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OP-AMP Long-Term Reliability
Gentlemen,
How reliable are the old 'tin-can' encapsulated op-amps from say 40 years ago? I'm talking about the ones that look like large transistors and have typically 8 leads in the TO5-8 package. I'm unable to provide a part number as these don't have one as such. Could be a 741 perhaps but I can't be certain. Are they known to fail? thanks. -- No deal? No problem! :-D |
OP-AMP Long-Term Reliability
On 2020/01/18 1:11 p.m., Cursitor Doom wrote:
Gentlemen, How reliable are the old 'tin-can' encapsulated op-amps from say 40 years ago? I'm talking about the ones that look like large transistors and have typically 8 leads in the TO5-8 package. I'm unable to provide a part number as these don't have one as such. Could be a 741 perhaps but I can't be certain. Are they known to fail? thanks. Many solid state devices from that era are still running. Physical damage (moisture working in via the leads) is one primary cause of failure. If the leads look good then chances are fairly good the device will work. I use lots of 30 to 40+ year old components all the time for servicing our classic arcade games. Most are perfectly good. Other than electrolytic capacitors...they definitely have a shelf life/best before date! John :-#)# -- (Please post followups or tech inquiries to the USENET newsgroup) John's Jukes Ltd. MOVED to #7 - 3979 Marine Way, Burnaby, BC, Canada V5J 5E3 (604)872-5757 (Pinballs, Jukes, Video Games) www.flippers.com "Old pinballers never die, they just flip out." |
OP-AMP Long-Term Reliability
On Saturday, 18 January 2020 21:11:24 UTC, Cursitor Doom wrote:
Gentlemen, How reliable are the old 'tin-can' encapsulated op-amps from say 40 years ago? I'm talking about the ones that look like large transistors and have typically 8 leads in the TO5-8 package. I'm unable to provide a part number as these don't have one as such. Could be a 741 perhaps but I can't be certain. Are they known to fail? thanks. The problem components from that era are lytics of course and glob-top transistors. NT |
OP-AMP Long-Term Reliability
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OP-AMP Long-Term Reliability
On Sat, 18 Jan 2020 14:12:19 -0800, John Robertson
wrote: Many solid state devices from that era are still running. Physical damage (moisture working in via the leads) is one primary cause of failure. If the leads look good then chances are fairly good the device will work. No sign of corrosion at all on the leads. I use lots of 30 to 40+ year old components all the time for servicing our classic arcade games. Most are perfectly good. Other than electrolytic capacitors. So do I. The question wasn't about NOS components, but components that have been in service for decades. -- No deal? No problem! :-D |
OP-AMP Long-Term Reliability
On 19/01/2020 8:11 am, Cursitor Doom wrote:
Gentlemen, How reliable are the old 'tin-can' encapsulated op-amps from say 40 years ago? I'm talking about the ones that look like large transistors and have typically 8 leads in the TO5-8 package. I'm unable to provide a part number as these don't have one as such. Could be a 741 perhaps but I can't be certain. Are they known to fail? **No. Provided supply Voltages remain within the limits set by the manufacturer, metal can OP amps, transistors, etc are phenomenally reliable. For a long time, all MIL-spec semiconductors were metal can only. They might still be, but I doubt it. In the early days of plastic encapsulation, some problems were notable. Mostly with power devices. Things have improved markedly over the years, but you will likely never approach the reliability of a metal can device by using plastic. -- Trevor Wilson www.rageaudio.com.au |
OP-AMP Long-Term Reliability
On Sunday, 19 January 2020 01:23:38 UTC, Cursitor Doom wrote:
On Sat, 18 Jan 2020 15:02:31 -0800 (PST), tabbypurr wrote: On Saturday, 18 January 2020 21:11:24 UTC, Cursitor Doom wrote: Gentlemen, How reliable are the old 'tin-can' encapsulated op-amps from say 40 years ago? I'm talking about the ones that look like large transistors and have typically 8 leads in the TO5-8 package. I'm unable to provide a part number as these don't have one as such. Could be a 741 perhaps but I can't be certain. Are they known to fail? thanks. The problem components from that era are lytics of course and glob-top transistors. OK, I have to know.. "Glob-top"?? http://www.ichom.org/Overig-499982/C...HILD-Glob-Top/ The round top is an epoxy glob covering the die, which sits on the flat thick sheet material that holds the leads. 2 tone ones make this easy to see, all black ones not so much. NT |
OP-AMP Long-Term Reliability
On 2020/01/18 5:26 p.m., Cursitor Doom wrote:
On Sat, 18 Jan 2020 14:12:19 -0800, John Robertson wrote: Many solid state devices from that era are still running. Physical damage (moisture working in via the leads) is one primary cause of failure. If the leads look good then chances are fairly good the device will work. No sign of corrosion at all on the leads. I use lots of 30 to 40+ year old components all the time for servicing our classic arcade games. Most are perfectly good. Other than electrolytic capacitors. So do I. The question wasn't about NOS components, but components that have been in service for decades. My first sentence in my first paragraph was my (getting tired of 'my') experience about original esolid state devices still running. Do please read what is written, I'm the only one here who is allowed to make the mistake of not reading entire posts before responding! John ;-#)# |
OP-AMP Long-Term Reliability
On Sun, 19 Jan 2020 10:10:50 +0000, Cursitor Doom
wrote: On Sat, 18 Jan 2020 19:35:36 -0800 (PST), wrote: http://www.ichom.org/Overig-499982/C...HILD-Glob-Top/ The round top is an epoxy glob covering the die, which sits on the flat thick sheet material that holds the leads. 2 tone ones make this easy to see, all black ones not so much. Ah. Ok. I have a few hundred of those but some obscure part numbers and all PNP so are unlikely to be called into service here. :) Those bring back not so fond memories. The black potting epoxy was optically transparent to infrared light. I had a hell of a time dealing with weird problems in the 1960's until I found the light sensitivity problem with those transistors. It took about a year for Fairchild to clear their inventory and screw their unsuspecting customers by continuing to sell these devices. Eventually, they changed over to the "PN" (TO-92) style package, which initially was made from silicon epoxy instead of epoxy-B. Silicon epoxy shrinks slightly at high temperatures, causing the corrosive fluxes from the wave soldering equipment to creep up the transistor leads by capillary action, and corrode the leads and chip. We had to x-ray the dead parts to determine the failure mode and guess the cause. It usually took about a month for the transistors to rot to death. I had a difficult time getting Fairchild to understand that having *ALL* the transistors on a PCB fail almost simultaneously after only a month was sufficient grounds for suspecting that something might be wrong with the parts. They eventually switched to epoxy-B, but only after again unloading their defective inventory on unsuspecting customers. There was also a problem with the UA2136 IF amp/detector IC, where chips made in different Fairchild factories produced radically different performance and stability. I took great pride in personally removing Fairchild from the approved vendor/manufacturers list, and finding alternate sources for about $2.5 million/year of their components. When I mentioned this to the sales rep, he acted like he didn't care or it wasn't important. -- Jeff Liebermann 150 Felker St #D http://www.LearnByDestroying.com Santa Cruz CA 95060 http://802.11junk.com Skype: JeffLiebermann AE6KS 831-336-2558 |
OP-AMP Long-Term Reliability
On 20/01/2020 9:55 am, Jeff Liebermann wrote:
On Sun, 19 Jan 2020 10:10:50 +0000, Cursitor Doom wrote: On Sat, 18 Jan 2020 19:35:36 -0800 (PST), wrote: http://www.ichom.org/Overig-499982/C...HILD-Glob-Top/ The round top is an epoxy glob covering the die, which sits on the flat thick sheet material that holds the leads. 2 tone ones make this easy to see, all black ones not so much. Ah. Ok. I have a few hundred of those but some obscure part numbers and all PNP so are unlikely to be called into service here. :) Those bring back not so fond memories. The black potting epoxy was optically transparent to infrared light. I had a hell of a time dealing with weird problems in the 1960's until I found the light sensitivity problem with those transistors. It took about a year for Fairchild to clear their inventory and screw their unsuspecting customers by continuing to sell these devices. Eventually, they changed over to the "PN" (TO-92) style package, which initially was made from silicon epoxy instead of epoxy-B. Silicon epoxy shrinks slightly at high temperatures, causing the corrosive fluxes from the wave soldering equipment to creep up the transistor leads by capillary action, and corrode the leads and chip. We had to x-ray the dead parts to determine the failure mode and guess the cause. It usually took about a month for the transistors to rot to death. I had a difficult time getting Fairchild to understand that having *ALL* the transistors on a PCB fail almost simultaneously after only a month was sufficient grounds for suspecting that something might be wrong with the parts. They eventually switched to epoxy-B, but only after again unloading their defective inventory on unsuspecting customers. There was also a problem with the UA2136 IF amp/detector IC, where chips made in different Fairchild factories produced radically different performance and stability. I took great pride in personally removing Fairchild from the approved vendor/manufacturers list, and finding alternate sources for about $2.5 million/year of their components. When I mentioned this to the sales rep, he acted like he didn't care or it wasn't important. **Oh, now that is interesting stuff. -- Trevor Wilson www.rageaudio.com.au |
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