[GUIDE] Undervolt antminer s1 [1.19W/GH at the wall]

[Trends]

I have never done anything like this, so a few questions from a newb:
1. My understanding that for undervolting as per bitmain scheme, I will be removing R3, etc. resistors, but then instructions are a bit thin for me…Do I put something else in place? bitmain says: refer to resistor value to replace. This is where I don't understand. I have to replace R3 and 7 other resistors (8 total, 4 on each board) with what?
2. how POTs came into this? Is it a POT I have to put in place of removed resistors, or is it optional and I can simply put a small droplet of tin where resistor (R3, etc) was?

Thanks
[/quote]

Yes remove the R3, R66, R38 & R52 resistors from each blade. Either replace these removed resistors with new resistors of the value Bitmain has given (3.24Kohm for 102.4Ghash or 4.02Kohm for 115.2Ghash).
Alternatively instead of putting in the fixed value resistors (3.24 or 4.02) put in a 0 to 10Kohm adjustable resistors (POT) (this is what is shown on the pictures attached a page or two back). With the POTs you can undervolt, go back to stock, or if you are brave overvolt with no more hardware changes!

Trends

[Brassguy]

Trends.. I think I understand what you are saying.... When I measure the R3, etc resistor on my ant I see a value of 4.47K... duh.. it's in circuit... I'm yet again a dumbass.

[klondike_bar]

I have never done anything like this, so a few questions from a newb:
1. My understanding that for undervolting as per bitmain scheme, I will be removing R3, etc. resistors, but then instructions are a bit thin for me…Do I put something else in place? bitmain says: refer to resistor value to replace. This is where I don't understand. I have to replace R3 and 7 other resistors (8 total, 4 on each board) with what?
2. how POTs came into this? Is it a POT I have to put in place of removed resistors, or is it optional and I can simply put a small droplet of tin where resistor (R3, etc) was?

Thanks

Yes remove the R3, R66, R38 & R52 resistors from each blade. Either replace these removed resistors with new resistors of the value Bitmain has given (3.24Kohm for 102.4Ghash or 4.02Kohm for 115.2Ghash).
Alternatively instead of putting in the fixed value resistors (3.24 or 4.02) put in a 0 to 10Kohm adjustable resistors (POT) (this is what is shown on the pictures attached a page or two back). With the POTs you can undervolt, go back to stock, or if you are brave overvolt with no more hardware changes!

Trends

just do a pencil mod. its easy enough that anyone can do it.  All you need is a pencil and a multimeter, and about 10-15 minutes per antminer.  (a 4B pencil is a bit easier to work with than a 2B/HB since its softer lead).  Its not as precise a method as actually soldering a new resistor, but its ~95% as effective and far faster and less likely to do permentant amage then using a soldering iron to remove/replace a SMALL resistor

[philipma1957]

If you ever wanted to get back to "stock 180GH" your pot would have to go up to 8.2Kohms which puts you at 1.12 -1.13 V at the chip.
5K ohm will only get you up to 0.9 to 0.92 V at the chip.
0- 10K are just as common as 0-5K and both are priced the same at $0.40 - $0.70ea
If you're going to play, play right.

my oem resistors were all 4.46k

     so a 5k pot should work

[Brassguy]

If you ever wanted to get back to "stock 180GH" your pot would have to go up to 8.2Kohms which puts you at 1.12 -1.13 V at the chip.
5K ohm will only get you up to 0.9 to 0.92 V at the chip.
0- 10K are just as common as 0-5K and both are priced the same at $0.40 - $0.70ea
If you're going to play, play right.

my oem resistors were all 4.46k

     so a 5k pot should work

I'm thinking that they measure ~4.47K in circuit... but that may be a false reading without measuring the resistor out of the circuit. I'll find out when my pots come in... I have both 5K and 10K coming

[Trends]

If you ever wanted to get back to "stock 180GH" your pot would have to go up to 8.2Kohms which puts you at 1.12 -1.13 V at the chip.
5K ohm will only get you up to 0.9 to 0.92 V at the chip.
0- 10K are just as common as 0-5K and both are priced the same at $0.40 - $0.70ea
If you're going to play, play right.

my oem resistors were all 4.46k

     so a 5k pot should work

I'm afraid you are wrong, you must be measuring on the board in circuit.

[Trends]

I have never done anything like this, so a few questions from a newb:
1. My understanding that for undervolting as per bitmain scheme, I will be removing R3, etc. resistors, but then instructions are a bit thin for me…Do I put something else in place? bitmain says: refer to resistor value to replace. This is where I don't understand. I have to replace R3 and 7 other resistors (8 total, 4 on each board) with what?
2. how POTs came into this? Is it a POT I have to put in place of removed resistors, or is it optional and I can simply put a small droplet of tin where resistor (R3, etc) was?

Thanks

Yes remove the R3, R66, R38 & R52 resistors from each blade. Either replace these removed resistors with new resistors of the value Bitmain has given (3.24Kohm for 102.4Ghash or 4.02Kohm for 115.2Ghash).
Alternatively instead of putting in the fixed value resistors (3.24 or 4.02) put in a 0 to 10Kohm adjustable resistors (POT) (this is what is shown on the pictures attached a page or two back). With the POTs you can undervolt, go back to stock, or if you are brave overvolt with no more hardware changes!

Trends

just do a pencil mod. its easy enough that anyone can do it.  All you need is a pencil and a multimeter, and about 10-15 minutes per antminer.  (a 4B pencil is a bit easier to work with than a 2B/HB since its softer lead).  Its not as precise a method as actually soldering a new resistor, but its ~95% as effective and far faster and less likely to do permentant amage then using a soldering iron to remove/replace a SMALL resistor

Agreed, but not as much fun!!

[Biodom]

I have never done anything like this, so a few questions from a newb:
1. My understanding that for undervolting as per bitmain scheme, I will be removing R3, etc. resistors, but then instructions are a bit thin for me…Do I put something else in place? bitmain says: refer to resistor value to replace. This is where I don't understand. I have to replace R3 and 7 other resistors (8 total, 4 on each board) with what?
2. how POTs came into this? Is it a POT I have to put in place of removed resistors, or is it optional and I can simply put a small droplet of tin where resistor (R3, etc) was?

Thanks

Yes remove the R3, R66, R38 & R52 resistors from each blade. Either replace these removed resistors with new resistors of the value Bitmain has given (3.24Kohm for 102.4Ghash or 4.02Kohm for 115.2Ghash).
Alternatively instead of putting in the fixed value resistors (3.24 or 4.02) put in a 0 to 10Kohm adjustable resistors (POT) (this is what is shown on the pictures attached a page or two back). With the POTs you can undervolt, go back to stock, or if you are brave overvolt with no more hardware changes!

Trends

just do a pencil mod. its easy enough that anyone can do it.  All you need is a pencil and a multimeter, and about 10-15 minutes per antminer.  (a 4B pencil is a bit easier to work with than a 2B/HB since its softer lead).  Its not as precise a method as actually soldering a new resistor, but its ~95% as effective and far faster and less likely to do permentant amage then using a soldering iron to remove/replace a SMALL resistor

Is pencil mod even stable or you have to constantly monitor the ant's power usage/HW mistakes and re-mod every week or two?

[philipma1957]

I have never done anything like this, so a few questions from a newb:
1. My understanding that for undervolting as per bitmain scheme, I will be removing R3, etc. resistors, but then instructions are a bit thin for me…Do I put something else in place? bitmain says: refer to resistor value to replace. This is where I don't understand. I have to replace R3 and 7 other resistors (8 total, 4 on each board) with what?
2. how POTs came into this? Is it a POT I have to put in place of removed resistors, or is it optional and I can simply put a small droplet of tin where resistor (R3, etc) was?

Thanks

Yes remove the R3, R66, R38 & R52 resistors from each blade. Either replace these removed resistors with new resistors of the value Bitmain has given (3.24Kohm for 102.4Ghash or 4.02Kohm for 115.2Ghash).
Alternatively instead of putting in the fixed value resistors (3.24 or 4.02) put in a 0 to 10Kohm adjustable resistors (POT) (this is what is shown on the pictures attached a page or two back). With the POTs you can undervolt, go back to stock, or if you are brave overvolt with no more hardware changes!

Trends

just do a pencil mod. its easy enough that anyone can do it.  All you need is a pencil and a multimeter, and about 10-15 minutes per antminer.  (a 4B pencil is a bit easier to work with than a 2B/HB since its softer lead).  Its not as precise a method as actually soldering a new resistor, but its ~95% as effective and far faster and less likely to do permentant amage then using a soldering iron to remove/replace a SMALL resistor

Is pencil mod even stable or you have to constantly monitor the ant's power usage/HW mistakes and re-mod every week or two?

my pencil mod is 11 days old 3 ants do 430gh at 563 watts.

  rock solid for 11 days.

[Biodom]

Yes remove the R3, R66, R38 & R52 resistors from each blade. Either replace these removed resistors with new resistors of the value Bitmain has given (3.24Kohm for 102.4Ghash or 4.02Kohm for 115.2Ghash).
Alternatively instead of putting in the fixed value resistors (3.24 or 4.02) put in a 0 to 10Kohm adjustable resistors (POT) (this is what is shown on the pictures attached a page or two back). With the POTs you can undervolt, go back to stock, or if you are brave overvolt with no more hardware changes!

Trends

Where do you buy these POTs? thanks

[philipma1957]

I have never done anything like this, so a few questions from a newb:
1. My understanding that for undervolting as per bitmain scheme, I will be removing R3, etc. resistors, but then instructions are a bit thin for me…Do I put something else in place? bitmain says: refer to resistor value to replace. This is where I don't understand. I have to replace R3 and 7 other resistors (8 total, 4 on each board) with what?
2. how POTs came into this? Is it a POT I have to put in place of removed resistors, or is it optional and I can simply put a small droplet of tin where resistor (R3, etc) was?

Thanks

Yes remove the R3, R66, R38 & R52 resistors from each blade. Either replace these removed resistors with new resistors of the value Bitmain has given (3.24Kohm for 102.4Ghash or 4.02Kohm for 115.2Ghash).
Alternatively instead of putting in the fixed value resistors (3.24 or 4.02) put in a 0 to 10Kohm adjustable resistors (POT) (this is what is shown on the pictures attached a page or two back). With the POTs you can undervolt, go back to stock, or if you are brave overvolt with no more hardware changes!

Trends

Where do you buy these POTs? thanks
[/quote]


mouser/newark/jameco  a few others.    Since I may be wrong about the 5k  the 10k pot may be better   here is a  link for a low cost 10k pot

http://www.mouser.com/ProductDetail/Bourns/3306F-1-103/?qs=sGAEpiMZZMtC25l1F4XBU9QhtPcWQTANAkX0QUL%2f5Dw%3d


please check with others but I think this is good.

[uberdag]

Do we not need to get certain wattage rating for the resistors as well as ohm?

[philipma1957]

Do we not need to get certain wattage rating for the resistors as well as ohm?

yes we do.  but the oem resistor was  4.47k in circuit and i think 8.3 k pulled    if so it had a low watt rating due to its size.  


these are close to the size and quality of the stock resistor they don't handle much power.

http://www.ebay.com/itm/8-2K-OHM-SMD-1206-Resistor-5000PCS-One-Roll-New-RoHS-/200999285608?pt=LH_DefaultDomain_0&hash=item2ecc7db368

items that small simply can  not handle much in terms of watts.

on the ebay link the most any of those resistors need handle = 1/4 watt

the ones on the antminer are most likely 1/4 watt or less.

 I am not the best authority   wait for more confirmation on the correct pot to use

[uberdag]

figure they are low but sure dont wannt get the wrong ones... blew a monitor i was working on when i forgot that resisters in series need to add the wattage up... well didnt so much blow it up as melt some things

[grn]

I have never done anything like this, so a few questions from a newb:
1. My understanding that for undervolting as per bitmain scheme, I will be removing R3, etc. resistors, but then instructions are a bit thin for me…Do I put something else in place? bitmain says: refer to resistor value to replace. This is where I don't understand. I have to replace R3 and 7 other resistors (8 total, 4 on each board) with what?
2. how POTs came into this? Is it a POT I have to put in place of removed resistors, or is it optional and I can simply put a small droplet of tin where resistor (R3, etc) was?

Thanks

Yes remove the R3, R66, R38 & R52 resistors from each blade. Either replace these removed resistors with new resistors of the value Bitmain has given (3.24Kohm for 102.4Ghash or 4.02Kohm for 115.2Ghash).
Alternatively instead of putting in the fixed value resistors (3.24 or 4.02) put in a 0 to 10Kohm adjustable resistors (POT) (this is what is shown on the pictures attached a page or two back). With the POTs you can undervolt, go back to stock, or if you are brave overvolt with no more hardware changes!

Trends

just do a pencil mod. its easy enough that anyone can do it.  All you need is a pencil and a multimeter, and about 10-15 minutes per antminer.  (a 4B pencil is a bit easier to work with than a 2B/HB since its softer lead).  Its not as precise a method as actually soldering a new resistor, but its ~95% as effective and far faster and less likely to do permentant amage then using a soldering iron to remove/replace a SMALL resistor

Is pencil mod even stable or you have to constantly monitor the ant's power usage/HW mistakes and re-mod every week or two?

my pencil mod is 11 days old 3 ants do 430gh at 563 watts.

  rock solid for 11 days.

Pencil mod has been working great for me

[klondike_bar]

I have never done anything like this, so a few questions from a newb:
1. My understanding that for undervolting as per bitmain scheme, I will be removing R3, etc. resistors, but then instructions are a bit thin for me…Do I put something else in place? bitmain says: refer to resistor value to replace. This is where I don't understand. I have to replace R3 and 7 other resistors (8 total, 4 on each board) with what?
2. how POTs came into this? Is it a POT I have to put in place of removed resistors, or is it optional and I can simply put a small droplet of tin where resistor (R3, etc) was?

Thanks

Yes remove the R3, R66, R38 & R52 resistors from each blade. Either replace these removed resistors with new resistors of the value Bitmain has given (3.24Kohm for 102.4Ghash or 4.02Kohm for 115.2Ghash).
Alternatively instead of putting in the fixed value resistors (3.24 or 4.02) put in a 0 to 10Kohm adjustable resistors (POT) (this is what is shown on the pictures attached a page or two back). With the POTs you can undervolt, go back to stock, or if you are brave overvolt with no more hardware changes!

Trends

just do a pencil mod. its easy enough that anyone can do it.  All you need is a pencil and a multimeter, and about 10-15 minutes per antminer.  (a 4B pencil is a bit easier to work with than a 2B/HB since its softer lead).  Its not as precise a method as actually soldering a new resistor, but its ~95% as effective and far faster and less likely to do permentant amage then using a soldering iron to remove/replace a SMALL resistor

Is pencil mod even stable or you have to constantly monitor the ant's power usage/HW mistakes and re-mod every week or two?

pencil mod is very stable. just remember that over the first day or two of operation the graphite is baked with heat and oxidized, and becomes *slightly* less resitive, lowering unit voltage so that clockspeed might need to tune down ~12MHz after 24hrs to remain stable. 90% of the time you wont notice unless you were finely tuning the clock to start with.

i would not suggest the actual resitor swapping with an iron to anyone but a pro - if you are not sure if you can do it with the tools you have - theres a huge chance youll end up desoldering nearby components and going in to a proper repair shop monday so a pro can fix your mistakes / burn marks. I personally like tinkering with solder as much as the next guy, but these itty-bitty SMD resistors require a lot of precision

[Trends]

I agree 100% with klondike_bar, if your'e not sure don't try this mod, use the pencil method.



 grn

looks like you have found every block in the last 5 days based on your Ant Monitor unless the block column means something else! 

[Biodom]

I have never done anything like this, so a few questions from a newb:
1. My understanding that for undervolting as per bitmain scheme, I will be removing R3, etc. resistors, but then instructions are a bit thin for me…Do I put something else in place? bitmain says: refer to resistor value to replace. This is where I don't understand. I have to replace R3 and 7 other resistors (8 total, 4 on each board) with what?
2. how POTs came into this? Is it a POT I have to put in place of removed resistors, or is it optional and I can simply put a small droplet of tin where resistor (R3, etc) was?

Thanks

Yes remove the R3, R66, R38 & R52 resistors from each blade. Either replace these removed resistors with new resistors of the value Bitmain has given (3.24Kohm for 102.4Ghash or 4.02Kohm for 115.2Ghash).
Alternatively instead of putting in the fixed value resistors (3.24 or 4.02) put in a 0 to 10Kohm adjustable resistors (POT) (this is what is shown on the pictures attached a page or two back). With the POTs you can undervolt, go back to stock, or if you are brave overvolt with no more hardware changes!

Trends

just do a pencil mod. its easy enough that anyone can do it.  All you need is a pencil and a multimeter, and about 10-15 minutes per antminer.  (a 4B pencil is a bit easier to work with than a 2B/HB since its softer lead).  Its not as precise a method as actually soldering a new resistor, but its ~95% as effective and far faster and less likely to do permentant amage then using a soldering iron to remove/replace a SMALL resistor

Is pencil mod even stable or you have to constantly monitor the ant's power usage/HW mistakes and re-mod every week or two?

my pencil mod is 11 days old 3 ants do 430gh at 563 watts.

  rock solid for 11 days.

Pencil mod has been working great for me

Ok, thanks, I think I got it. Will try pencil first. The R3 and other resistors are so tiny, I will mess them up with the iron for sure.

[philipma1957]

I have never done anything like this, so a few questions from a newb:
1. My understanding that for undervolting as per bitmain scheme, I will be removing R3, etc. resistors, but then instructions are a bit thin for me…Do I put something else in place? bitmain says: refer to resistor value to replace. This is where I don't understand. I have to replace R3 and 7 other resistors (8 total, 4 on each board) with what?
2. how POTs came into this? Is it a POT I have to put in place of removed resistors, or is it optional and I can simply put a small droplet of tin where resistor (R3, etc) was?

Thanks

Yes remove the R3, R66, R38 & R52 resistors from each blade. Either replace these removed resistors with new resistors of the value Bitmain has given (3.24Kohm for 102.4Ghash or 4.02Kohm for 115.2Ghash).
Alternatively instead of putting in the fixed value resistors (3.24 or 4.02) put in a 0 to 10Kohm adjustable resistors (POT) (this is what is shown on the pictures attached a page or two back). With the POTs you can undervolt, go back to stock, or if you are brave overvolt with no more hardware changes!

Trends

just do a pencil mod. its easy enough that anyone can do it.  All you need is a pencil and a multimeter, and about 10-15 minutes per antminer.  (a 4B pencil is a bit easier to work with than a 2B/HB since its softer lead).  Its not as precise a method as actually soldering a new resistor, but its ~95% as effective and far faster and less likely to do permentant amage then using a soldering iron to remove/replace a SMALL resistor

Is pencil mod even stable or you have to constantly monitor the ant's power usage/HW mistakes and re-mod every week or two?

my pencil mod is 11 days old 3 ants do 430gh at 563 watts.

  rock solid for 11 days.

Pencil mod has been working great for me

Ok, thanks, I think I got it. Will try pencil first. The R3 and other resistors are so tiny, I will mess them up with the iron for sure.

yeah smd resistors are hard to do.  I am 57, but  my eyes are older I have had cataract surgery in each one.

I can see far  in one I can see medium in the other,   but close meh so so at best.

[grn]

I agree 100% with klondike_bar, if your'e not sure don't try this mod, use the pencil method.



 grn

looks like you have found every block in the last 5 days based on your Ant Monitor unless the block column means something else! 

yes the block column is correct

all my ants are load balanced I solo mine with 1 of them plus I mine alt coins when profitable.