OK then,MT47H64M16 is about RMB ￥ 17 here in China,it's about 3 USD. I'll buy 4 and try to replace them after the end of this semester. but what worries me is the small chip located at the edge of the board(near the last RAM chip),it looks like a SPD ROM
在 2012年11月16日星期五UTC+8上午6时13分41秒，trag写道： > > > > On Wednesday, November 14, 2012 11:47:32 PM UTC-6, willx wrote: >> >> >> I think it's not a jack connection problem,my ATV will show the RTL >> enternet card when I type lspci,but if i type ifconfig,there is no eth0. >> I have 3 ATV, the other two will show eth0 even if there is no enternet >> cable plugged in >> and I have decided to use that one as victim~ >> here I'm in China,and a second-hand DDR2 ram is more cheap,for a 1GB one >> with 8 chips,only costs about USD$8,so my question is, how to figure out >> the chip on the ram is fit or not >> > > Other than simple things,I'm out of ideas for the ethernet. I would > double check the power supplies to the RTL8100. Pins 3, 7, 20, 26, 41, 56, > 71, 84, 94 and 107 should be at 3.3V. Pins 12, 32, 54, 78 and 99 should > be at 2.5V. Also, double check your soldering. Exam the chip visually > under magnification. If you have the patience, check the continuity > between the pins where they enter the chip body and the associated pads, > and neighboring pads. > > Regarding the RAM, I do not think that you can salvage the necessary RAM > from a DIMM. The RAM chips on DIMMs are either 4 bits wide or sometimes 8 > bits wide. The ATV1 uses four 16 bit wide memory chips. > > Using Micron as an example.... Micron makes DDR2 memory chips in three > capacities, 512 Mbit, 1 Gbit, and 2 Gbit. But each of those total > capacities is manufactured in three organizations. The memory chip may be > 4 bits wide, 8 bits wide or 16 bits wide. > > So, a 512 Mbit chip which is 4 bits wide has 128M addresses. 8 bits wide > gives 64M addresses. 16 bits wide gives 32M addresses. The latter is > what was used in the ATV1. > > The Micron part number for 16 bit wide, 1 Gbit and 2 Gbit chips are, > respectively: MT47H64M16 and MT47H128M16. > > Note the trailing 16 in the part number and the 64 and 128 in the middle > of the part number. 64M X 16 bits. 128M X 16 bits. > > There are additional characters after the 16 in a real part number, > denoting package type, speed, temperature range, and revision. Anything > as fast or faster than 3.75ns should be fine (-37E or faster). I think > that -25 or -25E is much more common now days. > > The package will be 84 ball FBGA. The 60 ball package does not have > enough pins to support the 16 bit width (16 data pins needed). > > The writing on the package will not use the above part numbers. You need > to use the Micron FBGA Decoder > Micron FBGA Decoder <http://www.micron.com/products/support/fbga> > > to translate between the part number written on the actual package and the > long part numbers discussed above. > > If you do not have them, get the datasheets from Micron for 1 Gbit and 2 > Gbit DDR2 memory. Looking over the datasheet helps a lot. > > BTW, I recently investigated a little further into the possibility of > replacing the RTL8100 with the RTL8110 or maybe 8111. One of those has a > version for which RealTek's literature claims it is pin compatible with the > RTL8100. However, while the chips are "pin compatible" the 8110 uses > several of the NC pins on the 8100 as new power pins for 1.8V and > additional connections to the RJ45 jack are required. One could drop in > the more capable chip, but one would have to run a bunch of rework wires to > various pins to get it functioning. > > Interesting about the extra VRAM. I missed that. > -- To post to this group, send email to [email protected] For more options, visit this group at http://groups.google.com/group/atv-bootloader?hl=en
