Spending the last 24+ years as an engineer on Enterprise systems from AT&T/Lucent Technologies/Avaya Communication, this is almost the exact same procedures that we used on the legacy PBX's from the AT&T/Lucent days. The circuit packs were the same dimensions, and even with similar TN identifiers. While even in a duplex system, most subscriber and trunk line cards could be done "hot", although you would still place them Out of Service from the console. The only time you powered down a shelf was when you were in the processor complex itself (and even then they had a few exceptions, particularly in a duplex system). Reportedly the AT&T 5ESS and the System 75/Definity G3 Enterprise platforms came from the same engineers, so they had a lot of these things in common. In all the years I've worked on them, I never had ESD destroy a card, and never bent a pin, so consider me lucky (and well versed in the handling procedures).
Nortel did the same thing. A Meridian SL-100/CS2100 is a rebadged DMS-100. AT&T sold a few 5ESS for large PBX deployments, where I used to work we had a 5ESS from the 1980s until the late-2000s. It used to provide ISDN data networking until Ethernet took over in the mid-90s.
@@straightpipediesel Re bent pins, was it just consumer systems that NT used card-edge on? I thought I remembered seeing most of the accessories for MDC using card-edge as well.
I wish I worked in that as well inside of a Windowless Building. I graduated last year with an IT Degree with a Minor in Criminal Justice (BA)… if only.
@@NortelGeek yeah, it must have just been the lower end. Small Meridian cards are of similar size/shape to DMS cards and use pin connectors very similar to the AT&T ones.
This, this is a major function of my Job today here in Washington. Replacing 5ESS packs. I recognize the TN335 LUCHBD pack he was replacing in a Line Unit.
Back in the electromechanical days of telephony the #1 ESS switch was looked at as a job threat. Our CO went from 45 technicians to 3 a few years after cutover to ESS. Two people were needed to run cross connect jumpers on the main frame.
I worked at Clevoh45 and Clevoh62. Better known as the Glenville and Cleveland Main CO. I started as an Apparatusman at the Glenville in 1968. In one year I was promoted to Central Office Technician. In the sixties the draft was taking young men for Vietnam, so I was promoted rapidly. I had already served in the Air Force.
@@ConnectionsMuseum I worked at the Clevoh45 and Clevoh62. Glenville and Cleveland Main. I started as an Apparatusman in 1968 and was promoted to Central Office Technician in one year. At the time the draft was taking most young men for Vietnam. I had already served in the Air Force.
I've never seen a 5E switch that lists the CLEI/HECI on the pack list. Just the apparatus code and location. This video is pretty old. No telling what generic they were running. I never knew what that RST/ROS switch was. Nobody ever uses that, including the center. ESD practices are always prudent but I rarely see anyone follow them in twenty years of central office work. 5E circuit packs are a lot more rugged and robust than this video would have you believe. We are now in the process of consolidating and ultimately removing the 5E switches. Consolidation because you can't get parts anymore. After removal, a huge roomful of 5E cabinets can be replaced with a few racks of GenBand gear about the size of a couple refrigerators. I like working on the 5E. I'll miss it when it is gone.
Wow these circuit packs are a lot like the Definity’s. I also see now why early definity circuit packs have a recess on the top cover, it is for that locking bar. I assume early system 75s had a locking bar like that.
The only thing I guessed that was done wrong on the first clip was he was not grounded against static discharge and he was touching the circuit board. I didn’t know anything about shutting down the unit after placing it out of service and checking to see if the system automatically placed the unit out of service. I never worked in an exchange so I had no idea but it all makes sense.
The person did not explain what TLP stood for. Trouble locating procedure. That would be the print out, that would be generated in the event of a failure of sorts. The TLP print out would give you a sequential number of circuit packs that are in question, and you would follow that procedure, starting with the most likely, to the least likely. That does not necessarily mean that you will replace the circuit pack that failed, it could be in the back of the frame or where the pins are somebody pressed up against it or a piece of loose material fell between and shorted something could be intermittent, or possibly a heart failure, that's where knowing how to use an oscilloscope came in, and running loops and setting up the proper sink to see what was going on, possibly in need of a microscope to see the pins the in the back plane side, to can see if a piece of loose welding material eventually broke loose and fell down, Etc.
I'm watching this again and a thought just crossed my mind--I realize that space was an issue and to ATT, every millimeter counted, however, why didn't they just put the packs that were most-replaced in plastic clamshells? As far as bent pins, they could have just used several rows of card-edge connectors (Wafa-jacks).
If its like the Enterprise systems, those packs went back for repair (each of those packs are thousands of dollars, so it was much more economical to return for repair compared to today's "throw away" technology - even today I still see used Enterprise System packs going for between $1,000 and $2,000 - that probably sold new for $6,000).
@@mwjones71 Indeed. Back in the 90s and before, it was not unusual to order new gear and it included a board that was "remanufactured". So you might order a minicomputer and a memory board came with a sticker stating it had been previously in use... same warranty and price as new. I think IBM did this a ton too in their midrange and mainframe business.
Why isn't he wearing, a ground wrist strap? When I work number four and number five SS, it was mandatory to wear a ground wrist strap when you remove any circuit pack. Touching the packs with your bare fingers, static electricity you could destroy a circuit pack that might be worth, $10,000 or more. At the time when I was working in both four and five ESS, if you did not use a wrist wrap, you could get as much as 3-day suspension without pay. I'm not sure if that was nationally, but in the New York metropolitan area, that was the rule.
I've worked in places (not phone switch places) where humidity was pretty high and nobody every saw an ESD problem. Of course, we still took precautions
I worked at Digital Equipment Corporation and ESD safe handling procedures were constantly drummed into our heads. I was surprised to see this instructional video showing no reguard for ESD handling of circuit cards. The man walks with a card in his hand touching his shirt. Puts paper next to removed circuit card. I don't see any ESD foot straps, wrist strap, ESD smock. I guess AT&T didn't see this as a problem. At DEC we were told that static discharge can zing a board and cause it to fail later if it doesn't cause it to fail outright.
@@ennexthefox I worked for AT&T formerly Western Electric on number for number 5 ESS you were required to wear a wrist strap at all times. No exceptions
