When is used used up?

TVAD-- I defer to the responses of Elizabeth and Stevecham.
Garn509 (Answers)

No deferral necessary. I was asking Elizabeth.

OK, Tvad, no question it is old, and may become junk with a few hours use. (since NO parts will be available to fix even simple items like a belt or pulley) It has rubber belts in it that drive the mechanism from the motor/motors. Do you think those belts are going to just not age? IF they are made out of a synthetic (it would have to be a $$$ Nakamichi), maybe they won't break right off. but do you think it is fair to list it "as new" and NOT reveal that it is in fact AT LEAST 15 years old?
And that NO specialty parts are going to be available?
That is the problem.
If you DID say this machine has sat for 15 years with little use etc, then I guess a buyer can make a fair decision as to whether they are going to take the chance. It is when a seller does not reveal the 15 year age, just "looks great" that it becomes a shady deal.
Personally I would NEVER buy a 15 year old mechanical device EXCEPT a turntable and that only if it did not have an idler wheel design.. (only because the motor does just one thing..and the plain bearing in a turntable is pretty indestructable.)
Something like a cassette player, a video recorder, An open reel machine, a CD player.. hah... I would surely pass. I want stuff that works.. not a new project.
And, finally (deep breath here) IMO any cassette deck is junk because it it a dead format. It belongs out there with eight-track machines, Beta video machines, laserdisc players, 78 rpm turntables.. this is, of course, just my opinion. Some folks lives may revolve around restoring and using eight-track machines...
I've thrown away my cassette players, and tapes, thrown away my Beta machine and tapes, thrown away the VHS machine and tapes, thrown away the LD players and laserdiscs.
Thrown away generally means gave away to a Goodwill. Where folks can buy junk and have a seven day return on all electronics (since they pay maybe $5 to $20 bucks.. it ain't a big risk.)
I hope this clarification answers your query about your cassette deck?

Thank you, Elizabeth.

The one last chunk of 'old junk' or treasure: cartridges.
How old ARE some of these "It has been sitting in my drawer and I decided to sell it"
I saw a Dynavector Ruby 23 for sale as such an ad. Wanting $450. for 25 YEAR OLD CARTRIDGE.
Just by coincidence, last year a fellow employee gave me a Rega P3 with a Magnepan Unitrac arm with a Dynavector Ruby 23. He had it for over 25 years, and used on occasion it all that time. (He was fastidious, and kept it very clean using an ultrasonic Denon device)
Now I do have to say it still sounds good. but how old is old for a cartridge?
Actually my only complaint is not revealing the actual age in the ad.
If someone wants a 25 year old cart for $150. more than it cost new...
I mean I have no complaints with mine.. I got it for free AND knew exactly how old it was and how much it was used and how it was cared for. (I have the original receipt)

Concerning purely electronic components (as opposed to electromechanical ones), my experience has been that, as Elizabeth said, it's a tough call. And it is very unpredictable, even when environment and usage history are taken into account.

During the 1990's I owned examples of a lot of the better vintage amps, preamps, and tuners from the 1950's and 60's. Some of them worked spectacularly well, some of them just didn't sound right, some of them had minor problems that I easily fixed, and some of them had problems that I either could not fix or chose not to fix, so as not to ruin originality.

Capacitors seem to be a major variable, as a function of the particular brand and year of manufacture as well as the usage history. I am not aware, though, of any comprehensive summary of which were the good ones, which were the bad ones, etc.

I've had very good luck with a number of FM tuners of the 1950's and 60's, even though a tuner figures to be more critical than an amp or preamp due to misalignment that can occur over time due to drift in component values. In my main system I presently use an all-original 1954 REL Precedent tuner, which works spectacularly well in terms of both sound quality and station-getting ability (except for some days when an intermittent problem appears, that I haven't been able to resolve).

I also collect antique radios. I have an elaborate two-chassis E. H. Scott console from 1932, which I believe is completely original including even the tubes (including a pair of push-pull 45's in the output stage :)). It also works spectacularly well in terms of both sound quality (AM only, of course) and station-getting ability. However, on a higher-end E. H. Scott model from 1940 that I also have I had to replace approximately 50 capacitors, some of which went up in puffs of smoke.

Both the good-performing 1932 model and the problematic 1940 model, btw, spent all of their years in the same geographical area, here in Connecticut.

And I am aware of several instances in recent years, involving high-end professional video equipment and also computer equipment, in which bad runs of capacitors resulted in a rash of failures after just a few years.

So it is a tough and unpredictable call. But my experience suggests that in the better scenarios older electronics can continue to perform well for far longer than might be expected.

Regards,
-- Al