My Dreamcast stays on only when the top shell is off

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Triple Lei
Posts: 376
Joined: Fri Apr 01, 2005 8:17 am

My Dreamcast stays on only when the top shell is off

Post by Triple Lei »

Been swapping cases a lot lately and I have no clue why this is happening now. Every time I press the power button I only get a little flash of power as shown from the power LED, plus a bit of the power-on beep, and the power goes away right when I lift my finger. My setup is an authentic GDEMU with the three resistors mod done to the original power supply, plus the Noctua fan/door switch mod.

Here's what I've narrowed down:

It's not me forgetting to attach the cable from the controller port to the motherboard. I've done that a couple times but even that would have kept the power on for at least a couple seconds.

It's not the power pins, as the power stays on with no top shell. But just in case I've already cleaned them with alcohol and nudged them towards the back since that's also supposed to fix/prevent the Dreamcast resetting.

It's not my 3D-printed tray knocking the GDEMU out of place. I'm using the same one in the video linked above; I like it because it doesn't use an SD card extension or block the LED pattern, both of which are necessary when updating the GDEMU firmware (that'll be another post). But I can't fit the top shell if the tray is screwed on too tight. So I took out the tray entirely, and tray or no tray, my Dreamcast only stays on without a top shell. Doesn't matter if I only have a bare GDEMU and I screw in the plastic spacer tightly or not at all; if the top shell's on, the power's off.

It's not the Noctua fan not running. The kit by Laser Bear gives you quite a long cable but I tuck the slack underneath the GDEMU, so there shouldn't be any part of the cable touching the fan not causing it to spin, which I've heard can also shut off a Dreamcast. I've tried putting in the stock fan too, leaving the door switch mod in place, and no difference.

It's not me somehow messing up the three resistors mod; it worked before I did the fan/door mod with a top shell on, and it works now without any shell, but the latter isn't an option... especially when I've poured so much into getting the shell that I wanted, and I've already proven that it isn't the fan.

Halp?
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matt
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Joined: Mon May 09, 2005 5:46 am
Location: Honolulu, Hawaii

Re: My Dreamcast stays on only when the top shell is off

Post by matt »

It really sounds like the power button isn't being depressed far enough?
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Triple Lei
Posts: 376
Joined: Fri Apr 01, 2005 8:17 am

Re: My Dreamcast stays on only when the top shell is off

Post by Triple Lei »

By gum, I think you're right! :shock: I put the top shell on, hit the power button, removed the lid, and saw that the power button wasn't actually pressed. I would have never thought to check for that because I was also careful to hit the power button a couple times to remove any leftover charge.

Right now I brought out an old hole puncher and an NES cartridge sleeve to slowly fill the hole in the power button. If there's something better I'm all ears...

---

EDIT: Got impatient and just stuck a wad of paper in there. Seems to work okay. Thanks for saving my bacon again!

EDIT 2: Opening up my other Dreamcasts, it seems that the true, true culprit was the power switch itself, which had a shorter pointy bit by like 2 or 3mm. Totally not the fault of the replacement shell. Buy from your preferred vendors (Stone Age Gamer, Muramasa Entertainment) with confidence.
Dreamcazman
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Joined: Thu Feb 24, 2022 11:07 pm

Re: My Dreamcast stays on only when the top shell is off

Post by Dreamcazman »

Triple Lei wrote:true culprit was the power switch itself, which had a shorter pointy bit by like 2 or 3mm.
I'm not sure how this happened, shouldn't wear down just from normal use. Is the case fitting together properly? Maybe check your GDEMU install as that can sometimes cause the lid to not sit down far enough.

If it definately is the switch and to make it a bit nicer as opposed to having paper stuffed in there, build up the switch a little using epoxy putty or something similar, then when cured, file it down to the correct length/height.

Or you could replace the switch altogether.
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Triple Lei
Posts: 376
Joined: Fri Apr 01, 2005 8:17 am

Re: My Dreamcast stays on only when the top shell is off

Post by Triple Lei »

Yeah okay, so I ended up switching the switch.

https://imgur.com/a/qJwSXNv

Difference in height is more like 0.5 cm.

Could've been wear and tear, but it didn't just erode. Look at how it's segmented... it's like they wanted you to break it off.

Will definitely look into properly repairing the bad switch. Thanks all... ~
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