Topic: buying second hand miner (Read 2458 times)

Wow You are one to call some one shady.    Talk about the Pot calling the Kettle Black. 

I suggest calling Bitmain.  I think they fed you a line when they said "called their representative at Bitmain".   This site is not an official reseller.

Read the warranty from Bitmain - https://bitmain.zendesk.com/hc/en-us/articles/202661989-Limited-90-Day-Warranty-Terms-  It is only good for the original owner.  In this case 2ndHandMiner.com once they sold it to you there was no warranty unless Bitmain was feeling nice and made an exception.   

Order from Bitmain so it's official if your getting new gear. (Or 2nd hand official on Bitmain currently).   Used gear yes you can get other places but don't expect warranty.

If you ordered with credit card and they truly sold you a S5 where only 1 hashing board works, might call credit card company up and see about dispute.

Before you do that though try to problem solve.  What PSU did you use with your S5?

What ever you do don't buy used miner from 2ndHandMiner.com

This is the shadiest site ever. I want to warn and recommend everyone not to buy any hardware from Amy K Brannan and their website.  I purchased an S5 Antminer and it arrived with only one hashing board working.  I tried to work with Amy to get the issue resolved and my return request was declined, also I was told that they called their representative at Bitmain Tech and told them not to honor any warranty repair for my item.  Also they have a tendency to jack up the price on a product once you add it to your cart. So if it's like 499 and you add to cart to check out all of sudden it's now 599. They are super shady and not customer service friendly at all.  It takes them at least a week or two to respond to any issues you may have. Don't trust these guys and don't order from them they won't make it right and they will send you malfunctioning equipment.

@ op did you get the s4's or did you pass on the deal?

As I said I was pushing them hard on intensity.  I did not work with amazon I worked with manufactures with RMA.  On GPU's the companies had a surprisingly long RMA period.

I parted all my rigs out a while back.  Just was not enough profit in it.  I would be suprised if you can run a GPU rig with extra cooling during summer and have a chance at ROI for what you paid on GPU.

Mine was back when 3 month ROI was common place. Heck GPU's were even sold out on a lot of the common mining models back then.

never had any problem with my gpu rig, and i also had quite a bit of different vga for mining, the occasional rma is not a problem either, you can resolve it fast with amazon

he can add some big fan of 200-400mm to keep his miners cool, but in summer i would go with downclocking the frequency

I think it depends on amount.  I don't think his living situation will allow to much of abuse of power.  I just don't think it's going to have a ton of circuit breakers ran to it. 

But you are right it could go from learning to abuse at a point.   And if you are in military I would not want to explain what a bitcoin miner is if they ever do check rooms, they might just see it as a unauthorized device.   So read your housing contract close.

Even if using military with free their gonna start asking questions if they see a spike in his energy use. But still if its free then I would be looking at all the other factors tho. Brake even point on equipment bought and from reading more comments in post and comparing heat to computers running is a lot more heat. After seeing price is going to pay is goin to be a waste. I would just buy BTC and wait for that to increase than to put bigger risk into equipment. Also if mining and going to stick units into closet that is going to heat the units up even more so due to the fact on 24/7 and no air flow to them more than likely over heat them and burn up.
Each unit will run around 30c to 40c depending on ambien temp, better you can get that the units will be cooler running.

Thank you for pointing out nothing as fun as drinking must have been tired.   Yes they did a great job of cooling down multiple rooms during winter.

Summer I have been fighting heat with fan's.  Happy to be mining but sure is not cooling down the areas I mine in.

That last sentence is very, very confusing! Miners cool down a room in summer?! And you need cooling in the winter?! Have you been drinking? Lol.

Glad to help.  I hope it works out great for you, I always welcome new miners .

And during summer winter they really do a great job of cooling down a room.   I saved quite a bit last winter on cooling.

On the bright side during winter I can shut my window and have a warm room for the first time in my career haha. Yeh I'll have another look at my ROI but if it take 12+ months just to get back what I paid oh well, where's the fun without the risk? Closet of death that made me chuckle notlist3d. Thanks again

Not a problem at all. I would do some ROI math though before buying still take into account only turned on for X hours per day.

A exhaust out window should work fine.  Lots better then the closet of death .

thanks for all the replies I really underestimated how much heat these things kick out it seems, so ill re-think how I set it up, worst case I can leave it next to the window while im at work and if needs be power down so I can sleep lol.

With a gaming rig you are not putting it on crazy intensity.   I did lot's of GPU mining a while back you push those cards very very hard.  It was not uncommon to have to RMA as you pushed it to far.

With gaming the cards are just not pushed near as hard.  RMA proves this with much much lower rate of cards dying.


I hope he is able to mine but hes going to need somewhere else besides a closet.  Although I truly wish you could throw them in closet would be so much easier.

well it depend, if i put a gaming rig with 2-3 x 295x it's like having one s4 basically, not much of a difference, also 3 vga will generate a heat that would be above the one of a single s4

i don't remember right now, but s4 can't sustain a temp of 90+ degree..

The amount of heat from multiple S4's most likely would destory them if you put them in a closet with no airflow, or exhust.

I think the "free" housing you have most likely will not be good for holding gear.  Unless you have more then just a bedroom to yourself.

You sure put a lot of effort into your post. But I guess you missed the part where he said he's in military housing with free electricity. 

You can't compare a gaming rig's heat generation to two S4's... not even close. Each S4 is probably equivalent to two hair dryers running at full blast. Now imagine that running in your room or closet 24 hours a day.

id be looking at energy costs first before buying any equipment cheap or not. All comes down to energy use. If you getting a bunch of s4s get the total energy it is going to consume including your pc and monitor too. Next once you got total KW in use then workout 24/7 use and take this to your energy unit and work out your total cost that it is going to cost. To give you an idea where my bills are or where at when mining  using 3200 Watts per day was racking me up almost £9.00 per day including VAT on top and other bits took me very close to getting into £10 per day for close to 4KW of energy used. Then factoring cooling fans that I had running in summer took me above £10 at on point per day in energy used. I ended up under clocking some units and under-volt that did save me about 20 to 30% but after prices sky rocketed down and massive spikes in difficulty it was not working out when seeing that energy was out weighing earnings even to save the BTC for future, it was better to just buy the bitcoin and hold it.

Only way to succeed in mining right now is if you got 1PH of hash power, free energy, cheap equipment, or you have a business that you can run and use the energy in it claim taxes back in energy used and also make a tax wright off. I have thought about making own mining company a number of times and each time succeeded in making a fail safe plan until bigger units come on wipe out the hash rate and also move things up in difficulty. Each time diff goes up every 2 weeks your going to find a cut anywhere between 2 to 10% or 10 to 15% or even more on loss of generation unless you can continue to off set it and each time you are compensating for the diff changes and can keep in the race of it or it is simply buy a bunch of equipment and take the risk of losing or not making RIO.

Best advise Sit back and work everything out and factor everything in before mining. I would personally but the coins sit back on them spread across alt coins and enjoy the profit form the rises in coin value than making bigger risk on mining unless it is going to be wroth while.