TL;DR: My particular 5.25" drive started spinning probably a bit too fast when used externally on cheap USB + 12V to SATA adapter.
So I got a 5.25" drive from an old PC that I wanted to use as external with USB SATA adapter. I mean, I have a slim portable one, but 5.25" is cooler, you know.
It seems the controller, laser and tray motor are powered from 5V rail while spindle and laser assembly motors are powered from 12V rail.
In my case, 5V source was USB on laptop and 12V an external power supply with the cheap SATA adapter.
Reading worked, so I tried burning a DVD+RW. Brand new undamaged disc. Unfortunately, it seems the higher power required caused too much voltage drop and it kept failing. The drive states 5V@2A and 12@2.5A max. USB tester looked fine on source side, so probably the cheap SATA adapter’s resistance was to blame.
Clearly, looking at the burned area, there wasn’t enough power (or something else failed):
Stripes
Well, the failure was interesting. A few times it just stopped communicating and I had to unplug and plug it back in.
But the other one was that it would just spin up from 4x to god knows what high speed until K3b shown I/O error and ejected the disc after a couple seconds.
Last time I tried playing with it. When it started speeding up, I started toggling the 12V power supply. No I/O error, and K3b shown “0.8x”, but I got bored of it and it probably wouldn’t write anything readable anyway.
So, I turned the 12V back on and let it go full throttle. I/O error, and split second after it started spinning down a faint crack sound. And there we go, the disc started cracking, it would probably shatter soon after.
I also tried burning a Memorex DVD+R at 16x. I put front of the drive into a plastic bag to contain potential shrapnel, and started burning. Nothing interesting. I set it to 16x, it kept bouncing between 5 to 7x and produced nothing readable (just stripes again).
It says post anything, right?
KClassics are usually not that bad in case of food, but indeed, O wouldn’t trust them with DvDs.
Ahem, I’d actually really want to find more of them. This was the last Kaufland DVD+RW I had, sadly.
I had some other RW discs fail after a couple rewrites, but these only ever became unusable due to scratches. They seem to be pretty good.
The thing with DVDs is, you never know who the manufacturer is until you buy it and read the media ID. Brand name in this case means shit. Maybe with the exception of Verbatims with AZO dye.
These Kaufland discs have media ID: CMC MAG/W02
So, the manufacturer is CMC magnetics.
Searching the specific media ID, it also shows for following brands: TDK, Memorex, HP
CMC magnetics makes discs for a lot of brands, hell, nowadays even Verbatim is fully owned by CMC. (but the quality will differ)