Reasonable IC test clips - Page 1
Forum section: electronics / beginners

author: msknight
author_rank: Regular Contributor
timestamp: December 31, 2021, 01:50:16 pm
content: I am troubleshooting a BBC B Micro and have a CY7C68013A board to use for logic testing.I have been told of IC clips that can go onto chips to save messing around with individual probes. A look at the 3M ones people recommend is a fair chunk of money, and the 40 pin version (which I would use for the 6502 processor and a few other chips) is discontinued.If people have advice that can bridge that gap between cost and reliability, I'd be grateful. I'd be looking for various pins, 28 and 40 would probably be the most common I would need to use.I'm located in the UK.

author: rob77
author_rank: Super Contributor
timestamp: December 31, 2021, 02:04:53 pm
content: cheapest and reliable enough is to dremel out the guts of an IC in the same size DIP package and solder some wires (great opportunity for failed ICs to be re-used) .. then you piggyback the IC on the board with the contraption you created

author: msknight
author_rank: Regular Contributor
timestamp: December 31, 2021, 02:59:42 pm
content: That's an interesting idea. Never thought of that.There was another post in the thread as well, but it vanished. I think I thanked the poster, or did I hit a wrong button?

author: Martin Miranda
author_rank: Regular Contributor
timestamp: December 31, 2021, 03:03:18 pm
content: i have a bad reading comprehension. hahaha. sorry. i deleted my previous post.

author: Ian.M
author_rank: Super Contributor
timestamp: December 31, 2021, 03:37:31 pm
content: You can still get DIP test clips for up to 64 pin packages:https://www.warwickts.com/95/DILDIP-IC-Test-ClipsThey are most useful when working on a board with soldered in DIP/DIL ICs making it difficult to use mini-grabbers, or if the ICs in question are rare and fragile so you don't want to risk removing them from their sockets to insert a breakout board in between them and their sockets.DIP test clips can generally be used with one pin extra overhanging at each end, so can fit a chip up to four pins smaller, so you don't need *EVERY* size clip. A 'beeb' has a lot of TTL logic so if you go down the clips road, you'll probably want a 16 pin clip for 14 and 16 pin logic chips, a 20 pin clip for the octal buffers and a 28 pin clip for RAM ROM and various peripheral chips in 24 and 28 pin 0.6" DIP packages, as well as the 40 pin clip for the CPU and other large peripheral chips. It does have one DIP-8 chip but its only a LM386N audio amp for the speaker so you can skip that size clip.

author: msknight
author_rank: Regular Contributor
timestamp: December 31, 2021, 03:46:01 pm
content: You know the BBC B well :-)Even with just the 16, 20, 28 and 40 that's still coming in at over £100 before VAT and delivery. That's why I was hoping to reduce the price a bit. At least those are AP, which I believe are quality. If push comes to shove, I'll have to pony up, but the amount of times I'll use these, it's a fair chunk of cash as a hobyist.

author: Ian.M
author_rank: Super Contributor
timestamp: December 31, 2021, 03:57:49 pm
content: Start with the 16 and 20 pin sizes which gives you access to most of the soldered chips.For access to the big socketed chips on the cheap, you can make a breakout board by soldering a socket to a piece of veroboard (with obvious track cuts), in between two rows of 0.1" pitch SIL square pin headers, and also soldering a 0.6" wide DIL flat pin header to the underside, pins out. Don't use a turned pin header as the 'beeb' used leaf spring DIP sockets which will become unreliable if you stretch their contact springs by inserting the thicker pins of a turned pin header.

author: rstofer
author_rank: Super Contributor
timestamp: December 31, 2021, 04:39:46 pm
content: Quote from: msknight on December 31, 2021, 03:46:01 pmDo the job properly and don't risk damaging irreplaceable parts. Sure, it costs money - everything costs money. Over the years, I have accumulated a complete set of test clips for DIP packages. I doubt that I could find them after a couple of moves.

author: msknight
author_rank: Regular Contributor
timestamp: December 31, 2021, 05:01:56 pm
content: Messages received and understood.I've found a listing on ebay in the US with a collection of used 3M test clips. I'm going to take a chance on that and hope they get here intact.When I have to work on a chip, I'm replacing the dual leaf sockets with turned pin... in a number of cases I have to anyway as the BeeBoop eeprom chips and the RetroClinic 1770 boards come with turned pin pins which don't sit too well in dual leaf - and I've caused a chunk of damage as the board is so old that I've brought up some traces in the course of working on it... particularly the blue sockets where both sides of the leaf are fed through the holes. There is discussion about the new issue 7 board being made and that's going to be interesting -https://twitter.com/PeepoUK/status/1475209907205021702- as the whole board can be fitted out with turned pin sockets and breathe new life into the system... but... yeah...OK ... message received... some things shouldn't be done on the cheap.

author: Alex Eisenhut
author_rank: Super Contributor
timestamp: December 31, 2021, 06:17:02 pm
content: Depends what you mean by reasonable, and if you want to use a scope or logic analyzer.The HP 10033 miniature scope probe has this plastic doohickey that secures the probe to a single pin of a .300 wide DIP package.https://www.ebay.com/p/1522798347Then there's the Micrograbbers for logic analyzers.https://www.ebay.com/itm/264961302910These interface to the standard "Dupont" style pin for logic analyzers, but you can just hook the wire to a scope probe too if you accept the extra distortion.

author: msknight
author_rank: Regular Contributor
timestamp: December 31, 2021, 07:15:49 pm
content: Those are what Martin pointed me to in an earlier post, but what I'm looking to emulate is a, "clamp," like device which covers the whole chip and each point presents at the top as a pin that a dupont cable can be plugged on to. Quite a neat thing which I didn't know actually existed until this morning, but as Ian has pointed to... aren't cheap.

author: james_s
author_rank: Super Contributor
timestamp: December 31, 2021, 07:39:39 pm
content: I've had pretty good luck buying used 3M test clips, and Pomona makes a quality product too. In a pinch even the knockoff clips from China aren't too bad, at least the couple of them I have work fine.

author: Alex Eisenhut
author_rank: Super Contributor
timestamp: December 31, 2021, 07:47:25 pm
content: Oh yes, that exists, kinda.https://partsmine.com/test-and-measurement/hp/hewlett-packard-vintage-ic-test-clip-m21065I've seen those but they were part of an entire system, not sure what those pins actually plug to. But hey, just jam whatever fits and see!