16/10/2026
Anyone who talks to me often enough might be "lucky" enough to hear my rants about the ensh*ttification of all manner of stuff, from little Holden Cruze CV shafts (I'm on number 5 in around 60000km) to aftermarket Saginaw power steering pumps that whine more than I do when sooking about ensh*ttification!
Well, if you haven't heard it yet, keep reading.
Even worse than plain old poor quality parts, is fake or counterfeit electronic parts. There's plenty of evidence for this, with numerous people finding relabeled crap getting sold, even by reputable companies. AliExpress, eBay, Amazon, etc. are all infested with fakes.
Which brings me to talk about the 2N5686 power transistor (as used in Ford blower fan resistors and such; see the other post for more). They're an 80V, 50A NPN device, in TO3 package, so they're pretty beefy for an old design part.
I've been bitten by fake semiconductors before, and they waste a lot of time and resources, plus the possible reputational damage when they give trouble. I had a few of these in a drawer, and I was suspicious of them. I had to use one in a job, so I thought I'd better check them all out to find the dodgy ones. I enlisted the help of our family Veterinarian, who was very generous with their time and X-ray machine. Apparently, the "rat skull" setting worked ok.
Out of the 5 transistors checked, 2 were fakes and three were genuine Motorola parts. I did destructive tests (cut open) the two fakes, plus a dead genuine part. I also weighed them all on a tiny scale, of the kind the cops would be chatting to me about if I had it in a pocket. I'll attempt to explain and document everything further in this write-up as captions with the photos.
I used one of the genuine parts in the blower fan resistor repair and it worked like it should.
Given that you can't annoy your Vet every time you need to, I think weighing the device, and comparing the numbers to the old parts might help ensure you aren't using junk parts. Also, solvents like acetone may remove the numbers printed on dodgy parts.
