Replacing the DC PSU

Yes. According to a couple of pages back, this is the best method, is it not?

 

I'm looking at everyone's picture and saw that they still have the blue MOV by the power switch. Is it necessary to remove?

 

Not necessary I don't think, but it isnt needed and is perfectly safe to remove.

 

I had that issues when using ground to turn the DC on and off. ( should be the live wire )

Grounding PS-On should be instant on and off.

I cannot tell where wires are going in the images.
( I just ground PS-On when the switch is pressed )

 

well reading a couple of pages back, it was mentioned that its better to short PS-ON and just wire the picopsu directly to the switch.
At the moment, I have the switch wired directly to the DC input of the picopsu.

 

You can do it two ways.

Power wire cut from the input ( red wire ) going to one of the switch wires and the other switch wire going to the other end of the cut wire ( red wire ) so you create a loop, if you use the ground wire instead, you get the waiting time between presses.

The other way is to not cut any wires and just wire the PS-On to one of the switch wires and wire the ground ( usually next to the PS-On pad ) to the other switch wire, creating a loop.

I use the PS-On method. Both have the same effect, I just didn't want to cut any more wires lol.

You can see what I done in this pic.

 

I have the switch wired to the red DC input wire. I still have to wait 20-30 seconds after switching off before I can switch it on again.

 

Both my DC and Saturn are wired up using the PS-On and it's instant on/off.

 

I guess it doesnt bother me THAT much. After all, who switches their consoles on and off and on again, unless you're testing a mod or something

 

Spent some time today trying to clean things up. I redid the connector (used part of the ATX connector from the picopsu)

 

I noticed you removed the blue cap thing that's used to steady the power signal, ( I think ) some one in this thread stated what it does.

That maybe causing an issue. haven't a clue as the way you have it should work fine, the pico shouldn't have any lingering power when turned off, so should be instant on off.

 

no idea then. The same things happens on my Saturn too

 

The 'blue cap thing' is probably a MOV, which is essentially a surge protector, and would be unnecessary on DC voltage lines.

 

i wonder if the dc adapter from ps2 can do the job. its output 8.5V 5.65A my dc have gdemu so the lack of 12v isnt an issue. ofcource before i install my pico i will use a multimeter to see if output 3v and 5v corectly

 

So I tried a new power adapter this morning, and it has significantly reduced the noise, but I can still see it faintly. The laser moving seems to influence it too to some degree. I'll see lines flicker on screen for a split second when the drive laser moves.

Edit: Quick update to say I've fixed the issue. A good quality power adapter is definitely a must, but I also tried wiring the 12v pin on the Dreamcast, directly to the power adapter, bypassing the picopsu all together, and that has fixed the issue completely (I wired it to the output on the power switch) I now get no interference at all.

 

So, I think we can safely say that the wires attached to the Dreamcast's power switch were picking up some interference, then propagating it through the system. That's definitely good to know!

EDIT: I think this was an incorrect assumption. =)

 

You think so? I was thinking maybe the 12v line through the picopsu is picking up noise from somewhere. It might explain why the Saturn doesn't show any interference, since it doesn't use 12v. the 12v line in the Saturn's picopsu goes through a 7809, to convert it to 9v.

 

Sorry, after re-reading your post, I think you're correct. I had assumed you fixed it by bypassing the Dreamcast's power switch, not the PicoPSU. The PicoPSU should be basically running the 12V through 5V and 3.3V regulators too. I wonder if the stock Dreamcast power supply had some additional filtering to protect against noise from the GD-ROM? You'd think the PicoPSU would have additional filtering, since the 12V line would often be connected to motors that drive spinning-mass storage, but I guess not!

 

mine does the same thing ... sometimes have to wait 10-20 sec for it to start up again .... do you have the 12 volt hooked up .. I don't since I have a usb-gdrom

 

Yes I still use the gd rom