Thanks
As you say: Door stop, book end, paper weight and boat anchor.

I found https://rpiplayground.wordpress.com/ with a google search.

Like you, I wondered if there was any other use for the Antminer U series - cracking passwords perhaps - but it seems not.

When you discover what will remove the glue, let us know.

I'd try d-limonene to start with, then methylene dichloride then MEK.

My criticism of this device from Bitmain is that the cost is such that it can never be recouped.  This is a coffee table device, a conversation piece, a piece of art, but it will never make the purchaser money.

If Bitmain really wants to support the home miner, the design has to be drastically simplified so that people can make a working miner with parts from their junk box.
To wit, no power supply should be included plus the purchaser provides a heat sink and cooling.  It should be a barebones device which can run from a range of voltages (12V from an old ATX power supply or 18.5V from a laptop brick - in other words whatever is to hand), it should be available with an order quantity of one and the price should be such that no VAT or duty is payable.  Delivery should be low cost.

I don't know what the market for such a device would be, but considering that the Raspberry Pi has sold 3 million, there is evidently considerable demand for products for hackers.

Another thing that's wrong with these devices is that they should be able to be run from a laptop power supply brick - so 12-20V input or 12 x root(2) V (12v lighting transformer)

This is designed as a coffee table conversation piece - it's certainly not for hackers.

I'm perfectly aware that it is not a DIY device.
You're helping to market a device that will never make a cent for the purchasers.
I was asking no such thing.  I just remarked upon how it is that I've never paid VAT or duty on items from China.

I'm complaining that a DIY device is not being marketed and that the order quantity is ridiculous.  There would be no power supply included and it would be up to the recipient to bolt on a heatsink and cooling.  I've got plenty of heatsinks and cooling fans from defunct processors.  With the cost of VAT and duty and the mark up of middle men, these are being marketed to the naive.  How is that for ethical company behaviour ?

Additionally I pay all the taxes that I'm asked to pay so I resent your allegation that I'm not.

There is customs duty to add as well surely.

VAT is to do with Bitmain.  Below a certain price, no VAT or Duty is payable.

I buy lots of stuff from China and never pay any duty or VAT because I keep the cost and weight below certain amounts and perhaps because the vendors lie about the price I paid. Of course this is not possible with a minimum order quantity of 20.  Perhaps Bitmain should team up with some of the vendors in Shenzhen that one can find on aliexpress.com

As a home miner, I don't want to pay duty on the controller when I can buy a Raspberry Pi and use cgminer.
Also, I don't want to scrap the controller (as well) when it is no longer financially viable to operate the kit.

Please make a device like this (or air cooled) which can be powered by 1 ATX PSU and which has a USB connection - so I have a logical upgrade path from Antminer U2.

Perhaps such a device could also make use of the airflow from the ATX PSU.

Better still if you could sell a unit that came in less than the threshold for duty payments.

Otherwise, it's great to see you innovating.

When will Bitmain launch a successor to the U2 ?

Hobbyists have deployed these, but now they have diminishing returns.

May I suggest a device with a USB interface and heat sink that appears like one or more U2s and that can be used with, for example, cgminer.

The user would need to supply forced cooling, a 12V supply and a controller (Raspberry Pi B+ perhaps).

I suggest a hash rate of 100GHs^-1 - that is 1/4 S3

Doing this would have a number of benefits for the customer:
a) a lower entry cost
b) reduced customs charges
c) less equipment to scrap when the device is no longer cost effective.

Bitmain would benefit from more sales.

You could implement SPI in software and allocate a different GPIO pin for each chip select.  Doing SPI in software isn't difficult per se.