GridSeed 5-chip USB miner voltage mod

[WorsAt5gPerDay]

Even one of my volt-modded (R52 47k) 5-chip GridSeeds went dead after mining on 1200MHz.
You can see separated positive lead. I forgot to take picture while it seemed there is burned area 3x3cm.
I didn't have any ISO to clean so I used cheap Etheric Oil to clean the burned area 
After cleaning I was really happy that there are only FB23 & FB24 burned and that I am not the only one left with melted ferrite cores.
Short question if I order 74792121 part from Farnell will it work? What can potentially happen if I brick it

I am mining on my developing machine with R9 280x, HD5870 and 5x volt-modded (R52 47k) 5-chip GridSeeds.
All together is powered with Platinum CORSAIR AX860. I don't want to burn my whole machine so what are FB23 & FB24 supposed to do and is there any risk to damage my PSU if i brick them.

Thank you in any advance!

http://i61.tinypic.com/2zs17jo.jpg

[1715202550]

1715202550

[CartmanSPC]

Hehehe, it's more profitable to mine BTC now...who would have thought?

Not taking electricity cost into consideration of course

[foz]

Even one of my volt-modded (R52 47k) 5-chip GridSeeds went dead after mining on 1200MHz.
You can see separated positive lead. I forgot to take picture while it seemed there is burned area 3x3cm.
I didn't have any ISO to clean so I used cheap Etheric Oil to clean the burned area 
After cleaning I was really happy that there are only FB23 & FB24 burned and that I am not the only one left with melted ferrite cores.
Short question if I order 74792121 part from Farnell will it work? What can potentially happen if I brick it

I am mining on my developing machine with R9 280x, HD5870 and 5x volt-modded (R52 47k) 5-chip GridSeeds.
All together is powered with Platinum CORSAIR AX860. I don't want to burn my whole machine so what are FB23 & FB24 supposed to do and is there any risk to damage my PSU if i brick them.

Thank you in any advance!

http://i61.tinypic.com/2zs17jo.jpg

Hmm that is interesting....I used this part from digikey for FB23/24 http://www.digikey.com/product-detail/en/742792121/732-4654-1-ND/4310394.  Mouser also had the part listed but it was backordered until mid August.

Unfortunately, I cannot verify that the part works because after making the repair, FB26 cracked and sizzled.  It was strange.  After the initial destruction of FB23/24 I could still hook up the usb port and have windows recognize the unit.  After the repair I only plugged in the 12v supply to test it...no sizzle so I thought I might be ok.  However when I plugged the usb cable into the unit(with 12 volt lead simultaneously), FB26, located near the usb port bit the dust.  I quickly unplugged before much damage was done...but there is clearly a crack in FB26 and some soot around the area.

What I cant explain is with the 12 volt plugged in, measuring voltage at the pins on the 12v jack, I get widely varying voltages from 0-12v.  So much so that the fan will only slightly move when the voltage spikes up to 12v and it wont even move a quarter of a turn.  It is possible that the 12v jack is bad or is there something else going on that I do not understand?

Anyone or maybe Wolfey have any ideas about what to try next?

Let us know how your repair goes Wors 

[ZiG]

Even one of my volt-modded (R52 47k) 5-chip GridSeeds went dead after mining on 1200MHz.
You can see separated positive lead. I forgot to take picture while it seemed there is burned area 3x3cm.
I didn't have any ISO to clean so I used cheap Etheric Oil to clean the burned area 
After cleaning I was really happy that there are only FB23 & FB24 burned and that I am not the only one left with melted ferrite cores.
Short question if I order 74792121 part from Farnell will it work? What can potentially happen if I brick it

I am mining on my developing machine with R9 280x, HD5870 and 5x volt-modded (R52 47k) 5-chip GridSeeds.
All together is powered with Platinum CORSAIR AX860. I don't want to burn my whole machine so what are FB23 & FB24 supposed to do and is there any risk to damage my PSU if i brick them.

Thank you in any advance!

Hmm that is interesting....I used this part from digikey for FB23/24 http://www.digikey.com/product-detail/en/742792121/732-4654-1-ND/4310394.  Mouser also had the part listed but it was backordered until mid August.

Unfortunately, I cannot verify that the part works because after making the repair, FB26 cracked and sizzled.  It was strange.  After the initial destruction of FB23/24 I could still hook up the usb port and have windows recognize the unit.  After the repair I only plugged in the 12v supply to test it...no sizzle so I thought I might be ok.  However when I plugged the usb cable into the unit(with 12 volt lead simultaneously), FB26, located near the usb port bit the dust.  I quickly unplugged before much damage was done...but there is clearly a crack in FB26 and some soot around the area.

What I cant explain is with the 12 volt plugged in, measuring voltage at the pins on the 12v jack, I get widely varying voltages from 0-12v.  So much so that the fan will only slightly move when the voltage spikes up to 12v and it wont even move a quarter of a turn.  It is possible that the 12v jack is bad or is there something else going on that I do not understand?

Anyone or maybe Wolfey have any ideas about what to try next?

Let us know how your repair goes Wors 

MOSFET(s) gone probably...

ZiG

[foz]

Even one of my volt-modded (R52 47k) 5-chip GridSeeds went dead after mining on 1200MHz.
You can see separated positive lead. I forgot to take picture while it seemed there is burned area 3x3cm.
I didn't have any ISO to clean so I used cheap Etheric Oil to clean the burned area  
After cleaning I was really happy that there are only FB23 & FB24 burned and that I am not the only one left with melted ferrite cores.
Short question if I order 74792121 part from Farnell will it work? What can potentially happen if I brick it

I am mining on my developing machine with R9 280x, HD5870 and 5x volt-modded (R52 47k) 5-chip GridSeeds.
All together is powered with Platinum CORSAIR AX860. I don't want to burn my whole machine so what are FB23 & FB24 supposed to do and is there any risk to damage my PSU if i brick them.

Thank you in any advance!

http://i61.tinypic.com/2zs17jo.jpg

Hmm that is interesting....I used this part from digikey for FB23/24 http://www.digikey.com/product-detail/en/742792121/732-4654-1-ND/4310394.  Mouser also had the part listed but it was backordered until mid August.

Unfortunately, I cannot verify that the part works because after making the repair, FB26 cracked and sizzled.  It was strange.  After the initial destruction of FB23/24 I could still hook up the usb port and have windows recognize the unit.  After the repair I only plugged in the 12v supply to test it...no sizzle so I thought I might be ok.  However when I plugged the usb cable into the unit(with 12 volt lead simultaneously), FB26, located near the usb port bit the dust.  I quickly unplugged before much damage was done...but there is clearly a crack in FB26 and some soot around the area.

What I cant explain is with the 12 volt plugged in, measuring voltage at the pins on the 12v jack, I get widely varying voltages from 0-12v.  So much so that the fan will only slightly move when the voltage spikes up to 12v and it wont even move a quarter of a turn.  It is possible that the 12v jack is bad or is there something else going on that I do not understand?

Anyone or maybe Wolfey have any ideas about what to try next?

Let us know how your repair goes Wors  

MOSFET(s) gone probably...

ZiG

Hi Zig...thanks for the helpful response.

I tested my mosfets with info from this thread GridSeed 5-chip USB miner voltage mod.  I believe one of them is shorted.  Have the part ordered... will update here when I get it replaced.

Thanks

[ZiG]

Even one of my volt-modded (R52 47k) 5-chip GridSeeds went dead after mining on 1200MHz.
You can see separated positive lead. I forgot to take picture while it seemed there is burned area 3x3cm.
I didn't have any ISO to clean so I used cheap Etheric Oil to clean the burned area 
After cleaning I was really happy that there are only FB23 & FB24 burned and that I am not the only one left with melted ferrite cores.
Short question if I order 74792121 part from Farnell will it work? What can potentially happen if I brick it

I am mining on my developing machine with R9 280x, HD5870 and 5x volt-modded (R52 47k) 5-chip GridSeeds.
All together is powered with Platinum CORSAIR AX860. I don't want to burn my whole machine so what are FB23 & FB24 supposed to do and is there any risk to damage my PSU if i brick them.

Thank you in any advance!

Hmm that is interesting....I used this part from digikey for FB23/24 http://www.digikey.com/product-detail/en/742792121/732-4654-1-ND/4310394.  Mouser also had the part listed but it was backordered until mid August.

Unfortunately, I cannot verify that the part works because after making the repair, FB26 cracked and sizzled.  It was strange.  After the initial destruction of FB23/24 I could still hook up the usb port and have windows recognize the unit.  After the repair I only plugged in the 12v supply to test it...no sizzle so I thought I might be ok.  However when I plugged the usb cable into the unit(with 12 volt lead simultaneously), FB26, located near the usb port bit the dust.  I quickly unplugged before much damage was done...but there is clearly a crack in FB26 and some soot around the area.

What I cant explain is with the 12 volt plugged in, measuring voltage at the pins on the 12v jack, I get widely varying voltages from 0-12v.  So much so that the fan will only slightly move when the voltage spikes up to 12v and it wont even move a quarter of a turn.  It is possible that the 12v jack is bad or is there something else going on that I do not understand?

Anyone or maybe Wolfey have any ideas about what to try next?

Let us know how your repair goes Wors 

MOSFET(s) gone probably...

ZiG

Hi Zig...thanks for the helpful response.

I tested my mosfets with info from this thread GridSeed 5-chip USB miner voltage mod.  I believe one of them is shorted.  Have the part ordered... will update here when I get it replaced.

Thanks

Glad to help, buddy...

Good luck...and keep us posted...

ZiG

[WorsAt5gPerDay]

Ok I got part from Farnell (FB 23&24). I am not sure it is the right one (FERRITE BEAD, 0.06OHM, 3A 1206) (742792121).
I resoldered red wire and two ferrite beads. Plugged the thing into the PC, fan spinned ok.

Then I replugged everything and started the PC... Waited 5 second, and the smoke come from another gridseed
Opened it and there was a hole in the MOSFET (I can see PCB under small 1x1mm hole), even that chip near R52 seems to be weird?

I retested every single one on standalone power supply and all works, even the one that smoke comes from. I plugged all back to PC and right now they are mining with no problem?!? Now for 1hour.

Lets go to real problem. Why my newly repaired GridSeed caused another one to blow FET? I am afraid to ever put that thing back into the PC. Right now it doesn't spin the fan anymore on standalone power supply.

EDIT: I just ordered three free samples (FETs) from TI (CSD17552Q5A ) and will replace FET on failing one. FBs were not enough.

[foz]

Ok I got part from Farnell (FB 23&24). I am not sure it is the right one (FERRITE BEAD, 0.06OHM, 3A 1206) (742792121).
I resoldered red wire and two ferrite beads. Plugged the thing into the PC, fan spinned ok.

Then I replugged everything and started the PC... Waited 5 second, and the smoke come from another gridseed
Opened it and there was a hole in the MOSFET (I can see PCB under small 1x1mm hole), even that chip near R52 seems to be weird?

I retested every single one on standalone power supply and all works, even the one that smoke comes from. I plugged all back to PC and right now they are mining with no problem?!? Now for 1hour.

Lets go to real problem. Why my newly repaired GridSeed caused another one to blow FET? I am afraid to ever put that thing back into the PC. Right now it doesn't spin the fan anymore on standalone power supply.

EDIT: I just ordered three free samples (FETs) from TI (CSD17552Q5A ) and will replace FET on failing one. FBs were not enough.

Hi wors

I am new to this also but that looks like the right part for FB 23/24.

I'll let some of the other more experienced members comment on your other questions. 

Hoping my mosfet will be here by the end of the week....hoping I can get the old one off without too much trouble also 

[wolfey2014]

Ok I got part from Farnell (FB 23&24). I am not sure it is the right one (FERRITE BEAD, 0.06OHM, 3A 1206) (742792121).
I resoldered red wire and two ferrite beads. Plugged the thing into the PC, fan spinned ok.

Then I replugged everything and started the PC... Waited 5 second, and the smoke come from another gridseed
Opened it and there was a hole in the MOSFET (I can see PCB under small 1x1mm hole), even that chip near R52 seems to be weird?

I retested every single one on standalone power supply and all works, even the one that smoke comes from. I plugged all back to PC and right now they are mining with no problem?!? Now for 1hour.

Lets go to real problem. Why my newly repaired GridSeed caused another one to blow FET? I am afraid to ever put that thing back into the PC. Right now it doesn't spin the fan anymore on standalone power supply.

EDIT: I just ordered three free samples (FETs) from TI (CSD17552Q5A ) and will replace FET on failing one. FBs were not enough.

What were you using to power them up? Perhaps the power supply caused the first FET to blow? If the power is dirty or unregulated or too high, this could happen.
The reason I ask is because when you run them on a separate power supply they don't FRY!
Check the power cords and connectors too.
If you have a DVM, check the voltage at all connectors.
The answer to your problem is in there somewhere. Just remember to keep it simple! The ol' KISS rule will set you free if you apply it and burn your ars if you don't
Good luck!
Wolfey2014

[WorsAt5gPerDay]

Thank you guys for help! This thread is so cool

Guess what. My GridSeed works after replacing FETs that come to EU for free faster than light!

Still now sure what caused FB23&24 to melt. After replacing them FET on another GridSeed burned a bit. I was thinking what happened, Wolfey said I should check connectors, good point cos they are home made and everyone is different But nah then I was thinking further, I wrote in later posts that I mine on my developing machine, that is ultra smart. After I replaced FBs GridSeed started to work again, and FET now caused new short on 12V and the closest GridSeed started to suffer. I am just happy that I shut down machine right time. Guys you should tell me that if one GridSeed pops short happens and this is bad. I have to immediately replace FET that is burned a bit, Gridseed is mining fine but it will blow some day! I should really run them on separate power supplies.

Now that I replaced FET I have mini problem. I downclocked to 1163MHz before starting and something wasn't ok. The reported speed was way over 500khash. I downclocked even more to 1100MHz but 470khash is to much. Is the new FET responsible for 10% gain? The only other thing could be three years old mining PSU that works on 11.5V   (i am on another testing machine now) ...
http://i60.tinypic.com/2mpwl08.png

Now that this works (I really hoped it won't so I could use heatsink for another home project ) I would like to revert my R52 mod. If I read thread right I just place two switches instead of bridges to revert to 36k resistor. Just one thing I would like to know can I dual mode if I do this? Dual Mining is more profitable ad I have free electricity so I would like to dual mine no just SHA256 or just Scrypt but dual mode.

 

[CartmanSPC]

I tried dual mining but found that while doing so gridseeds would start falling off slowly (zombie) requiring them to be power cycled. Since I have them running at a remote location and can not easily power cycle I changed back to just mining scrypt as that is solid.

[WorsAt5gPerDay]

I had similar problems before I modded them with 47.7k if I was mining in dual mode. They are just to unstable and if i have to watch it it will profit less. Maybe I will do the bridge mode with switch to use scrypt only (I want switch!) but I still don't know for sure if those bridges revert all to stock (ok 36k is little bigger than 33k) and it support dual mode for sure?

EDIT: Just bought AntMiner for SHA256 so I will leave GridSeeds on scrypt
foz, how is your repair?

[foz]

Heya wors

Glad ya got it sorted :-)

Finally got my mosfet replaced today.  I still need to replace FB26.. I cannot find the part in stock anywhere.  I wonder, can I use one of the FB 23/24 and temporarily replace the FB 26 with the 23/24 while I wait for the backorded part?  I realize doing this would be replacing the original part with one with double the current capacity.

Anyone have any comments or suggestions about doing this?

[ZiG]

I tried dual mining but found that while doing so gridseeds would start falling off slowly (zombie) requiring them to be power cycled. Since I have them running at a remote location and can not easily power cycle I changed back to just mining scrypt as that is solid.

The Gridseed can NOT run in BTC mode with VoltMod...even modest Vmod will rise the power consumption above the MOSFETs ability to handle...Capisco...

Just don't try BTC mode , when overvolt...You will blow MOSFETs ...or something else...at your risk...

BTC mode is fine only at stock voltage...

ZiG

[CartmanSPC]

Never said I did the VoltMod

...but yea, for those that do: Do NOT try to mine BTC

[foz]

Hmm that is interesting....I used this part from digikey for FB23/24 http://www.digikey.com/product-detail/en/742792121/732-4654-1-ND/4310394.  Mouser also had the part listed but it was backordered until mid August.

Unfortunately, I cannot verify that the part works because after making the repair, FB26 cracked and sizzled.  It was strange.  After the initial destruction of FB23/24 I could still hook up the usb port and have windows recognize the unit.  After the repair I only plugged in the 12v supply to test it...no sizzle so I thought I might be ok.  However when I plugged the usb cable into the unit(with 12 volt lead simultaneously), FB26, located near the usb port bit the dust.  I quickly unplugged before much damage was done...but there is clearly a crack in FB26 and some soot around the area.

What I cant explain is with the 12 volt plugged in, measuring voltage at the pins on the 12v jack, I get widely varying voltages from 0-12v.  So much so that the fan will only slightly move when the voltage spikes up to 12v and it wont even move a quarter of a turn.  It is possible that the 12v jack is bad or is there something else going on that I do not understand?

Update for my repair

Replacing the mosfet did not fix the issue.  With mosfet replaced I still had the same nonworking fan issue. I removed fb26 and have yet to get a replacement.  I did supply 12v through the jack in order to test with FB26 removed.  Wasn't for sure if that would cause an issue, but anyway the same mosfet blew again after about 40 seconds of 12v applied via the 12v jack.

I also visibly noticed some type of crystalline material oozing out of the p1707q IC located not far from FB 23/24, so I am assuming that is blown also.  The replacement for p1707q is here (http://www.adafruit.com/datasheets/MP2307_r1.9.pdf).  Have yet to order it.  Plus my FB26 wont ship till November.  Still might use a FB23 in place of FB26 temporarily.

http://i61.tinypic.com/29ctp3r.jpg

Any comments, suggestions or criticism welcome :-)

[toxic0n]

I've now had 5 out of 10 Gridseeds blow FB23&FB24 in the past 6 months. Replacing the beads just makes them blow again. Obviously the R52 volt mod was not a good idea, I'm guessing it's only a matter of time till the rest of them die.

[wolfey2014]

I've now had 5 out of 10 Gridseeds blow FB23&FB24 in the past 6 months. Replacing the beads just makes them blow again. Obviously the R52 volt mod was not a good idea, I'm guessing it's only a matter of time till the rest of them die.

Sounds like a few of a bad batch of miners that got through QC - of which is known to be fairly poor to piss poor anyway - are rearing their ugly little heads.
I've had 25 personally modified pods running for months and months with no issues!
Also, things tend to just work right when I'm around anyway

Happy Holidays Folks!
Wolfey2014

Pea Essssssssssssss, they've all paid for themselves a few times over by now too! One of the lucky ones I am

[toxic0n]

You are lucky, that is true.
Latest failure, looks like both FBs got blown off cleanly 

[CartmanSPC]

My un-moded units have been extremely stable