RE: Unidentified chip -- Spoiler for HP 1260-0339
It doesn't even shunt across; it's just 16 pins in a DIL package floating? Strange. If it were a manufacturing test, one wouldn't expect it would show up in production machines? Yes. It is just 16 pins unconnected to each other. As I mentioned some messages ago it is used as a connector. It's soldered to the board so you can fit one of those 'IC Test Clips' on top and pick up 16 signals. I came across it on the test board for the HPIB interface for the HP9830 (where it has the HPIB signals wired to the pins). Another place you find it is on the test board for the HP Logic Comparator (you know, the tool that compares a reference IC signals with those on a chip on a PCB). The Logic Comparator has a test clip to fit onto the IC on the board under test in normal use, to test said Logic Compator there is a test board with a bit of logic wired to one of these empty 16 pin packages that you put the Logic Comparator test clip on. -tony
Re: Unidentified chip -- Spoiler for HP 1260-0339
Pin-out? Data sheet?
RE: Unidentified chip -- Spoiler for HP 1260-0339
And come to think of it, I bet those dummy chips were used for training people to hand stuff boards as well. The Amstrad PCW8256 (word processor) came with 256K of RAM but could be expanded to 512K essentially by adding another 8 41256 DRAM chips. Some companies in the UK sold the 9-chip kits used to expand PCs (with parity memory) for this, telling you to use the extra chip to practice with. However the HP package I mentioned is the only time I've seen one of these dummy chips used on a production board. -tony
Re: Unidentified chip -- Spoiler for HP 1260-0339
On 08/06/2015 02:25 PM, William Donzelli wrote: It could also be a chip used to test an auto-insertion machine or wave solder machine. If memory serves, they'll use correctly pinned but fake parts to test those processes before moving to the more expensive real thing. Yes, there were a few companies that made dummy chips for exactly that reason. These days, the robots are much better, so I doubt the practice of using dummy chips still exists. They definitely still exist. I doubt many people use them for PP testing, except maybe the people who MAKE the PP machines. But, larger outfits do extensive thermal profiles, cross-section microscopic examinations of solder joints and all sorts of exhaustive tests on soldering and other parts of the process. They use the dummy chips for testing the quality of these processes. They may run 25 boards with different thermal profiles to find out what gives the best soldering results. Jon
RE: Unidentified chip -- Spoiler for HP 1260-0339
Amazingly there is nothing inside that 16pin DIL package. No silicon chip, no thick-film resistor network, nothing. It is just a package with the pins. Are you sure? They might have gotten a really good deal on Well, I've not x-rayed one, but I could detect no conductivity or diode junctons between the pins. house-marked Signetics 25120 chips, with not all of the address lines bonded out. I've wondered why there wasn't a self-addressing serial version of the 25120, for First In Never Out stores. That would fit in a 16 pin package I think. -tony
Re: Unidentified chip -- Spoiler for HP 1260-0339
It could also be a chip used to test an auto-insertion machine or wave solder machine. If memory serves, they'll use correctly pinned but fake parts to test those processes before moving to the more expensive real thing. Yes, there were a few companies that made dummy chips for exactly that reason. These days, the robots are much better, so I doubt the practice of using dummy chips still exists. -- Will
Re: Unidentified chip -- Spoiler for HP 1260-0339
On Thu, 6 Aug 2015, Eric Smith wrote: On Thu, Aug 6, 2015 at 10:22 AM, tony duell a...@p850ug1.demon.co.uk wrote: Amazingly there is nothing inside that 16pin DIL package. No silicon chip, no thick-film resistor network, nothing. It is just a package with the pins. Are you sure? They might have gotten a really good deal on house-marked Signetics 25120 chips, with not all of the address lines bonded out. It could also be a chip used to test an auto-insertion machine or wave solder machine. If memory serves, they'll use correctly pinned but fake parts to test those processes before moving to the more expensive real thing. g. -- Proud owner of F-15C 80-0007 http://www.f15sim.com - The only one of its kind. http://www.diy-cockpits.org/coll - Go Collimated or Go Home. Some people collect things for a hobby. Geeks collect hobbies. ScarletDME - The red hot Data Management Environment A Multi-Value database for the masses, not the classes. http://scarlet.deltasoft.com - Get it _today_!
RE: Unidentified chip -- Spoiler for HP 1260-0339
As a total aside, on some HP boards there is a 16 pin DIL package with the part number 1260-0339. Any ideas what that chip is? What chip? Amazingly there is nothing inside that 16pin DIL package. No silicon chip, no thick-film resistor network, nothing. It is just a package with the pins. The purpose of it? It's a connector (!) to fit one of those IC test clips on to monitor various signals. -tony
