Chasing the Sony CX20084 speed chip for D6C walkman

Of couse it's a good idea to ask for tests.
Observing the actual speed is a more definitive test, as the fact motor always runs is a symptom that doesn't always manifest or may not be obvious.
Difference in speed is obvious (as is the increased noise from the motor running fast): when chip is burnt PLAY will look like FF.

 

So I wanted to share something with you guys... I did some searching around, contacted a USA based company, who had in stock some CX20084 IC chips and requested information from them. Even though the company had said that they can't do any electrical testing in house, I was pleasantly surprised that they offered to provide a detailed inspection report on the chip, which I have just received and have attached it for your review. It is several pages long and in PDF format. I had to remove some personal data from the report but all the relevant info is there. If you have a few moments, please have a look and let me know if this is something worth looking into. Now let me just say that the chip (from the images) doesn't appear genuine BUT I am not ready to dismiss it altogether. It appears at least like a good copy of the original or maybe it's Sony late production? Note the date code "0629", which is 2006, if I'm not mistaken. Also "assembled in China / Diffused in Japan". What the hell does "diffused" mean? Also the price is $59 USD per chip. Lastly, the company who is distributing this chip (among many other chips) seems legit from my research and is based in the USA. Anyway, let me know what you think.

 

Diffusion is a part of semiconductor manufacturing process. It's common for a chip to be packaged in a different country from where the wafer is manufactured.

SONY switched to CX069 for the last D6C variant (in June 2001, while production ended in 2002) so not sure if SONY still produced these ICs in 2006 (would incline more towards a no).
Also issue about the date code is I only see that on the package, not on the chip itself.
For example, early genuine ones had the date code clearly visible on the chip (see pic attached), but later ones not. Early ones didn't even have the SONY logo, which appeared on later ICs.
Issue with looks alone is some of the late chips SONY produced do look similar to the fake ones.

What we are interested in is electrical testing, otherwise there's just no way to tell if the chips are good and reliable.
Can't dismiss it, but can't recommend it either unless I get to test some of these ICs myself.

What I can tell is at the $59 price I would expect the chip to work both when installed and long-term.
The big advantage with a known good genuine one is this: if it works the moment I install it, it will work long term. That cannot be said for the fake ones.

Don't think we can give you a definitive answer so you can make a risk-free decision. You have to test for yourself.

 

Given the switch to the CX069A (used earlier in the 70s as mentioned before in a thread on S2Go), CX20084 were apparently very hard to source in 2000s.
Why would Sony change the complete circuit board, switch from one obsolete IC to another very old one + an additional IC, just for 1 production year?
And to top it off, also the 35711 head was no longer available and had to be replaced in this last year of production by a less durable 35712 head, not amorphous, while that was one of the selling points of the unit?
Why not call it a day just prior to what we now know as service manual 1.1? All the work for a few additional units at the end of its lifespan?

 

@Valentin @Emiel thanks very much for the replies, I might just ask them if they have the electrical testing results or datasheet from the manufacturer, and see what they say.

 

Speaking as someone who sometimes deals with component obsolescence at work I can think of two reasons.
1) Parts bin specials. If they had a load of cases and mechanisms but no ICs or heads switch to a different type.
2) If the ICs were made in different fabs (semiconductor factories) and one shut down or changed its process switch to an IC which a different fab can still make.

p.s. If they switched to a small external fab some of those have a reputation for parts (sometimes rejects) leaking out of the back door.

 

@Valentin this reminds me of some cassettes from MAXELL or TDK, would say on the box "Tape made in Japan. Assembled in Mexico." So if true, what we might have here in essence is the IC being "made" (diffused) in Japan but packaged in China. Interesting.