A Fluke 77 made on a Friday afternoon !. - Page 1
Forum section: electronics / testgear

author: lowimpedance
author_rank: Super Contributor
timestamp: September 15, 2015, 05:48:12 am
content: Purchased an old Fluke 77 for sentimental reasons through the usual online 'place'. Listed as tested and working, ie showed a pic connected to a 9 volt battery.Anyway of course it did not function normaly when received so opening up showed some horrible gunk around the input jacks and some corrsion. A good IPA clean or two later and some deoxit on the input terminals and all was good again for the old timer.BUT while it was appart I noticed some rather unusual component placement done at manufacture. See the pics. for the best explanation.Much comment is made about poor PCB assembly of products and even other upmarket DMMs in the past, and here is a pretty good example of one slipping through visual QC all those years ago.AND has it mattered since then for this unit, not one bit and after the cleanup it was still in spec. no tweak needed and back in service.note: 10V ref and 87V verified at work, so trust me the 77 was in spec.

author: retiredcaps
author_rank: Super Contributor
timestamp: September 15, 2015, 05:55:38 am
content: Quote from: lowimpedance on September 15, 2015, 05:48:12 amThanks for sharing the picture.

author: ModemHead
author_rank: Frequent Contributor
timestamp: September 15, 2015, 12:17:02 pm
content: Oops. Looks a bit starved for solder as well, I don't see any fillets.

author: oldway
author_rank: Super Contributor
timestamp: September 15, 2015, 12:59:29 pm
content: Excuse me, but I find it necessary to have the particularly twisted mind to come and to do quality control on a meter which worked perfectly for over 25 years and which will function even more other 25 years without any problem.

author: linux-works
author_rank: Super Contributor
timestamp: September 15, 2015, 01:28:41 pm
content: your fluke had the POPC feature, I see (physical offset phase compensation) !lol

author: quantalume
author_rank: Unknown
timestamp: September 15, 2015, 02:46:08 pm
content: I really like those older, trim, 70-series meters, before they bastardized the design with that ugly yellow surround case. In fact, I will not buy a test instrument that has a yellow case.

author: mos6502
author_rank: Frequent Contributor
timestamp: September 15, 2015, 03:02:26 pm
content: Just don't show the 250V glass fuse they used in this thing, or Dave will burst a blood vesselBut hey, at least they give you a spare.

author: commongrounder
author_rank: Frequent Contributor
timestamp: September 15, 2015, 07:55:16 pm
content: It's a good thing the board is solder starved. There would have been bridges on almost every pin on those chips if there had been more.

author: DanielS
author_rank: Frequent Contributor
timestamp: September 15, 2015, 08:38:51 pm
content: Quote from: commongrounder on September 15, 2015, 07:55:16 pmIf there had been more solder, surface tension might have pulled the chip into alignment.

author: lowimpedance
author_rank: Super Contributor
timestamp: September 15, 2015, 11:38:30 pm
content: Quote from: oldway on September 15, 2015, 12:59:29 pmUmm dude , re read to the end where I said "had it matterred, not one bit" , how ever do you seriously think this construction is acceptable ??.

author: madalf71
author_rank: Contributor
timestamp: September 16, 2015, 02:06:30 am
content: Looks like mine was made on a Monday, little bit offset on one side.

author: retiredcaps
author_rank: Super Contributor
timestamp: September 16, 2015, 06:17:41 am
content: With respect to U1, Excavatoree, our resident Fluke expert, mentionedQuote from: Excavatoree on August 28, 2014, 08:43:23 pmhttps://www.eevblog.com/forum/testgear/fluke-77-strange-demise/15/Since the main IC is dated 1984, maybe this Friday one, is one that Excavatoree has seen?

author: lowimpedance
author_rank: Super Contributor
timestamp: September 16, 2015, 11:46:38 am
content: Quote from: retiredcaps on September 16, 2015, 06:17:41 amInteresting, perhaps quite a few more 'Friday ones' exist !.My meter has the alignment issue on both ICs and yet still functions no problems.To note I did give the PCB a little bit of twist to see if the soldering or apparent lack off was an issue. It would seem to be okay and I think I will leave it be (if it ain't broke why fix it).