Why NOT to drop a Fluke 5200A AC Calibrator! - Page 1
Forum section: electronics / general

author: enut11
author_rank: Super Contributor
timestamp: October 19, 2020, 04:09:14 am
content: Who should we trust to ship our most valued metrology gear?EEVblog Forum member @wolfy007 was unfortunate enough to suffer damage to a pristine Fluke 5200A AC Calibrator, not once but twice!His words"Oh and a quick write up regarding the Fluke 5200A;I purchased the Fluke 5200A from Richard in Canberra, late 2019 via eBay. Richard advised I come by and pick it up. I told him I have had other equipment safely shipped from Canberra and if he could arrange shipping, which he did. When I got it, it was evident the solid box it was packed in had taken a couple of decent hits. Upon opening the box you could tell the Fluke had been very well packed but the unit was still damaged as you saw yourself. It had the a rattle of something loose inside but in my annoyed state I inattentively decided to try power it up. No sign of life, which upset me even more as the unit looked in very nice condition apart from its recent damage, especially considering its age. In a juvenile huff I set it aside and refused to look at it, imagining the worst horrors inside and deciding to leave it for much later to look at after my memory of it had abated. Obviously the subsequent equipment I purchased from him I personally collected, especially the 3458A and the 734A, 732A + 752A."I met @wolfy007 through an eBay sale and when I found out he had an AC Calibrator - dead or otherwise - it perked my interest. I had some AC meters that needed checking so I volunteered to fix it. When I went to get it, it took 2 people to lift it (24Kg) as it was built in the traditional Fluke way.

author: enut11
author_rank: Super Contributor
timestamp: October 19, 2020, 07:15:51 am
content: The Fluke 5200A AC Calibrator is a monster. Besides the 24Kg dead weight, it measures 43 cm wide, 18 cm high and 57 cm deep. This is not a normal desktop instrument!@CaptnYellowShirt posted a teardown and repair of a Fluke 5200A if you need more info.https://www.eevblog.com/forum/repair/fluke-5200a-ac-voltage-calibrator-teardown-and-repair/msg382484/#msg382484The pix below show the external and internal damage to @wolfy007 5200A. The rattle came from loose bits of motherboard sockets damaged when the calibrator was dropped.

author: alm
author_rank: Super Contributor
timestamp: October 19, 2020, 09:34:12 am
content: I have a 5200A on my repair pile that also had the bent handle and a bunch of the colored PCB mounting thingies broken, but no other signs of trauma. So these appear to be the first things to go. The motherboard sockets indicate more severe trauma, I think.Quite possibly the mounting bits got brittle over time. I was considering plastic welding them, but I have not looked at what type of plastic it is yet.

author: enut11
author_rank: Super Contributor
timestamp: October 19, 2020, 06:58:58 pm
content: Hi @almIt's the weight of the 5200 PCBs that contribute to the problem. Epoxy glue, especially the longer setting variety, should be good enough to secure the broken bits.enut11

author: enut11
author_rank: Super Contributor
timestamp: October 19, 2020, 07:07:03 pm
content: A few of the PCBs in the 5200 weigh several Kgs so a sudden jolt can cause significant damage.The power supply board assembly also has to bear the weight of a hefty transformer which can put a large load on the mother board slot.

author: srb1954
author_rank: Super Contributor
timestamp: October 19, 2020, 09:01:25 pm
content: Quote from: enut11 on October 19, 2020, 07:07:03 pmDid you receive the 5200A with the top shielding cover in place?This cover locates on the plastic pegs along the edges of the PCB and provides useful support of the heavy PCBs taking some of the strain off the edge connectors.

author: enut11
author_rank: Super Contributor
timestamp: October 19, 2020, 11:06:58 pm
content: Thanks. Yes @srb1954, the 5200 was complete as-received and I was just about to mention that.The top shield on the 5200 has a number of round holes that engage plastic 'pins' on the PCBs and provides a secure board locator.

author: enut11
author_rank: Super Contributor
timestamp: October 19, 2020, 11:22:44 pm
content: The impact(s), courtesy of the carrier, also damaged a number of the PCB top locators.

author: enut11
author_rank: Super Contributor
timestamp: October 20, 2020, 07:16:57 am
content: The main repair centered around fixing the two broken motherboard slots.First step was to epoxy glue the small bits of the edge connectors. Then, when the glue set, I fabricated two U-sections from Al sheet and glued these across the ends to reinforce them.Several broken and cracked PCB top locators were also epoxy glued.Lastly, the bent rear handle was gently straightened.After assembly, what a joy it was to hear the satisfying click of a relay and see the digit indicators light up.It works again!

author: alm
author_rank: Super Contributor
timestamp: October 20, 2020, 08:11:09 am
content: Nice work, congrats on fixing the damage so quickly! The repair on the sockets looks really neat.I'm glad the vibration testing by the carrier did not cause any additional damage, like ripping components of the boards.

author: wolfy007
author_rank: Frequent Contributor
timestamp: October 20, 2020, 11:40:07 pm
content: Quote from: alm on October 20, 2020, 08:11:09 amFloating components, thats part of the horror I thought would be inside...

author: enut11
author_rank: Super Contributor
timestamp: October 21, 2020, 01:29:12 am
content: Some more pix taken during the repair. Overall, the 5200 inside is crowded with hefty PCBs. The two smaller PCBs are part of the Power Supply.The Fluke 5200A is capable of generating accurate AC voltages from millivolts to 120 volts. Frequencies can range from a few Hz to over 1MHz.A remarkable piece of metrology gear well worth the effort to get it going again.enut11

author: wolfy007
author_rank: Frequent Contributor
timestamp: October 22, 2020, 12:14:11 pm
content: Most surprising part was that once re-assembled, it was actually looking like it might still be in cal. Initially tested with a Fluke 289, then plugged in a Siglent SDM3065X and finally enut11 plugged in one of his meters and all the numbers were looking good. Needs more testing, but after all the courier abuse then repairs, not sure how it was still putting out all the right numbers...Good design, lots of luck, good packing by the sender, providence, all of the above??? And thanks to enut11 for looking at it and making repairs, because I didnt want to...

author: srb1954
author_rank: Super Contributor
timestamp: October 23, 2020, 09:19:46 am
content: Quote from: wolfy007 on October 22, 2020, 12:14:11 pmSome of that old Fluke calibration gear seems to hold its calibration remarkably well over time. Fluke really knew how to make stable components.