so all these stats are pretty meaningless without screen shots of the hasrate provided on the pool. i can overclock my gridseed to 800khs and only a 12 hardware errors over a 17 hour period. but my pool stats my has rate is 240. accepted shares are quite high though and the rejects - pool end - is not too bad about 3% the accepted share rate. i even managed to clock mine to 1.2 Mhs the other day it was running stable over night no hardware erros but again pool hash rate was down to about 230. the % of rejects was quite low to about 2-3%. and thios is without and hardcore hardware mods. so ill also wait to see how things pan out. Plus i dont get how the 4 different resistor values from basically shorting 2 jumpers. surely if jumper 1 and 2 (vid0 vid1) is shorted there total reistance should be a result of vid1 shorted and vid0 shorted, depending where there are in serail or parrell, itd be vid1 + vid0 (serial ) or 1/ ( 1/vid1+ 1/vid0 ) ) - for parell. Or am i missing something. at the moment i dont want to stop my grid from mining to check the layout of the tracks. ill wait till my next one arrives.
I do believe that a resistor swap will help though but need to examine it more though.
Oh and i also believe the reissotrs are SMD series 0403 - whihc aint a problem as i have a smd work station, hot air rework and soldering iron.
EDIT. DUH - sorry back tracked a bit :
Could this be done via graphite pencil mod?
Possibly, though the pencil mod will decrease resistance, whereas we want the opposite (on the particular resistors I'm looking at). It might be possible to target a different resistor. What this mod is doing is setting vid1 = 1 (solder part) and vid0 = 1 (voltage=1 part). Vid0 and vid1 are connected to a 2-bit VID buck converter, which selects between four output lines (set0, set1, set2, set3). On my miners, the resistance of the resistors connected to these lines are 33, 30, 27, and 36 K (this is different than gridseed's PCB spec!). By default vid0 = 0 and vid1 = 0, so you get 33 K. I experimented with all four vid0/vid1 values and found that power usage (and thus core voltage) is proportional to resistance.
https://github.com/gridseed/usb-miner/blob/master/hardware/GC3355%20USB%20for%20release.pdf?raw=true| vid0 | vid1 | W | R (K) |
| 0 | 0 | 12.4 | 33 |
| 0 | 1 | 10.4 | 30 |
| 1 | 0 | 11.2 | 27 |
| 1 | 1 | 14.0 | 36 |
ding penny drops now i see it the combo. intresting enough on the 8 chip sycmatic i have SET3 36K, set2 33k, set1 30k , set0 27k (R66,R64,R63,R139 respectively) whihc are labeled as Not connceted expect set3.