hatrick
Well-known member
I buy a fair amount of TTL chips from a local surplus electronics place. Some are pulls, and some have been stored for years in unknown conditions. They are cheap and convenient when I need something now, so I take my chances with them. When I work on something, there is always that thought that I may be replacing a bad chip with another bad chip, therefore wasting time chasing issues that don't exist. For this reason, I've always wanted an IC tester, but didn't want to lay out the cash for one, considering how many TTL chips you can buy for the cost of one.
I was browsing Ebay a couple weeks ago and came upon a strange looking Chinese device that claimed to be able to test 74xx chips plus some others for $39.99 & free shipping.
I was skeptical to say the least, but figured I've wasted money on stupider things, so I hit the "buy it now" button and waited.
It came from China in about a week, and I was fully expecting to point and laugh at myself when I realized I had gotten duped.
I ran down to the garage and put a 74ls138 chip in the socket and pushed the button. I'll be damned, the 7 segment LED flashed "7 - 4 - 1 - 3 - 8"
I tried a few more chips and it identified them as well. I then lifted a leg on a chip to see if it would report it as bad, and sure enough, it flashed "e - r - r" as it should for a bad chip.
I'm not sure how extensive of a "test" this thing is doing, but at the very least it would tell me if there is something catastrophically wrong inside a chip.
Interesting little device.
Here's a link to a quick video I took with a 74ls138 chip in the tester.
http://s1074.beta.photobucket.com/u...F-2E5395104D59-2160-000002AEE4C6E30F.mp4.html
I was browsing Ebay a couple weeks ago and came upon a strange looking Chinese device that claimed to be able to test 74xx chips plus some others for $39.99 & free shipping.
I was skeptical to say the least, but figured I've wasted money on stupider things, so I hit the "buy it now" button and waited.
It came from China in about a week, and I was fully expecting to point and laugh at myself when I realized I had gotten duped.
I ran down to the garage and put a 74ls138 chip in the socket and pushed the button. I'll be damned, the 7 segment LED flashed "7 - 4 - 1 - 3 - 8"
I tried a few more chips and it identified them as well. I then lifted a leg on a chip to see if it would report it as bad, and sure enough, it flashed "e - r - r" as it should for a bad chip.
I'm not sure how extensive of a "test" this thing is doing, but at the very least it would tell me if there is something catastrophically wrong inside a chip.
Interesting little device.
Here's a link to a quick video I took with a 74ls138 chip in the tester.
http://s1074.beta.photobucket.com/u...F-2E5395104D59-2160-000002AEE4C6E30F.mp4.html


