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As someone who's only dabbled lightly with electronics, maybe I was just doing it wrong, but I didn't have great luck with those Pomona SOIC test clips. While
by neilv 2y ago
As someone who's only dabbled lightly with electronics, maybe I was just doing it wrong, but I didn't have great luck with those Pomona SOIC test clips.
While doing in-circuit SPI flashing of several laptops for Coreboot, getting a good read or write was difficult. One of the many things I'd regularly try was to reseat the clip. Unfortunately, with the Pomona clips, this reseating would tend to catch and push in the pins of the clip, so they started making even poorer contact.
This pushing in was possible because there's not a single rigid pin straight through from the component to the test headers. The pin is 2 or 3 (I forget) parts, and a lower part can pop out of the plastic channel/groove it's in. You can disassemble the clip and push things back together, but it wasn't quite the same as before deformed.
I ended up having better luck with simpler clips that have a single physical pin straight through, such that the header pitch is the same as the component. Then I bent the pins to the side in an alternating pattern, to give enough room to attach my individual wires.
- baby_souffle 2y ago> I ended up having better luck with simpler clips that have a single physical pin straight through, such that the header pitch is the same as the component. Then I bent the pins to the side in an alternating pattern, to give enough room to attach my individual wires. I have had 100% the opposite experience :D. For whatever reason, the cheap clips quickly develop intermittent faults on some number of wires or the pin deforms hopelessly. You can tell the problem is getting worse when you have to maintain more pressure to hold the clip in place or do multiple reads and confirm that the sha1 hash of the dump file matches for the majority of reads!
- neilv 2y agoMaybe I just had clumsy technique. I was usually attaching the clip with not much room to open it beyond the component, which I guess might've contributed to pushing in the component-side pins.
- lemonlime0x3C33 2y agoI love Pomona SOIC test clips, the other cheaper ones off of amazon are garbage though. :) I find when flashing hardware you might have to try a few times and if you get a good read/write going don't move, don't breathe, don't do anything until it is done.
- schmidtleonard 2y agoWas it Pomona or Pomona knockoff? IME the real ones are eye-wateringly expensive but they actually work, whereas the knockoffs are dirt cheap and tend to require even more effort than soldering (between making initial contact and discovering+fixing intermittency problems).
- neilv 2y agoIt was Pomona-branded. They were either genuine, or very convincing-looking counterfeits. I had a few of them, and the materials and build quality seemed good, other than pin migration up that my use/abuse of them seemed to cause.
- dishsoap 2y agoIf you didn't pay upwards of $20 per piece, they were likely fakes. I have had the same experience as all the other commenters here: Pomona clips are the only ones I've found that actually work well, while all the cheap clips are just about unusably bad.
- neilv 2y agoI did pay upwards of $20 per piece. I think they were genuine, so, based on the comments here, my best guess is that I was abusing them. I got the much cheaper and simpler clips to tolerate my abuse better.
- yonatan8070 2y agoI tried some BIOS flashing with an Arduino Uno I had, a level shifter to 3.3V, and a SOIC clip from AliExpress. I had tons of issues connecting to the chip, so I moved to an old RPi I had laying around, and it just worked flawlessly, every time. I assume it was the level shifter but I can't be sure