Can anyone help with chip dates?
I’ve been trying to pin down the age of the BGM machine I’m working on. To me the design feels 1988-1992, but that’s just a hunch.
This task is not made any easer with this being a commercial device as the dates for these are harder to pin down based on fashion. The internet is of no help and I can’t get to the motor to see if that has a date sticker.
My last hope for finding a date was the chips as sometimes these have date codes on them, however on this occasion I’m not seeing anything that clearly confirms a date. If you’re a chip expert could you have a glance over the pictures I’ve posted here and see if you can decypher anything from the text printed on them.
There are seven chips - some were easier to get a good angle on than others (the last one I've uploaded two pictures of) …but these are the clearest pictures I could capture.
UPDATE - We’re going with 1988 as the most recent date.
Comments (39)
In the 1980s, chip manufacturers often printed only the least significant digit of the year to avoid confusion with chips that might have type numbers that could look like date codes. So instead of 87xx or 88xx you might see 7xx or 8xx.
Thanks for giving me yet another opportunity to experience failure! I tried finding the data sheet for the Hepta-Darington Array IC (M54519P) on the chance that it might describe the date code. I did find a copy of the data sheet (http://datasheet.elcodis.com/pdf2/89/48/894877/m54519fp.pdf), but it does not describe the date code. For what little it’s worth, the data sheet itself is dated August, 1999. If you feel you really must know, which apparently you don’t, you could always try contacting Mitsubishi Electric (https://www.mitsubishielectric.com/en/contact/index.html) directly, explaining that you are a beloved global celebrity and influencer, and demanding the information. Best regards, and pip-pip!
``explaining that you are a beloved global celebrity'' OMG! He is, isn't he!! :-D
Just for the future - you could get some cheap endoscope camera, so you could get to the motor and just read the date without having to take everything apart or decoding the chip manufacture dates. Although it would be useful only in cases where you could get to the motor with endo, but it's just a suggestion
This info isn't something I would ever need - but I enjoyed reading through it, anyway. I had no idea it was so difficult to pin down chip manufacturing dates. 🧡 this community and channel.
And seeing as we're on the topic of machine innards - look at these little Sony caps in a transistor radio I found online yesterday: https://ibb.co/HqT822b
I work for a small electronics manufacturer and have been repairing stuff for (scary!) 50 years or so. Sometimes the dates will be a bit off, due to older bulk purchases and, sometimes, a manufacture dropping a part, so you have to hunt them down. (May explain the one '84 dated part...:) 88 for the win here. I'm more up on US chip date codes, that National part helps...:) Keep on ferreting out these neat widgets! Still have to send you this Kenwood DC-20 unit one of these days. Want to fix (belts) the tape transport tho. Very capable tape system, essentially a mid-line home transport in a portable unit. (Can record metal, dolby B, etc. And has a flywheel that weighs more than 3 or 4 of the newer complete 'transports'...:) Some day... Off to fix what the packrats did to my lithium house backup system. (Seems they don't like the silicone wiring in the battery bank, but the BMS wiring is fair game:) Stay retro! Blessings! Stu
You are welcome. Looking forward to a video about an odd tape recorder with some "non Dolby" dynamic noise reduction system.
I'd like to say a huge thank you to everybody who replied. I felt proud we could all help Mat today. Best wishes everybody!
I used to teach a course in microelectronics back in the late 80s, and while most ICs of that day had a date code (YYWW) not all did. As a previous commenter pointed out, the most likely date for the board is a bit after 1987. The SM8730 was the best clue for me. Bear in mind that a lot of older parts may have been used.
M54519: 1988 week 02 NJM2043: 1987 week 01 NJM4556 : 1987 week 03 HD14052BP: 1988 LM1894: 1987 Week 30 (those are the easy ones) uPC1043C: Surprise: 1984 Week 39, old TA7245BP: 1988
Insert mic drop for Holger!
Mat there may be a date on the printed circuit board too. If you can take a photo we might get the production date closer.
I couldn’t see one
The Nichicon (and others) electrolytics have a date code also (usually)
Capacitors?
Mat, The National chip is very likely 8730 Year 87 week 30. NEC week 43 year 90. Toshiba 8808K would be Week 08 Year 1988. The Hitachi 8C4T year ending 8, 3rd week April. Hope that helps.
The last two letters on the NEC chip are 9D - does that change anything?
It seems that the consensus is that the most recent chip is from 1988…anyone disagree?
I AM NOT AN EXPERT but I do watch enough 'tubers with hot soldering irons to recognize chip logos ... Nat Semi (the horizontal lightning bolt logo) date codes seem to be YYWW, so 30th work week of 1987 for that one, possibly. https://www.vintage-radio.net/forum/attachment.php?attachmentid=231204&d=1617886212 The Mitsubishi chip -- 802001 -- seems to be the 8th year and the 02th week and if we accept that the NatSemi chip was the 33rd week (or 33rd work week) of 1987 then the 2nd week of 1988 at least makes sense. https://telcontar.net/KBK/tech/IC_dates HTH!!
We’re going with 1988 - thanks for your help.
Someone who could help is @curiousmarc. He has a channel on YouTube and does this all the time.
I suppose to narrow it down a bit more ...could anyone tell me the date of the *most recent* chip, that’s the one that’ll help me pin down an approximate manufacture date as it definitely can’t be made before that.
Best guesses... 1- Jan 20, 1980, 2- 15th week of 1970, 3 - 35th week of 1970, 4 - (a proprietary date code), 5 - 30th week of 1987, 6 - 43rd week of 1990, 7 - no clue.
The last two letters on the NEC chip are 9D - does that change anything?
There's a mix of 87-89 in there. Figuring out the age is complicated by the fact that a few are currently produced parts and the short hand has changed.
Thanks - so the most recent one you see is from 1989?
According to this, the Mitsubishi chip is from 20th week of 1980...or not. https://telcontar.net/KBK/tech/IC_dates#Mitsubishi
I agree
this site is usually helpful https://telcontar.net/KBK/tech/IC_dates
so 2nd week 88 for the first chip above? hitachi chip seems to be March 88
Unfortunately, there is no agreed upon standard. I personally have used YYWW and WWYY in my job as PCB designer. However two look like YYWW to me LM1894N - 8730 is probably 30th week of 1987, TA7245BP - 8808 is probably 8th week of 1988
Yes I agree here. The other chips don’t have usable date codes while these two chips do. So it would place this device at least early 1988.
I found a publication from NEC on that integrated circuit from July 1982. I’m terrible at reading chip dates, but this might prove useful: https://www.digchip.com/datasheets/download_datasheet.php?id=1473383&part-number=UPC1043C edit: the Hitachi chip date code is weird - they only use one digit for the year, the month is signified by a letter and then the week of that month. So my best guess for “8C4” is - 1988-March-4th week?
The Toshiba chip is almost certainly the 8th week of 1988. The only one that really mystifies me is the NEC chip. Maaaybe 1989? Everything else seems to point to late 80s but that one is a mystery to me
I'm guessing the NEC chip may be the 43rd week of 1990?
The last two characters on that one are 9D
1970's for a few of them.
sometimes only the last digit of the year is shown instead of the last two digits, I would guess the 7 actually refers to 1987, with two digits for the month following & run number last.