M1593FP on PEA1291 from PD-204
Download: M51593FP / M1593FP datasheet (PDF)
Having finally located the service manual for the Pioneer PD-204, I then ran into a further dog's cunt concerning the datasheet for the RF preamplifier IC in the optical pickup.
While the above-linked service manual is a sight better than nothing, it is still quite shit, because it was scanned by an idiot and the resolution is too low to read most of the legends on the circuit diagram unless you can take a guess from context to start you off working it out. The type number of the IC in question is so afflicted, and since IC type numbers are just a bunch of random characters with no sense to them, context is absent. On the other hand, reading the type number off the IC itself is quite easy, as shown by the photo on the right. (It is a lot easier in real life than in the photo, because the camera is fucking shite.) And that number is, quite clearly, M1593FP.
So that was the search term I used to look for a datasheet, and could I find one? Could I arse. I had more "success" in finding forum posts from other people who have also taken apart a Pioneer CD player that uses this chip and also can't find a datasheet, except I wasn't looking for that. Widening the search term to something like "optical pickup" preamplifier mitsubishi didn't do the trick either. I found datasheets for a few other chips matching that description, but from their pinouts alone it was obvious that they were not different versions of the same thing.
I did notice, though, that Mitsubishi part numbers for such chips tend to have five digits, not four, and the first digit is usually a 5. And looking again at the fuzzy blobs that make up the legend for that chip on the circuit diagram in the service manual, it did seem possible to read them as a type number with five digits between the letters, as well as the more obvious reading suggested by the marking on the chip itself, which is four digits and a bit of fly shit.
So I tried another search, this time using M51593FP as the search term. And... bingo. There it was, and comparing the datasheet with the circuit diagram it's pretty clear that it really is the same chip, despite the extra 5.
It seems that the important fact, ignorance of which is confusing the shit out of everyone on the internet who has this problem, is this:
M1593FP and M51593FP are the same fucking thing.
Fuck alone knows why the part number on the chip itself is missing the first 5, but there it is, and a huge fucking pain in the arse it is too. Perhaps with a bit of luck the existence of this web page will help anyone else who encounters the same chip in future to avoid the totally unnecessary confusion generated by that wrong marking.
Download: M51593FP / M1593FP datasheet (PDF)
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