Dat 70's smell - Page 1
Forum section: electronics / general

author: erajomppa
author_rank: Newbie
timestamp: June 29, 2016, 05:12:24 pm
content: To start off I'll tell that I am myself -90 vintage so these components are almost twice my age, but the nostalgia come from my childhood when I used to tear apart anything electric that was about to be thrown out.So I am doing an internship at a company that makes furniture and industrial fixtures from metal. We are in a process of moving from one factory to another and there is ton of stuff that is being thrown away (they have been hoarding crap for SO LONG). So today I got my hands on this... keypad with 7-segment numbers and stuff on itI honestly have no idea what it it, but something is wrong with it. It was being thrown to trash, but I spotted the 7-segment numbers and came to the rescue.pic:https://drive.google.com/file/d/18Sly00P5L16EoHjZIUVZ4oDBSK1mzDsAPQAt home I started taking it apart and found a TON of analog chips inside (on stands, so they are easy to switch/remove). The way these things are connected together though...must be a PAIN to troubleshoot what is wrong with this!pic2:https://drive.google.com/open?id=1mfrJj4ywQlQdXEubwEpf2g_uqZKErZUVrAWell I started harvesting the chips and tried to sort them, but there is just too many different chips in thisFinally I managed to sort them out with a help from a piece of packing foampic3:https://drive.google.com/open?id=1KHuM79ZdJZSNDz3zx8vYYjkLcoqvr87IkQpic4(finished):https://drive.google.com/open?id=19nZNwoNgbDQUnQhwXBOKsGR8o7pmfqjv9QBut THE SMELL! Oh mama! I'v already washed my fingers but I can still smell it. The smell of a motor from a taperecorder... the smell of old electronics, just the way I rememberDoes not smell anything like the new stuff I use in my RC projects. I guess the factory workers have changed their deodorant brandPS. Maybe I'll try to look through all the datasheets tomorrow and find out WHAT I just used a few hours to collect and categorize.PPS. sizelimit on attachments, so I'll just link to my googledrive pictures. easier that way... for me

author: rrinker
author_rank: Super Contributor
timestamp: June 29, 2016, 05:34:04 pm
content: OK you may have ESD killed the ones you stuck in the plain packing foam. What's the 40 pin one? I'm guessing an 8080 or 8085 CPU? The device looks like a controller for some sort of machine tool.

author: klunkerbus
author_rank: Unknown
timestamp: June 29, 2016, 06:33:17 pm
content: Back when everything was built with mostly DIP ICs, wire-wrap panels like those were often the way to go for a prototype or for a one-of-a-kind project. Given a properly annotated schematic and a point-to-point wire list, I didn't find working with them hard at all. Certainly worth the flexibility they offered in allowing changes to be made on the fly.I would bet the smell is mostly a result of where/how the thing was stored, not so much the electronic parts themselves.

author: erajomppa
author_rank: Newbie
timestamp: June 30, 2016, 09:41:51 pm
content: Quote from: rrinker on June 29, 2016, 05:34:04 pmWell, I was not going to be really careful with these anyway and I ran out of categorizable storage space. I hope nothing really nice got toastedYeah it probably is from a machine tool. My boss told me they have one machine that still uses the same panel, but we were too busy so I didnt have time to check out what sort of machine it was for. I'll try and yank his sleeve next time I remember.

author: erajomppa
author_rank: Newbie
timestamp: June 30, 2016, 09:45:01 pm
content: Quote from: klunkerbus on June 29, 2016, 06:33:17 pmIt might be a unique controller for the companys own machine. I'll try to figure out what it is from and if they have built it there themselves. I'm new in house so I dont quite know what sort of apparatus they might have manufactured in the past.

author: Alex Eisenhut
author_rank: Super Contributor
timestamp: June 30, 2016, 11:43:05 pm
content: What analog chips use a keypad and 7-segment displays?

author: helius
author_rank: Super Contributor
timestamp: July 01, 2016, 12:01:34 am
content: Old electronics often have a distinct "phenolic" smell, from the circuit board substrate material outgassing.

author: TerraHertz
author_rank: Super Contributor
timestamp: July 02, 2016, 01:13:11 am
content: Quote from: erajomppa on June 29, 2016, 05:12:24 pmFrom the chip numbers I can see, they are not analog, they are 4000-series CMOS logic. Nice stuff, runs on power supply from 3V to 15V, very noise-immune, easy to use due to relatively low slew rates not needing much attention to HF effects.BUT... they are also highly sensitive to static electricity, and since you weren't aware of that, probably didn't handle in static-avoiding manner, and also stuck them in polyethylene foam (good generator of static charge) then put them in plastic drawers (more static charge generation) you may have killed a lot of them.The right way to keep these is in anti-static tubes, or wrapped in aluminium foil, or stuck into black conductive foam.Next time you find a board full of nice parts in sockets, better to check out the data and learn the necessary precautions before disassembly.The construction technique is called wire-wrap. Generally used for prototypes and very small-run production. It's OK, no worse than ordinary PCBs for service, since it's assumed there would be a circuit diagram and so no need to follow wires.Whoever did that board though, didn't do the wire-wrapping terribly consistently. Supposed to be at least 1.5 full turns of insulated wire around the post, for better resilience against breakage.

author: erajomppa
author_rank: Newbie
timestamp: July 03, 2016, 06:26:28 pm
content: Thanks TerraHertz, lots of stuff I was not familiar with. I'v been doing most of my electrics stuff with arduinos etc and never have I had a problem with static electricity, so no precautions were taken.Well, I hope some survived. I am seriously running out of space to store stuff and I have not kept all the anti static bags. I threw away a lot of bags, black and clear, to make room for other stuff. I do have some aluminium foil so I could coat my plastic drawer with that maybe? would that help?Anywho. I did dig up some of the stuff (the ones in the drawers). I got Resistor networks, latches, flip-flops, buffers, shift registers, reed relays and of course those gates. AND, OR, NAND and AND/OR gates.I might play with those gates at some time (if I have the time). But now they are back in their non-protective drawers.https://drive.google.com/open?id=1MnZhb6fQJdI5_K2r4IpDAJozP79Yes-ysQPS: The big one is MK50395N. Six decade counter / Display driver

author: radar_macgyver
author_rank: Frequent Contributor
timestamp: July 03, 2016, 06:33:45 pm
content: Since the 4000 series parts have a 'B' suffix, they're buffered and a bit less sensitive to ESD. They're likely OK.

author: Kjelt
author_rank: Super Contributor
timestamp: July 03, 2016, 08:58:46 pm
content: Put a sheet of tinfoil on top of the foam and start again.

author: erajomppa
author_rank: Newbie
timestamp: July 04, 2016, 04:30:54 pm
content: The timing is great. I just got a load of stepper motor driver modules from ebay today and now I got 20 ant static bags I can use. They are very small though. and only 20 of them.Anyway. I did bag most of my gates, since I think they are the ones that I might actually use. I didnt go all foil-hat on the rest of the drawer yet... I will put a sheet on top of the foam though, that sounds like a great idea.https://drive.google.com/open?id=1fFdoh3gS63JIdgI8Z0siVBoFzHkD6N3KMwhttps://drive.google.com/open?id=1Chtwv9r86xRJQ4-Tp0u6ONOcJMZhYml5mgI also came across a mystery part. The text on it is as follows:""""RIFA x924PBD 352302"""""pic:https://drive.google.com/open?id=1EHNikrBAndkVJiOsvpAuifayagXEWOxajwI cant find anything about this thing online. I tried splitting the numbers and searching all the words separately and pairing them differently. Both on google and alldatasheets... help