Quote from: amix on April 28, 2014, 06:36:05 AM

Quote from: happydaze on April 28, 2014, 04:17:21 AM

I tried rmod on a second gridseed today after having it working well on another gridseed for several days. This one already had vmod1 and I was adding 15k. Actual measured numbers were 35.83k + 14.92k = 50.75 tested on board. That is on the high side I know.
I got the clicking noise and tried to redo a few times but couldn't solve it. I'm not good at soldering but thought I did an ok job. Voltage was low on first try 1.3 something. Second try had the voltage at 1.63v. I removed vmod1 but the clicking was still there. You can actually feel the clicking. The first pod I did had a higher value large silver capacitor 16v 330. This pod has 16v 220.

I screwed something up though on one of the later tries. I may have bridged to that 20nf capacitor. It got hot quickly ..... some solder has actually come out from under one of the gc3355 chips on two sides! Shocked

These little things are pretty tough. One chip of the five is still working so hopefully I can fix it up.

Summary:
rmod removed, bridge replaced, no clicking sound
It powers up and miner software sees it. cpuminer reports 5 chips and sets the frequency.
Only one chip does any mining and those shares are accepted by pool. (only chip #4 works)
Red light blinks very very slow. It can be off for a long time or on for a long time. This might be caused because only one chip is actually mining.
Solder is visible on two sides of the center Gridchip (one of the mining chips). See photo. It covers four or five pins on one side and maybe three on another side. I did not drop solder there and I know it wasn't there earlier because I took a photo of the new resistor in place before trying it. I think it has come out from under the chip if that is possible. How do I remove that?

I need some advice or suggestions on what to check / what to do so I can try to recover it or at least get a few more chips working. Any help will be greatly appreciated.

firstly clicking is prob the crystal i got it when i did the r52 mod with a 56k resistor. Applying slight pressure o. The crystal lessened it i reworked. It was less. I then uninstalled my grid dricers - i was getting an uart open error - and checkdd the box to delete the drivers. Tge dud a fresh install of the drivers. It sorted it. I aslo noticed havibg several instances of grid miner software cancause issues!! Byt it ciuldve been my drivers agsin.

As for the dolder o. Your chips thats from underside of yhe gtids. It connects the thermal plate under the grids to the theal vias. This is something i mentioned way back. Appears they used eithrr normal solder and tinned the pads or too much solder paste. On mine it was leaking o. The underside on several chips i had balls o tge thermal vias!! Try reworking it but first check the underside of your pcd make sure the thermal viad are clear. You might want to remove any dolder fro. The underside first. Hot air rework would do nicely alibg with flhx and desolder braid. To remove the doldrr balls o top flux and desolder braid. Either hit air it and remove the balls or a very fine solder tip. Rither way you need to be carefull. Chances are you might end up unsolderi g a fws pins. Resolder them with a fine tip. Remember to applyf
Flux to the pins beforehand and ti you tip.

Google smd remove. Theres a few you tube videos out there thatll be able to show you. It sint eady though so pratice on somethi g else first.

Dud wolfey invent the mod?? Er no wad someo e else he jyst gyessed what they wsd up to. Slthough i had the idwa of the r52 mod first. Others jyst tested it and put it into practice furst.
When overclickibg make sure you have fan cooling and even improved thetmsl pafs/paste especailly on the u derside!!!!!

IF I understand your scribble, no, I didn't invent the mod, obviously. Evidently neither did Nemercry based on his being accused of copying it from someone on another forum. Maybe it was your idea originally but you didn't fly with it so others took up the task since several of us were looking for a way to overclock our pods.
I never claimed any of the mods were my origination! Never! But I did come up with a simpler way to change R52 (R139) using a standard 1/4W axial resistor, and I came up with the most efficient value of 49.9k where power usage and max profit go. I also came up with the 5V USB mod.
Some say that 47k works the best for them but I doubt they can achieve the same results with the same low number of HW errors or less.
Anyway, this is all part of a group based evolution to achieve an end result for the benefit of all miners. My goal was 24/7 operation and maximum profit from my miners. I have achieved this weeks ago now and I am happy with the results. R52 mod IS the ONLY way to go IMO and I'm sticking with it. Wink