Hi Stefan,

  Thank you for the clarification.

I bought one of these:
http://www.ebay.com/itm/1158312-1-8V-ADAPTER-FOR-IPHONE-OR-MOTHERBOARD-SPI-FLASH-SOP8-DIP8-W25-MX25-USE/253102266601?ssPageName=STRK%3AMEBIDX%3AIT&_trksid=p2057872.m2749.l2649

Which is based on an AMS1117 regulator, coupled with a 

ALVC164245 16-bit dual supply translating transceiver


During the weekend, my new chips arrived, so I tried again, with the original setup: 

CH341a programmer -> 1.8V adapter -> test clip with original ribbon cable clipped to one of the new chips.

  The flash procedure worked and verified flawlessly, so there is either some interference from trying to flash the chip on board, or the original chip is damaged.

I'm sending the flashed chips to someone with better sioldering skills than me.

Best regards

Marius
On Monday, October 2, 2017 00:43 CEST, Stefan Tauner <stefan.tauner@gmx.at> wrote:
 
On Fri, 22 Sep 2017 12:36:44 +0200
"Marius Schrecker" <marius.schrecker@lyse.net> wrote:

> I get (randomly):
> Found Winbond flash chip "unknown Winbond (ex Nexcom) SPI chip" (0 kB, SPI) on ch341a_spi.
> Found Generic flash chip "unknown SPI chip (RDID)" (0 kB, SPI) on ch341a_spi.
> Found Winbond flash chip "W25Q64.W" (8192 kB, SPI) on ch341a_spi.
>
> Finding the correct chip or not seems to have little or nothing to do with the physical contact to the chip.
> […]
> Again, the hex codes for the failures seem pretty random and are different each time I try the command.

Hi Marius,

it is indeed random, because you apparently pick up lots of noise.
Please see https://flashrom.org/Common_problems and
https://www.flashrom.org/ISP
Which voltage translator/adapter are you using?

--
Kind regards/Mit freundlichen Grüßen, Stefan Tauner