On Thu, 11 Dec 2008 10:21:59 -0000, "N_Cook" put
finger to keyboard and composed:
Some hints for determining the age of equipment not marked on serial
plate,dating old kit.
Thanks for the tips.
Just as an exercise, I'm listing the codes on various ICs and
transistors that came out of an old Pye 3-in-1
tuner/cassette/turntable.
Sharp IR2E02 75YC 5 = 1985, Y = November, C = week 3
Toshiba TD6301AP 8720D 1987, week 20
Toshiba TC9147BP 8721H 1987, week 21
Toshiba TD6104P 8711K 1987, week 11
NEC uPC1225H 9241F - repair?
NEC uPC1225H 706D 1987, week 06 ?
NEC uPC1161C3 8713E 1987, week 13
NEC UPC1228HA 8728M 1987, week 28
Hitachi HA12045 6M4 6 = 1986, M = December, 4 = week 4
Rohm BA6124 706 170 1987, week/month 06 ?
Rohm BA3302 507 852 1985, week/month 07 ?
Rohm BA4558 701 535 1987, week/month 01 ?
Rohm BA4558 705 051 1987, week/month 05 ?
Sanyo 2SD313 E7E3 1987, E = May, week 3 ?
Sanyo 2SD313 E7F2 1987, F = June, week 2 ?
Here are more IC codes from a National VCR:
NEC uPD75108 8802EX705 1988, week 02 of year
NEC uPD4066 8734BN 1987, week 34
NEC uPC324C 8804C 1988, week 04
NEC uPC393C 8745C 1987, week 45
NEC 78M05 8802J 1988, week 02
Rohm BA15218 712 618A 1987, December (12th month) ?
Rohm BA15218 712 286A 1987, December ?
Rohm BA6246N 712 513 1987, December ?
Sanyo LA7308 8A5 1988, A = January, week 5 of month
Sanyo LA7098 7M3 1987, M = December, week 3 of month
Hitachi HA17805 7H4 1987, H = August, week 4 of month
Matsu****a AN3215K 7D.5 (D is underscored)
Matsu****a AN3321K 7D.5 (D is underscored)
Matsu****a MN1451 41 7 (no underscore)
Matsu****a MN1451 39 6 (9 is underscored)
Mitsubishi 5218 7Y02 1987, November 02 ?
Mitsubishi M5222L 7907 1987, September 07 ?
JRC 78M09A 7012 December 1987 ???
This page has some useful info (esp. for Hitachi):
http://www.datamath.org/Datecodes.htm
I can see the patterns for Sharp, NEC, Toshiba, Sanyo, and Hitachi,
and I can guess at the patterns for Rohm and Mitsubishi, but the rest
are a puzzle. I see that in your notes you have suggested that the JRC
year digits may be reversed, but this doesn't tally with the 78M09A
part. I see what you are suggesting for the Matsu****a codes, but then
how do you account for the MN1451BVK parts? I tried Geoffrey's
suggestion regarding Hirohito's coronation year (1926?), but I
couldn't make it fit the data.
- Franc Zabkar
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