So. I've got two Sonnet Encore Duets 1.8 in my possession. One works perfectly, and the other one is broken. The broken one consistently kernel panics with memory mapping errors halfways through the boot process, and I've been scratching my head for a while trying to fix it - I tested it in various configurations, 100/133mhz bus, unplugging the fans, etc. but nothing seems to work.
Anyways, I had the idea that clocking it lower would make it usable. Unfortunately, there wasn't any public info about this specific model that I could find - probably because people don't want to mess around with a rarity like this - well, given that this one is practially dead, I figured I could try on my own. Thanks to the thread over at 68kmla, I cross referenced the various components to my own, using high res images I took.
I was able to both underclock and overclock by changing specific resistors, so I'll dump that information here. There's probably more configurations but I'm not skilled enough nor do want to push my luck
Here are some high res pics of both sides on the working Duet, as well.
I'm not sure how relevant R56 or R57 is, my machine refused to start with either of those changed.
In the end, underclocking the broken Duet didn't fix the memory errors, but it did delay the error from appearing. The problem seems beyond what I'm able to fix... so instead, I felt gutsy enough to try and overclock my working Duet. To my surprise, it started without issues and gave me the sweet number 2.
Additional notes.
Both of the Duet's were of different revisions, as indicated by the stamp on the copper heatsink. My working one is revision C, while the broken one (given by a friend) is revision A. There is only one difference (that I could see) between the two revisions: the resistor R60 (righthand on the connector side) is bridged on rev C but not A. I bridged it on A and it didn't break or affect anything. Given that it's under the voltage regulator (i think that's what it's called) it probably does something related to it.
Anyways, I had the idea that clocking it lower would make it usable. Unfortunately, there wasn't any public info about this specific model that I could find - probably because people don't want to mess around with a rarity like this - well, given that this one is practially dead, I figured I could try on my own. Thanks to the thread over at 68kmla, I cross referenced the various components to my own, using high res images I took.
I was able to both underclock and overclock by changing specific resistors, so I'll dump that information here. There's probably more configurations but I'm not skilled enough nor do want to push my luck
Here are some high res pics of both sides on the working Duet, as well.| Sonnet Encore Duet 1.8 | 1.4 | 1.5 | 1.8 (original) | 2.0 |
| R55 | - | |||
| R56 | - | - | - | - |
| R57 | - | - | - | - |
| R58 | - | - | ||
| R59 | - | - | - |
I'm not sure how relevant R56 or R57 is, my machine refused to start with either of those changed.
In the end, underclocking the broken Duet didn't fix the memory errors, but it did delay the error from appearing. The problem seems beyond what I'm able to fix... so instead, I felt gutsy enough to try and overclock my working Duet. To my surprise, it started without issues and gave me the sweet number 2.
Additional notes.
Both of the Duet's were of different revisions, as indicated by the stamp on the copper heatsink. My working one is revision C, while the broken one (given by a friend) is revision A. There is only one difference (that I could see) between the two revisions: the resistor R60 (righthand on the connector side) is bridged on rev C but not A. I bridged it on A and it didn't break or affect anything. Given that it's under the voltage regulator (i think that's what it's called) it probably does something related to it.
