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Products => Test Equipment => Topic started by: kyle on October 23, 2017, 03:36:53 am

Title: Test Clip for 8 contact VDFN flash memory chip?
Post by: kyle on October 23, 2017, 03:36:53 am
Hello,

Can somebody help me out finding clips/grabbers that would work with a "8 contact VDFN" package chip?

(https://i.imgur.com/ibyqVz6.jpg)

http://www.bdtic.com/datasheet/EON/EN25QH128.pdf (http://www.bdtic.com/datasheet/EON/EN25QH128.pdf)

The flash chip is located on my Thinkpad T430s laptop that I'm trying to reflash stock UEFI firmware via SPI with 100% open source Coreboot firmware https://www.coreboot.org/. (https://www.coreboot.org/.) The pitch appears to be ~1.2mm or so (measured with crappy ruler and my eyes). I know that Pomona 5250 Test Clip is very popular but that's for SOIC. Would it work with my VDFN?

Thanks in advance.
Title: Re: Test Clip for 8 contact VDFN flash memory chip?
Post by: ElektroQuark on October 23, 2017, 07:16:49 am
For a "one time job" you could solder some wires directly to the solder pads. Somewhat tricky but it will work.
Title: Re: Test Clip for 8 contact VDFN flash memory chip?
Post by: voltlog on October 23, 2017, 07:36:35 am
It would be next to impossible to fit one of those clips in there due to surrounding passives. The memory chip and it's pads are very close to the board and you will not be able to bring the contacts that close to the board. Soldering some wires would be the best idea in this case. You don't necesarly need to solder on the chip itself, you might find those signals on nearby test pads and/or pull-up resistors. Good luck!
Title: Re: Test Clip for 8 contact VDFN flash memory chip?
Post by: mikeselectricstuff on October 23, 2017, 07:50:27 am
It's only 8 pins - solder some wires on.
if you want something more robust, glue a piece of protoboard to the top of the chip with a connector on it, and wire down to the pins
Title: Re: Test Clip for 8 contact VDFN flash memory chip?
Post by: texaspyro on October 23, 2017, 05:08:28 pm
I used a SOIC-8 clip on a similar package.  I cut off all the plastic surrounding the pins.  It was rather wonky to use, but it worked.
Title: Re: Test Clip for 8 contact VDFN flash memory chip?
Post by: kyle on October 24, 2017, 10:28:24 pm
Thank you for all the suggestions. I ended up soldering smallest wires I could find and using sharpest bit on the soldering iron, and then I put some hot glue on them to keep them from falling off. It was extremely hard to solder them, this picture isn't doing justice, in real life there's barely any room to work with, but I got it!

(https://a.pomf.cat/ktfzrm.jpg)

I finally dumped the 16MB ROM off the flash chip, I used piratebus 3.6 with very old firmware (as I didn't have my beagleboard nor raspi prepared for SPI reading).
Code: [Select]
flashrom -p buspirate_spi:dev=/dev/ttyUSB0 -r t430s_stock.bin

It took piratebus 50 minutes. It seems like flashrom can control piratebus on its own, it's pretty cool, all I had to worry about is wiring. Now at the very moment I'm dumping the flash chip again and will compare the hashes.
Title: Re: Test Clip for 8 contact VDFN flash memory chip?
Post by: ebclr on October 25, 2017, 02:11:22 am
May this one will be help

Check the link


https://pt.aliexpress.com/item/TSSOP-MSOP-car-remote-control-key-chip-pin-SMD-DIP-chipIC-clip-clip-burn-folder/32535219524.html?spm=a2g0s.9042311.0.0.by4JMI
Title: Re: Test Clip for 8 contact VDFN flash memory chip?
Post by: kyle on October 25, 2017, 06:02:16 am
Quote from: ebclr on October 25, 2017, 02:11:22 am
https://pt.aliexpress.com/item/TSSOP-MSOP-car-remote-control-key-chip-pin-SMD-DIP-chipIC-clip-clip-burn-folder/32535219524.html?spm=a2g0s.9042311.0.0.by4JMI
Those clips are indeed tiny, might be small enough to work.

I flashed the coreboot firmware successfully. Still working on improving my grub2 config, and possibly might recompile coreboot again and modify its config, it is much like configuring and compiling Linux kernel, there's plethora of settings and it never feels like you're done.  Coreboot in itself is "only" minimal code for initializing a mainboard, after initialization it jumps to a payload, in my case payload being grub2

(https://i.imgur.com/SanPGV8.jpg)

bye bye CIA/NSA/FBI, no more proprietary/shady 5.0MB mini realtime OS running in Intel ME subsystem.  :-+