I'm using my first post on this forum to thank LightFoot for the great job he has done on this topic and for the work he did on my Jally.
I am one of the customers he mentioned in his post that he worked on this week. In fact, I think the pictures are of my upgraded Jally.
I originally ordered my Jally in July as a 5Gh unit. I almost gave up hope when it finally arrived early in December. I was pleasantly surprised to see it hashed at 7+ Gh/sec.
But, in the short time I've had it, its bitcoin mining rate has dropped from almost $4 USD/day to maybe $1/day. Some of that drop was because the exchange rate was very high when I started and has settled, but most of the drop is because of the difficult rate increasing around 30% per week. It was clear that I needed to upgrade soon before the killer 300GH and 600GH machines hit the streets in February or more likely March or later.
In following this topic for a few weeks, I decided that upgrading my Jally from its original 2 chips to 5 would be the best compromise between cost and complexity. Going more than 5 sounded like I'd have additional cooling costs initially and ongoing. The major change the 5 chips makes is needing an upgraded power supply. Since my original one blew up after the 1st week and I had upgraded to a PC Power supply, I was ready. So, I purchased 3 chips from EBay.
But, I wasn't certain I wanted to risk ruining my only miner and I couldn't afford to purchase a spare one to upgrade. I noticed that LightFoot indicated that he would be willing to upgrade other people's Jallys. So, early last week I sent him a PM asking for information, timing, and costs. He responded quickly and I felt the price was reasonsable. It happened to match almost exactly the amount of bitcoins I had successfully mined since December. I decided it was a good sign and boxed my Jally up on Wednesday night a week ago and sent it to LightFoot USPS Priority 2 day. Had my coins transferred to my wallet from Eligius and Eclipse and when everything was there, I sent him the coins on Thursday.
He let me know when the Jally arrived, kept me updated with messages and even pictures throughout the process, and was patient enough to answer my million questions. Most of the time it takes is shipping, the next largest is testing/burnin before and after. He was very careful and didn't do all the chips at once. He tested between additions.
He sent the Jally back to me on Wednesday and it arrived today. It has been running for almost two hours and is hashing away at 18.3Gh. I think it will make it eventually to 19Gh.
One pleasant surprise for me is that the hardware error rate is much lower. I was averaging 4%+ because one of the two original chips had an error rate of maybe around 8% and the other was under 1%. I would see a new error at least every minute, so was wasting some of the hash rate on errors.
Now, I've only had 16 hardware errors total in the last two hours and the rate is .07%. I believe this is because LightFoot does a better job than BFL does in installing the heatsinks and perhaps because the soldering of the new chips may have reheated and improved the connections and surface contact of the original chips. I don't know if LightFoot has experienced this in his other upgrades, but I'm sure happy it happened on mine.
All-in-all it was a very pleasant experience and well worth it. The hardest part was not being able to mine effectively for a little over a week (I had a couple antminers going to help keep away my withdrawal symptoms during that period).
Thank you LightFoot...
Bill