Sorry for making an new thread but it doesn't seem like anyone read the KNC Forum or the other threads in this forum.
I have a few KNC Jupiters. Some of the modules have bad VRMs which result in decreased hashrate. I have one module which has 8 VRMS and all of my other modules only have 4 VRMS. All the 8 VRMS are working.
Can I desolder the VRMs from the 8 VRMS board and use those 4 to power up the modules with the dead VRMS?
I know its surface mount solder but I have the right tools and experience to swap out there parts.
Did you ever get some answer on this? I am in the same boat and I want to replace some bad VRMs with good ones, so I can get some modules back up to full speed. I tried de-soldering a VRM already and I couldn't get it so soften up to be removed. However, I was using a small head tip, so that may have been my problem then, but I am also not sure changing the VRM is the only this I need to do....
You need to use a hot air rework station to desolder, since its surface mount. It takes a very long time to heat up the solder since the points are big.
I left it the way it is because a module with 4 working VRMS uses almost the same power consumption as a module with 3 working VRMS. This is only a good job if you need the room for the extra module. So I just left it the way it was.
thanks for the input, however i don't have the equipment to properly de-solder surface mounted chips, so i am basically going to leave them as is. I was actually thinking of chopping the vrm's off the board with a needle nose snipper or a dremel, leaving just enough metal leg exposed to basically solder a replacement VRM right on top of that. It would look ugly as hell, but it should work in theory, but maybe not with 25 amps following through continuously. With a shady solder job like that, it will probably melt the board or burn up the chip, or both
Well I actually have 5 Jupiter November boards with 2 sequential VRMs dead each, so i basically have 1 die dead on each module. I also have one better one, with a few dead cores on one die on it, so combining them all together, i should have get around 700-ish GH/sec out of all of them. I am sure i can get up to 900-ish GH/sec overclocking even these limpy modules, so i will be good with that.
I then have 7 more modules with 4 or more VRMs dead and/or dead dies/cores, and i was hoping to cannibalize parts off those guys to get the other modules 100%; oh well.
well if i try to Frankenstein a replacement VRM on these modules in the future and it doesn't burn up, i will post those results here.
