Replacing the DC PSU

very nice, though I'm wondering why you're not using the PICOPSU PS-ON pad to control the power state?

i ran into issues with the Pico retaining power & thus not allowing me to power cycle fast. (I had to wait 5 seconds or so before I could power on again)

 

damn! I really didn't think of that, I just bridged the power-on pad with a ground for my testing and I didn't think it over, I just continued using it like that... might change it soon LOL

 

Thanks for the link - will be ordering one later today.

Well done on completing the mod nicely and cleanly.

Looks really good and will run nice and cool

 

hey i checked out that picopsu on ebay but there is only ones available from the us with a us plug and i live in the uk is there a uk version or a similar product i can get

 

^ either get a cable that fits and has a UK plug or cut and replace... the external psu is universal 100~240v

 

I closed the unit for final extended testing, I removed part of the plastic shell unde the gd-rom lid, it REALLY helped with heat and I think I can get away with just a 40x40x10mm fan between the heatsinks. Both are now cooler than when the upper shell was stock.



I also did not change my design to use the picopsu's ps-on pad I can power-cycle instantly so in fear I'll get the same delay as Rocky5 with the ps-on pad I left mine as is - soldered to always on and controlling the 12v feed.

 

now we just need an indepth guide

 

I think you may have misunderstood me, I got a delay by using the 12v line like yours, so I switched to the PS-ON pad & no longer get a delay. (My PSU is a 24pin & 160w so that maybe why it retains power)

 

^ ah... well I don't get this delay , maybe it's a 160W picopsu thing, some larger cap retaining some current or something. I thought the ps-on circuit did it.
I decided on adding a small exhaust fan after all, something behind the original grills but without a "tunnel" so there is no noise, just to help move some air out of the shell. Better be safe than sorry , will update with pics later.

 

You could run the stock fan at 3.3v & it's almost silent, it's what I have been doing for a long time & your DC won't black screen, well I can't say for hot countries since I live in Scotland & the hottest it gets here is like 28C lol

also what is the blue thing (resistor?) on the power switch as I never removed this when attaching the 12v line, I reused the PSU connector so I could swap & change easily. (Could that have caused the power retaining issue?)

I also made a little housing out of a CD spindle padder thing & hot glue, since I had no way of sticking it to the shield. (None permanently, also I couldn't do what you done since my external molex pinout is on the top side. (can be used to power an external HDD))
I also reused the original PSU pin connector, again this is in case I need to scrap this DC. (If I break something, no soldering is required)

I'm thinking of reusing the two prong socket & drilling out a hole for the power jack to get bolted onto, giving the system a stock look.

 

so the all the connector are from the original PSU?

the blue thing is for safety reasons to avoid electric shock

 

Hm, no idea the stock fan could run at 3.3v... I will try that and use it as an exhaust fan , atm I am using a low-rpm 35x35mm one and the results are awesome, after a couple of hours of SegaGT attract mode the heatsinks on my setup are slightly warm, the exhaust really works wonders.

Also the blue thing on the power switch is a capacitor, it's used for filtering out noise before electricity goes to the psu.

 

Correct, desoldered & wires attached. (Hot glued the power one, so none of the wires move)

Yeah, it even worked with the default PSU, but you got the electrical smell. (you know what I mean)

 

wtf??? why?

 

Not sure, what you mean by that?

But I will say this, its probably because the PSU wasn't getting adiquite cooling & it was getting hotter than it normally would, the DC ran fine & I never had an issue, I just didn't like the fact the top of the case got warm & if you sniffed the fan grill you could smell a warm electrical (protective component layer burning off?) smell. Like in the old days when you bought a new TV or Hi-Fi when you turned on for the first few times, you got that new electrical smell.

update, the smell comes from the PSU not the DC motherboard just clarifying that if that's why you were saying what you said.

 

oh yes, the nice smell of a psu working almost 100%
yeah the original psu is surely tweaked and limited to what the DC needs, anything extra and the heat fest starts.
I am now officially over with my modification, everything is perfect , only 2 things remain:
a. replace the 40mm scythe fan with a way better one from noctua
b. cut some noise-blocking foamy material and place it inside the lid's circle, on my setup I get noise because there is too much empty space LOL , puttin something foamy on the lid almost eliminates it.

 

Nice job keropi. Do you have anymore information about how to set up that 555 timer to trick the fan sensor? Thanks.

 

^ I just followed the info here: http://randomprojectman.blogspot.gr/2008/05/even-though-its-pretty-dated-system-i.html

 

Looks good. Thanks!

 

Does the VA0 model not have the RPM sensor? It only has 2 wires on the plug going into the controller board.