FA-MAS' 360 laptop worklog and questions thread - 4/27

[FA-MAS]

So I'm planning an Xbox 360 Laptop and I've got a couple questions about the power supply and powering a monitor. I don't have any of the parts yet so I don't really know any specifics.

I know that most of the Laptops created just piggyback power for the monitor from the mains (full AC power) of the Xbox power brick for the monitor and just run it as if it were plugged into a wall basically.

I plan on using a Jasper Xbox and a Gateway 1775w monitor. From reading, the monitor operates off 12vdc and 5vdc. I've seen other threads about piggybacking these off of the Xbox motherboard. But it was advised the Xbox power brick can't handle the load on the 5v. I've also seen mods where the power brick was replaced by a PC power supply. My question is:

I should be able to do the mod to run the Xbox off a PC power supply, and pull 12v and 5v for the monitor right? A beefy enough power supply could power both and I wouldn't have the need for an external power brick. Would I be able to plain get rid of the power board for the monitor?

I also plan on running it HDMI to DVI from the Xbox to the Monitor. And have internal speakers. I understand there's something I have to do with the AV port on the Xbox to make audio go out through the stereo connection while still using HDMI. Can someone elaborate on how this is done for me?

[thetwoj1014]

I do not believe you would be able to get rid of the power board for the LCD. Though I admittedly know less than I should about that sort of thing, I just don't see it panning out correctly. Even if you could, a powerful enough PC supply is going to be bigger, weigh more, likely have a fan (added noise) and probably lack the specific protection circuitry of the 360 PS that I know saved my mobo from being fried several times :p I suppose all of that deals with personal taste, but overall it seems like it would just be less convenient.

I would definitely be interested to follow your progress if you do try eliminate the power supply though. Best of luck!

[FA-MAS]

I'm actually not too concerned about the size or weight. I'm actually thinking of using a FLEX ATX PSU that is 5.91" x 2.31" x 1.6" and was 200 watts. It looks to provide more than enough power for a Jasper Xbox. Plus It would weigh no more than carrying the 360 power brick and the fan would only be on when the system's on, just like the other fans so I think it would be negligible.

http://www.directron.com/fsp20050pla2.html" onclick="window.open(this.href);return false;

thetwoj1014: I actually had questions for you specifically. So you put the LCD power board in the bottom part of the laptop, would it have made it any taller if you had put it where you left the LCD driver and maybe just made the surround a bit bigger?

How did you guys wire up the AV port so it puts out sound even though you have HDMI connected? Also, how did you mount the LCD panel? You routed a recess in new front for the LCD and then sandwiched it between the front and back or did you make some brackets or use adhesive?

Do you have rough dimensions for the monitor's power board? LxWxD?

[FA-MAS]

This is basically what I'm looking to do, but also run the xbox off of it.

http://computerguru365.blogspot.com/200 ... nitor.html" onclick="window.open(this.href);return false;

Looking at Ben's making of one of his portables, Looks like I'll still have to split off the inverter board. I'd prefer to keep those with the LCD to avoid any issues with extending the backlight cables like you had thetwoj1014

[collinE]

The Jasper 360's power supply puts out 150w, which is more than enough to run the 360 unit by itself. I stumbled across THIS site showing that even when playing graphically intense games like Halo 3 and Gears 2, the draw was just under 106w. It's common practice for companies to include a power supply that can give more power than the system would ever need. If you ran the gateway 1775w (which uses 20w) off the Jasper power supply, you're looking at 130w still available for the 360.

I say you're good to use the 360 power supply, any of them, to power the screen. If you're already planning on using a different power supply, though, then never mind.

[FA-MAS]

I read in the forums that the actual Xbox PSU can't handle the additional draw on the 5v line. It said it only provides something like 1 amp. Which is the reason why I was looking at other power supplies.

[collinE]

Yeah, the problem is that I don't know how much the 360 or the monitor need from that 5v line. I was debating just using a spare 7805 regulator and wiring it up to the 12v line going to the monitor so that you'd get at least an amp from that and not take the chance of stressing the 360's 5v line.

Worth a shot.

[FA-MAS]

I'll probably end up trying the FLEX ATX PSU. The one I'm looking at can handle 16 amps on the 5v and 18 on the 12v

[thetwoj1014]

thetwoj1014: I actually had questions for you specifically. So you put the LCD power board in the bottom part of the laptop, would it have made it any taller if you had put it where you left the LCD driver and maybe just made the surround a bit bigger?

I don't think it would have made it any taller than the raised portion that was already present, however it would have necessitated making the raised area much larger which wasn't the look we were going for. If you designed your lid with that addition in mind though I don't think it would be bad at all.

*edit: On second though, it would have made it much taller. I forgot how tiny the driver board and caps were in comparison until I looked at some of the pictures on our blog. Power board + lid = very large lid.

How did you guys wire up the AV port so it puts out sound even though you have HDMI connected? Also, how did you mount the LCD panel? You routed a recess in new front for the LCD and then sandwiched it between the front and back or did you make some brackets or use adhesive?

We read through this build wrap up many times, in which Ben explains how he achieved the sound + HDMI issue. I would give you a specific answer, but honestly I don't remember. It's basically just grounding out certain pins, thus imitating what the Elite-audio dongle does and giving you analog audio with HDMI video.

http://benheck.com/xbox-360-laptop-3-elite

For our lid, yes we routed out 1/8" from our 1/4" komatex back piece, used super glue to adhere the back of the monitor casing to the komatex and then created a border on all sides with very thin 1/4" thick pieces of komatex and then on the very front was a piece of acrylic acting at the "top slice of bread" in our monitor sandwich.

Do you have rough dimensions for the monitor's power board? LxWxD?

Unfortunately I've got my entire life packed away right now as I'm moving over the next two days. If you're still looking for measurements next week I'll dig them up for you.

[bassmasta]

Yeah, the problem is that I don't know how much the 360 or the monitor need from that 5v line. I was debating just using a spare 7805 regulator and wiring it up to the 12v line going to the monitor so that you'd get at least an amp from that and not take the chance of stressing the 360's 5v line.

Worth a shot.

I'd recommend using the PSU. With a 7805, you'll have to heatsink it, as they give off a bit of heat, as well as place it in a circuit. Plus, I've heard they max out at 1A (in case you needed more).

[PhookYu]

So if the the total of watts is less then what the xbox 360 power supply gives off, I can connect the LCD directly to the power supply? Or do I still need to have the LCD's power board?

[collinE]

Yes, if that's the case, you can ditch the LCD PSU.

[FA-MAS]

There's gotta be a reason why Ben includes the LCD PSU in his portables though. Is it possible that even though the Xbox draws less power than the PSU says it puts out, that maybe the PSU isn't rated efficient? You know, like PC power supplies say they put out 300 watts, but it might only be 89% efficient so it wouldn't actually put out 300 watts.

[bassmasta]

There's gotta be a reason why Ben includes the LCD PSU in his portables though. Is it possible that even though the Xbox draws less power than the PSU says it puts out, that maybe the PSU isn't rated efficient? You know, like PC power supplies say they put out 300 watts, but it might only be 89% efficient so it wouldn't actually put out 300 watts.

Power supplies are least efficient at highest and lowest utilization. Its best to be in the middle.
I think he keeps the board for the backlight lamps-so they are able to draw as much as they need.

[PhookYu]

Do I have to connect the LCD power to the Xbox's power supply or can I possibly connect it to the power points on the Xbox 360's motherboard?