[sdiy] IC ID?...

[harry]

Hello Two-Seven-One  (et al)

If you have the boards... you should study the chips in
context.  If it is from a clock radio... is it from the clock...
or the radio...? What are the pins connected to ?

Most cases careful study will yield the identitiy of the chips...
I had a case where I blew up a unit (360 Systems Slavedriver) while
trying to diagnose a power supply problem. There were about
15 chips... with the numbers carefully sandblasted off.  One of these
chips
had a hint of a 4000 series CMOS part number. Tracing the rest of the
chips
showed the power pin to be 14 or 16...and the grounds to be 7 or 8. So
I surmised that most or all of them would be 4000 series as well...

Then going from the one identified chip I found where outputs must be
(connected to inputs) and where inputs must be (connected to outputs)...

Until I came to one gate (the BAD one, of course...) that had outputs on
pins 1,2,12,13.... and the rest inputs.

Now what chip is THAT (contest question)....?

You might tell if the chip is connected to a lot of coils etc... or to
the
radio tuning buttons... that it belongs to the radio... or if it has
outputs
that terminate in the LED / LCD display that it might be a clock counter
driver chip etc....

That said... I have two
Beckman 7556CU chips
.6" spacing... 38 pin ceramic package...
with a small chip cover at one end of
about .4" by 1 "

These were samples... probably early
80's.  Beckman was a maker of precision
resistive components (primarily)... so I
suspect I'm lookat at a resistive ladder or
some A/D or D/A chips.

NO... its not a dual timer, right   ;^)
And Google turned up a blank.

I don't need to find out, just curious

H^) harry

Studio 271 Productions wrote:

> Since we're on the subject of identifying ICs, I thought I'd chip in
> (pun intended, but don't we have enough puns as it is?) with a few of
> my own that I need help with:
>
> UM9559F [16p] (Answering Machine)- Looked it up, saw stuff on sound
> generation, but no datasheet...
>
> MC14021BCP [16p] (Phone) - Dunno what...
>
> KIA494P [16p] (Comp. Power Supply) - PWM chip? Also have a GL494 from
> a phone, but can't see why a PWM would be needed in a PS...
>
> CXA1019S [30p small pin spacing] (Clock/Radio) - Know it is some kind
> of radio chip, but no datasheet...
>
> IR2425 [14p] (Unknown Source) - Have 3 of them, but have no clue what
> they are... Also says "Sharp 221c", but checked Sharp's site to no
> avail...
>
> 2061D [20p] (Unkown Source) - Got the board from someone's chemistry
> project at school, know nothing about it...
>
> Please help if you can, and if the message seems too ungrateful for
> the viewer's eyes, I'm very sorry... I just want some help... I was
> up till 2 in the morning last night desoldering about 40 ICs from
> boards I had in a drawer, and I'll probly spend the rest of the day
> getting the components off of these same boards so I can throw them
> away and get some space back in my work area (maybe I'll even use a
> fan this time, so my eyes will stop hurting from the rosin fumes);
> Plus I'll be repainting my desktop soon, So I need the thing
> organized... Busy, busy, busy...
>
> -271

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