the case can easily change its thermal balance. I still say 70°C is not a big problem yet – I mean look at the “brick” PSUs, fully enclosed in plastic with zero holes – but obviously the cooler the better.

      • Is it only the GD-ROM that uses 12V? (Is it required in the video i/o for SCART?) If it is, maybe that portion of the PSU can be isolated/disabled. Might make for a cooler, greener DC.

      • Video output and I think the fan as well use 12V rail.
        Really, a well placed fence and/or a few 3-4mm holes in the right spot at the left side of the case would help direct the airflow a lot. PSU in DC is always running a bit hot due to how it’s placed.
        On the plus side, now the motherboard is getting better cooling🙂

  5. To address the overheating PSU issue that seems to occur, I drilled a bunch of holes in the case to the left and top of the case under which the PSU is situated, removed the lid, and stuck a big fan over the hole above the GDEMU. It makes changing files a bit unwieldy, but the PSU is nice and cool.

      • If nothing else, it gives the 12V line something else to do… and I had fun trying out different fans…

  6. I’m going to make a ‘tunnel’ out of plastic or card as suggested, but adding the extra fan also interests me… I have 0.01% knowledge of electronics, but I own a soldering iron! My level of expertise so far has been single switch region modding an MDII twice successfully; how hard would it be for someone of my level of ‘expertise’ to locate the 12v line and install an appropriate fan? This does perhaps seem a little overboard, but also fun!

    Would it be possible to do this without too much cosmetic disruption?


    • I would give it a go, it’s fun and not difficult. You can go overboard like I did or do something more tasteful if you like. Afterwards, your DC will feel more personalised.

      You just need to identify the voltages coming from the power supply by touching a multimeter to the little prongs on the PSU side. Using a multimeter is easy and they are cheap.

      If you don’t want to bother with the multimeter and testing voltages and want to wing it, look up Dreamcast Power Supply Voltages on a search engine then click to see images.

    • Another fun and easy modification is getting an SD card extension adapter, cutting a notch in the DC casing and mounting the adapter along the edge of the casing so you don’t have to reach inside the DC to swap SD cards🙂

  7. Hi
    With my gdemu unit, I’ve got quite a lot of problems if I use my dreamcast with the cd lit closed: I cant use it too much because if I dont open the lit, I start having errors loading games, loosing textures, music or freezing games. It seems that exces of temperature dilates any component or contact so I start having those problems.
    Next time I will try the cartboard tunnel solution you propose.

    • I’d suggest checking voltages first directly on GDEMU. Really, it should be the very first thing to do because in 95% cases that’s the problem.

  8. But, if there is a voltage problem with my unit, what do you recomend then?
    I’ve got 2 dreamcast and both of them have the same problems.

  9. Usually taking the PSU out and cleaning the contact points to the motherboard (this is where it oxidizes) resolves the problem. Rarely the PSU is faulty and needs to be replaced or repaired.

    If cleaning doesn’t help and you can’t find (cheap) replacement then your only other option is to install some better, custom cooling. Not ideal but beats unusable Dreamcast.

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