Thanks Samuel. I'll be talking in more depth with OLPCA about this. Any suggestions on how to deal with this in the meanwhile are welcome :)
I have found that it can help to bend the spreader near the screw points to make it slightly concave. However, I agree with you that this is not a good recommendation for deployments. Sridhar On 23 July 2011 12:18, Samuel Greenfeld <greenf...@laptop.org> wrote: > The "unused" hole actually is filled by one of the screws which holds in the > rear plastic panel. That's why the screw holes which only secure the heat > spreader have arrows pointed at them. > > The fanciest (newest?) XO-1.5 heat spreader design I've seen adds a support > bar up to the green screw hole above near your area of concern, again filled > by a screw used to secure the back cover. I'm not certain though if this is > the design John is referring to, but I have seen a few XO-1.5s with it. > > It may be possible to bend the existing heat spreader in a certain manner > which solves the problem. But I would *not* be someone who could recommend > this approach for deployments. > > Some of OLPC's hardware engineers may be traveling this weekend, so I'm just > trying to provide you with a quick explanation in the meantime. > > > > On Fri, Jul 22, 2011 at 9:55 PM, Sridhar Dhanapalan <srid...@laptop.org.au> > wrote: >> >> All of the XOs I've seen have three screws on their heat spreaders. >> I've attached an annotated image. Hopefully the lists don't strip it >> out. >> >> There is an unanchored screw point in the bottom-left. However, the >> danger area is at the top, particularly in the top-left. This affects >> contact between the heat spreader and the Companion Chip, and might >> also be affecting contact with the CPU. Do the four-screw versions of >> the heat spreader address this problem? >> >> Thanks, >> Sridhar >> >> >> >> On 23 July 2011 01:21, John Watlington <w...@laptop.org> wrote: >> > >> > Do your heat spreaders have four screws or three ? >> > >> > The final heat spreader for XO-1.5 production had four screws >> > holding it down, to ensure a good fit. If your heat spreaders >> > only have three, OLPCA should be able to get proper replacements >> > from Quanta. >> > >> > Regards, >> > wad >> > >> > On Jul 22, 2011, at 10:35 AM, Sridhar Dhanapalan wrote: >> > >> >> We are currently engaged in changing the motherboards in over a >> >> hundred XO-1.5s. In many cases, the XOs are failing the heat spreader >> >> test afterwards. >> >> >> >> However, we can get the test to pass if we press down on the lid, >> >> behind the screen. This suggests to me that the heat spreader is not >> >> in proper contact with the chips. >> >> >> >> Without the lid plastic affixed (heat spreader exposed), we can see >> >> that the spreader is not touching the chips properly. We have tried >> >> bending the metal slightly near the screw points, but the contact >> >> doesn't last. >> >> >> >> Is there any way that we can deal with this better? We are changing >> >> the motherboards in these XOs because they have succumbed to >> >> overheating. I want to avoid that from happening again. >> >> >> >> Thanks, >> >> Sridhar >> >> >> >> >> >> Sridhar Dhanapalan >> >> Engineering Manager >> >> One Laptop per Child Australia >> >> M: +61 425 239 701 >> >> E: srid...@laptop.org.au >> >> A: G.P.O. Box 731 >> >> Sydney, NSW 2001 >> >> W: www.laptop.org.au >> >> _______________________________________________ >> >> Devel mailing list >> >> Devel@lists.laptop.org >> >> http://lists.laptop.org/listinfo/devel >> >> >> > >> > >> >> _______________________________________________ >> Devel mailing list >> Devel@lists.laptop.org >> http://lists.laptop.org/listinfo/devel >> > > _______________________________________________ Devel mailing list Devel@lists.laptop.org http://lists.laptop.org/listinfo/devel