Pundit-R350 with Mobile P4m

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BillyBuerger
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Pundit-R350 with Mobile P4m

Post by BillyBuerger » Wed Aug 16, 2006 5:13 pm

I recently got a Dell laptop from a friend. It was her parents and was past it's warranty. It wouldn't do a thing when you pressed the power button. I noticed an odd high-pitched buzz coming from the area where the AC plugs in. It wasn't worth spending the money trying to figure out what part was wrong. So I thought I'd see what I could do with the parts. It had a Mobile Pentium 4m @2.0GHz and a 40GB hard drive. That's about all I could salvage out of it.

The hard drive worked fine still. It's not the most quiet laptop drive I've seen. But it's better than most of the old 3.5" drives I have laying around. I plugged the CPU into an Intel socket 478 motherboard and it booted up fine. At 1.2GHz though as Intel's desktop chipsets don't understand SpeedStep and run it at it's low power setting. But I was fine with that.

Then I saw a Pundit-R350 on eBay. That sounded like it would make a good HTPC. Small case, onboard VGA and DVI, SPDIF out.... I picked it up for about $120. Put all the hardware in, pressed the on button....... WOW! That thing was loud. I was planning on doing some modding. This confirmed it. I guess they had to make sure it could handle the 3GHz+ hot running CPUs. It was way overkill for what I wanted.

My first target was the CPU. I was a little concerned about the heat sink and the lack of a heat-spreader on the CPU. But that doesn't seem to be an issue. The locking mechanism doesn't require as much force as you would expect. But it seems to hold it down enough. You can see here that the thermal goop got plenty squished and looks to be making good contact with the heat sink.
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I wasn't using my stock Sempron 2600+ heat sink. And the fan is the same size. (well, not exactly) So my first step was to throw that on. That helped a ton. The included fan was noisy even at the lowest setting. Here's a picture of the Sempron fan and the included fan.
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That was enough to make the PSU fan more noticeable. Time to swap it for a 80x25mm fan. This was something I was pretty sure I was going to do from the start. I would have to cut out the back grill to make room for the larger fan. That includes the mounting holes. So I had to figure a way to hold the fan in place. Here's what I came up with....
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I put a piece of sheet metal along the two sides of the fan. After cutting out the fan grill, this fit right, but wasn't held in place at all. So I used two strips of foam (sticky on one side) and cut a slit right down the middle. The end of the PSU case would then slide in between the two sides of the foam. It works pretty well. The fan stays in place pretty good. I don't think it's really decoupled much. But it's already much more quiet and still seems to push plenty of air. It doesn't leave as much room behind the DVD drive, but it's enough.
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Now that the PSU is better, lets look again at the CPU. I noticed it was running pretty warm. Close to 60C on idle. That seems odd considering it's a mobile CPU running at 1.2GHz with a big chunk of copper on it. Then I noticed the CPU core voltage was running at 1.6V. This motherboard obviously isn't picking up on the voltage correctly. As it's suppose to be running at 1.3V full and 1.2V when idle. There are no options in the BIOS for any modifications. Crap. I've heard of people breaking pins and stuff to get a mobile P4m to run at 800MHz FSB. Looks like from the pinout that 1.6V is 00011 on the VID pins. If I connect VID1 and VID2, it should make it 00111 with is 1.4V. So I put a small bit of wire in the socket between those pins. It made a tight fit to get the CPU back in the socket. After crossing my fingers I hit the power switch. BIOS reports 1.4V. Score! Well then, if I also connect VID3 I'll get 01111 with is 1V. That might be too low but what the heck. It booted. But for some reason went back to 1.6V. Oh well, 1.4V is better than nothing.

It was still running pretty warm. So I decided I needed a bit more airflow. Since the stock fan was so bad, I couldn't see ever needing to use it. So it was sacrificed for the frame. That gave me the the mounting holes and height to lift an 80mm fan over the clips and such. It was actually a little too thick. So I cut the frame down by about 1/4th. My Panaflo L1 now sits on the heat sink and just fits inside the case.
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Since the fan was right against the case, the holes in the side were the only place for air to get out. But those holes weren't very big. The biggest ones where in the middle where the hub of the fan now is. So I drilled them out. It's a bit messy. Kind of lumpy and stuff. But now there's much more room for the air to get out.
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The only thing left was that the case was designed to stand upright. It came with a little foot thing that snaps to the bottom. But I want to lay it down. So I picked up some rubber feet and stuck them to the one side with double sided mounting tape. It sits up high enough that the fold down panel can open all the way.
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And that's it. Here's a few shots of the case now. I might need to paint the one side as it's unfinished metal. But that's just aesthetics. I can worry about that later.
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I do have to throw one little bitch out here about the case. Other than being loud of course. I was interested in the SPDIF out as I plan on plugging this into my stereo. Well, I didn't realize the SPDIF out was on the front panel. I don't know what engineer came up with that idea. But I can't think of any reason you would "want" that on the frot. USB, headphones, maybe microphone yes. But what would you be plugging into the SPDIF except to go to you stereo or speakers? I thought about trying to pull the connector off and seeing if I can route some wire to the back of the case and put it there instead. If not, I'll have to pick up a separate PCI sound card if I want digit output.

Thanks for reading.

jaganath
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Post by jaganath » Thu Aug 17, 2006 8:30 am

Well then, if I also connect VID3 I'll get 01111 with is 1V. That might be too low but what the heck. It booted. But for some reason went back to 1.6V. Oh well, 1.4V is better than nothing.
The P4M will POST at voltages as low as 0.835V @ 1.2GHz, so don't worry about going too low. It's a pity your current board doesn't undervolt but finding a S478 board that undervolts is fiendishly difficult now. If you want a list of the ones that do I have one hiding somewhere on my hard drive.

scrandman
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Joined: Wed Jun 15, 2005 10:06 am

Post by scrandman » Fri Aug 18, 2006 10:14 pm

Nice job, but it looks like you had a few slips of the drill when opening out those holes.

Bear in mind for future mods that drilling from the other side will mean that any slips are not visible ;)

BillyBuerger
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Post by BillyBuerger » Sat Aug 19, 2006 9:26 am

scrandman wrote:Nice job, but it looks like you had a few slips of the drill when opening out those holes.

Bear in mind for future mods that drilling from the other side will mean that any slips are not visible ;)
Yeah, it doesn't help that my drill batteries are dying. I could only do a couple at a time before there wasn't enough power to make it through. This also meant it left rough edges on the other side that I had to sand down. I would of had to sand off the paint had I gone the other way. Last, the case is U shaped. So I couldn't reach from the other side anyways.

scrandman
Posts: 41
Joined: Wed Jun 15, 2005 10:06 am

Post by scrandman » Sat Aug 19, 2006 8:18 pm

Aaahhh! I forgot that it wasn't a detachable side panel, but the u-shaped one.

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