Places to source obsolete semiconductors? - Page 1
Forum section: electronics / projects

author: TERRA Operative
author_rank: Super Contributor
timestamp: October 25, 2018, 05:13:52 am
content: In the course of restoring old gear, I often seem to find myself searching for old and obsolete semiconductors.Some of this stuff seems to be practically unobtanium, so I am wondering if you guys and girls have any suggestions for companies that might stock old silicon?Even via fax, mail, telegraph is all ok, I can work with old-school to get my partsI don't care where they are, as long as they can sell me some parts!For my latest misadventure, I am attempting to repair an old nixie tube Casio calculator from the early '70's, which uses p-mos chips... If anyone happens to have a handful of uPD101C chips laying around, let me know!

author: DC1MC
author_rank: Super Contributor
timestamp: October 25, 2018, 05:55:40 am
content: You want to say that you'd like to have VERY CHEAP ones ?Because fleabay has TONS of uPD101Chttps://www.ebay.de/itm/UPD101C-Halbleiter-GEHAUSE-DIP14-HERSTELLER-NEC/401410781008Just not cheap.Cheers,DC1MC

author: TERRA Operative
author_rank: Super Contributor
timestamp: October 25, 2018, 06:13:21 am
content: Nope, I bought a uPD101C from that seller and it was a fake.They seem to dropship their parts from China, so the few times I have purchased from them in desperation, I got used parts (that were sold as new) or badly faked parts in the case of the uPD101C.

author: digsys
author_rank: Unknown
timestamp: October 25, 2018, 06:40:25 am
content: Many eevblog members have heaps of old components, so it's worth listing what you are after here. Unfortunately, I don't have that one.You can also try ham-fests. Lots of old stuff there.

author: DC1MC
author_rank: Super Contributor
timestamp: October 25, 2018, 06:47:35 am
content: Oh well, I've bought actually some stuff form the guy and it was OK, with those things there is always a crapshot. Personally I would not mind an old unsoldered chip, as long as it still works and the price is reasonable. Bests letting your device to collect dust.You could try anytime the Russians:https://www.chipdip.ru/product/upd101Cheers,DC1MC

author: TERRA Operative
author_rank: Super Contributor
timestamp: October 25, 2018, 06:57:50 am
content: Yeah, I bought a replacement jungle chip from that seller and it worked and was genuine, just used (pulled from a socket) not new as advertised. No big deal there.I just don't want to risk my Casio 121K desktop calculator to what looks like an obvious fake. If I pop one of the big 'cpu' chips, all the calc will be good for is to be made into a clock...I'll put a post up in the wanted section, there are a few random chips I need for various things.I'm almost desperate enough to crack out google translate to poke that Russian website... If they ship international..Good idea on the hamfest thing, I'll have to see if there is anything like that in Tokyo.The last few semiconductor shops in Akihabara have turned up dry so far..

author: Benta
author_rank: Super Contributor
timestamp: October 25, 2018, 08:25:48 am
content: Rochester Electronics is an authorized source for obsolete parts. Many of the big semiconductor manufacturers sell their NOS parts to them when they are obsoleted.

author: Synthtech
author_rank: Regular Contributor
timestamp: October 25, 2018, 08:46:38 am
content: I am beginning to wonder if trusted suppliers in Europe and the UK are starting to re-stock from Chinese EBay sellers when it comes to rare parts. One reason for my suspicion is the much sought after MN3009 BBD IC which has been unavailable forever except from some UK, European and Israeli suppliers at high prices but they are all over EBay from Chinese suppliers and they are all fakes.People have been paying premium prices lately from previously trusted Western suppliers and they have been receiving fakes as well. Same for CA3280’s. Are these companies re-stocking from EBay and not testing their parts? It must be tempting. Fortunately reputable companies do give refunds but how did the fakes get into their inventory?

author: Synthtech
author_rank: Regular Contributor
timestamp: October 25, 2018, 10:47:22 pm
content: What is a uPD101C? I can't find any data on it.

author: digsys
author_rank: Unknown
timestamp: October 25, 2018, 10:58:46 pm
content: Quote from: SynthtechUse the force Luke ! Use the force :-)https://www.scribd.com/document/382712401/uPD101C-English-Datasheet-pdfQuad 2-in AND gate DIP14Selling fakes for UK$8-15 !!! Sheeet, Ima make a few :-)

author: TERRA Operative
author_rank: Super Contributor
timestamp: October 26, 2018, 12:43:27 am
content: Ha, you found the datasheet I translated from Japanese.I sent an email to the Russian company a few posts above. Let's see if they reply otherwise I might need to see if a friendly European forum member can freight forward for me.

author: rsjsouza
author_rank: Super Contributor
timestamp: October 26, 2018, 01:21:48 am
content: I feel your pain. I have an AS-A that had almost fully dried electrolytic capacitors on the power supply that may have damaged an IC or another. The calculator works moderately well for a few minutes and starts to become erratic. Also, division does not work at all, but that may or may not be related. These devices are quite difficult to source.

author: alsetalokin4017
author_rank: Super Contributor
timestamp: October 26, 2018, 01:47:51 am
content: Maybe?https://www.utsource.net/itm/p/389643.htmlI've had good luck buying from them.

author: woodchips
author_rank: Frequent Contributor
timestamp: October 26, 2018, 04:45:18 pm
content: findchips.com seems a good place to start, never actually had to buy any, yet.