PicoDreamcast
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chriz2600
PicoPSU remains on when switch is off, and Dreamcast Fan keeps running while system itself remains off.
It seems even on the 1.1 boards, the PicoPSU remains on when the power switch is off, and it keeps running my Dreamcast's fan (and any HDDs if I decide to connect them to the PicoPSU). I don't even think it always did this either, only recently started to happen (after I used it for a bit to power a spare HDD). Any idea what might be going on?
My PicoPSU is identical to the one you have in this screenshot: https://raw.githubusercontent.com/chriz2600/PicoDreamcast/master/assets/pico_dreamcast.jpg
Regarding your question asked on the commit page:
Does the resistor need to be soldered onto 1.1 boards? Or is this only for 1.0? I ask because my Dreamcast's fan runs while the system is off for some reason.
Yes, the resistor is needed to turn the system off properly. Version 1.1 just adds pads on top of the PCB for a resistor. If you have the resistor installed, make sure you can measure it's value between 12V and GND (disconnect board from Dreamcast and PicoPSU).
This is what mine looks like: 
It looks like there's something there, but the thing still doesn't turn off properly. I soldered a 47k (I would have done 10k, but I don't possess any.) resistor between the two directly before to see if it helps, but I didn't have any luck.
The odd part is, when I unplug the system entirely, and let any remaining power to drain, and I hook it up again, it still powers the fan and and whatnot when it's plugged back in, even with the switch off.
Ok, so when you remove the board from the console and unplug the PicoPSU, what do you measure between 12V and GND? 47k ohm may be too high, haven't tested that myself yet. You're saying you have a HDD connected to the PicoPSU, I assume it's connected to the extra header on the PicoPSU. Does it make any difference, if you leave the connector disconnected?
I don't have the tools to measure the current between them. I don't have an HDD connected. I did, but only temporarily as I needed a surrogate power supply to run a drive for a project. It was just using the included cable with the PicoPSU. That's no longer there, and there's no difference if it's present or not.
Sorry, my mistake, I didn't asked specifically what to measure: It's not the current, it's the resistance I'm asking for, just to make sure there is no bad connection between the resistor and 12V/GND (if you don't have a multimeter, just ignore this). Another question: Do you have a DCHDMI? If yes, is a HDMI cable connected? If yes, can you test without the HDMI cable plugged in?
I don't have a multimeter, sorry. And no, it's a standard, unmodified VA1 Dreamcast.
On Wed, Oct 9, 2019, 7:21 PM Christof Harnischmacher < [email protected]> wrote:
Sorry, my mistake, I didn't asked specifically what to measure: It's not the current, it's the resistance I'm asking for, just to make sure there is no bad connection between the resistor and 12V/GND (if you don't have a multimeter, just ignore this). Another question: Do you have a DCHDMI? If yes, is a HDMI cable connected? If yes, can you test without the HDMI cable plugged in?
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At this point, I have to assume, that the resistor itself or the connection is open (the connection from the resistor to the 12V and/or Ground), because the symptom you are describing (5V rail remains active, when PS_ON# is high) is exactly what can be observed when no resistor is present on the 12V rail. Unfortunately, without tools to do any test, it's not possible to troubleshoot properly. I think, best option is to ask the seller for a replacement.
I've tried multiple times to solder new 10k ohm resistors onto it, both with the designated pads, and between the two pins directly. Nothing worked, and eventually the solder pads on the PicoDreamcast were ruined due to so many times re-doing this. I can only assume the PicoPSU was faulty, or I did something to break it like the worthless idiot that I am.
Oh well, $120 down the drain. Shit.
I have the same problem unfortunately. I am fully modding my Dreamcast and have just installed DC Digital. Next was PicoPSU, now the Dreamcast would never turn off. I followed this thread and measured the Resisitor from the 1.1. design, has 10k as expected. I also checked the 12V/Gnd on the DC Connector, still 10k. I even moved the whole PicoDreamcast Setup into a stock DC, but no luck. I also tried with an attached harddrive, to the picopsu connector, made no difference. I am out of ideas now. Could the PSU somehow be broken? Or has something changend? I have the PicoPSU-80 if it matters, ordered via Amazon, where at least on Dreamcast User successfully adapted the PSU to the Dreamcast, without the PicoDC though.
I just got a PicoPSU and PD, and am having much the same problem. Regardless of the state of the power switch, the Dreamcast is fully powered. Resistor is present and measures @ 10K. I'm running a TerraOnion MODE, and the DC also has the DCHDMI installed, so could it be a load issue somewhere?
