8 Apr
2012
8 Apr
'12
4:17 p.m.
-----Original Message-----
From: cctalk-bounces at classiccmp.org [mailto:cctalk-
bounces at classiccmp.org] On Behalf Of Brent Hilpert
Sent: 08 April 2012 22:22
To: General Discussion: On-Topic and Off-Topic Posts
Subject: Re: RD53 Disk Not Rotating
On 2012 Apr 8, at 1:34 PM, Rob Jarratt wrote:
Indeed, the other power transistors are all 87xx, so it must be date code as
you say.
Regards
Rob
I hope I haven't made a mistake here. Rather
than go to Farnell where
I need a minimum order amount, I looked on Ebay and found someone
with
some TIP125s there.
I had assumed they were all the same and just chose this one:
http://www.ebay.co.uk/itm/TIP125-Transistor-/290672643190?
pt=LH_DefaultDomai
n_3&hash=item43ad708c76.
I haven't spent a lot, so if I have bought the wrong thing it is no
big deal to go and find the right ones instead. On the original the
only other marking (apart from a TI logo) is "8702", but my web
searches don't seem to indicate that this means anything. The Ebay one
has no other markings to help me distinguish anything either. So, I
don't know if I have bought the wrong thing or not.
Are they all likely to be similar enough not to matter? Or should I be
looking for a closer match? Not that I know what a closer match would
be.
Looks fine, the TIP125 is what matters.
The 8702 on yours is most likely a date code. Many semiconductors and
other components have a date code stamped on them in addition to the part
number and manufacturer id/logo. One of the most common forms of date
code (particularly for North American manufacturers) is yyww where
yy=LSDs of year, ww=week of year, so 8702 would indicate the device was
manufactured in the 2nd week of 1987. Look at the ICs in your drive, they
may have similar codes for around the same period.