EEVblog #808 - Fluke 196 Scopemeter Repair - Page 1
Forum section: electronics / general

author: EEVblog
author_rank: Unknown
timestamp: October 14, 2015, 11:13:03 am
content: Dave repairs a dumpster Fluke 196 Scopemeter handheld oscilloscope that has a faulty LCD screen.How to repair a faulty hot bar LCD screen flat flex cable connection.Service Manual with full schematics:http://assets.fluke.com/manuals/192_196_smeng0200.pdf

author: BravoV
author_rank: Super Contributor
timestamp: October 14, 2015, 11:52:55 am
content: There you go, expecting another big wave of price hike on used scopes with broken lcd.

author: max666
author_rank: Frequent Contributor
timestamp: October 14, 2015, 12:10:51 pm
content: So now with the LCD fixed, you could make use of the service manual by fixing the scope input, Dave.EEVblog #808 - Fluke 196 Scopemeter Repair - Part 2

author: EEVblog
author_rank: Unknown
timestamp: October 14, 2015, 12:11:32 pm
content: Quote from: BravoV on October 14, 2015, 11:52:55 amHoly crap, just checked, membrane keypad for $455!http://www.ebay.com.au/itm/NEW-FOR-Fluke-192-196-199-Membrane-Keypad-Replacement-523188-/331530524500?hash=item4d30c25754And as it turns out, this guy repairs this exact fault! Must be common as mud?http://www.ebay.com.au/itm/Fluke-192-196-199-Scopemeter-LCD-Display-Repair-/230424487426?hash=item35a65ea602

author: BravoV
author_rank: Super Contributor
timestamp: October 14, 2015, 12:14:54 pm
content: Quote from: EEVblog on October 14, 2015, 12:11:32 pmOnce he knew or watched your video, he will hate you, just look the number of repairs he sold.I guess, this is a good example where you've just made an enemy. LOL

author: EEVblog
author_rank: Unknown
timestamp: October 14, 2015, 12:17:17 pm
content: Quote from: BravoV on October 14, 2015, 12:14:54 pmOh wow, 56!Says he replaces something though. I don't suspect my repair will be very reliable, I don't trust that conductive adhesive, it came loose for a reason...

author: mux
author_rank: Regular Contributor
timestamp: October 14, 2015, 12:42:45 pm
content: Pretty much certain that scopemeterrepair.com uses NOS LCDs to replace the existing LCDs. This used to be big business back in the day with lots of standard hitachi graphic LCDs.You can't really justify the hours spent on such a thing if you can buy OTS identical LCD modules (and maybe an adapter board) for a couple bucks wholesale.

author: Wile E. Coyote
author_rank: Newbie
timestamp: October 14, 2015, 01:07:57 pm
content: We have the same Fluke 196 in our office. Your rants about Fluke's lack of LCD reparability & support bring back fond memories (Fluke stopped supporting & selling the LCD shortly after we purchased the 196). I think every tech here has had their hand at repairing it with various levels of success. The hot-bar never kept a good connection.Now we just keep our 196 around as a warning to other Fluke meters should they decide to develop faults. I don't believe any meter should suffer the same fate as our 196.Although I have to admit, when I saw that you had a repair video for the 196 (and when I peeked at the end of the video and saw the thumbs up), I was hoping you found a solution that we did not think of for a permanent repair! Nope - same Band-Aid repair.Love the videos & keep up the great work!-Mike AD0OY

author: bktemp
author_rank: Super Contributor
timestamp: October 14, 2015, 01:19:11 pm
content: When repairing hotbar connections, the pressure must be applied until the glue has cooled down.You can also use a soldering iron set to <200°C with a clean tip for repairing. But you still have the problem applying pressure until the glue has hardened again.VOGT was a German manufacturer of inductors and transformers. Now it is part of Sumida. Custom built transformers made by VOGT are quite common in all kind of products made in Europe.Hitachi merged with Mitsubishi and formed Renesas in 2003. That was the end of of Hitachi beeing the most common manufacturer of lcd controllers and drivers.

author: Fungus
author_rank: Super Contributor
timestamp: October 14, 2015, 02:12:38 pm
content: Quote from: bktemp on October 14, 2015, 01:19:11 pmThat's what I was thinking...I would have placed a bar of metal (old heatsink, whatever) across the strip using clamps then heat it up and let it cool before releasing.

author: han
author_rank: Frequent Contributor
timestamp: October 14, 2015, 02:23:42 pm
content: Using This one?

author: Fungus
author_rank: Super Contributor
timestamp: October 14, 2015, 02:37:49 pm
content: Quote from: han on October 14, 2015, 02:23:42 pmThat's perfect! I'll be opening up an eBay repair store in the next few minutes...

author: Ampere
author_rank: Regular Contributor
timestamp: October 14, 2015, 02:50:25 pm
content: Excellent repair, Dave.It's a shame that it's more of a meter than a scopemeter, though. Maybe that would make a good followup video?

author: AF6LJ
author_rank: Unknown
timestamp: October 14, 2015, 02:57:39 pm
content: Good go at it Dave.

author: Dave Turner
author_rank: Frequent Contributor
timestamp: October 14, 2015, 03:22:59 pm
content: I agree with Max66. Please finish the job. Get rid of the EEVBlog curse.

author: noidea
author_rank: Unknown
timestamp: October 14, 2015, 03:38:12 pm
content: Wow Dave what a coincidence, you post a thread on trying to fix a scopemeter and it's the same night that I decide to summon up the courage to take my 196C apart to try and fix it as well.The problem with mine seemed less drastic than yours the screen works great but it had recently stopped charging and would not operate from the mains adapter, yet still fired up with what was left in the battery (which is new). I must admit I was a bit more hesitant about taking it apart than you are but I fix air conditioners for a living and don't pull electronic stuff apart every day. So far the problem with mine appears minor, the power input connector is knackered as the centre pin has no continuity through the connector to where it goes down onto the PCB in the top corner.So if you decide not to go ahead with trying to fix the scope section and are going to dump it I'm in Oz too and would happily dispose of the main board for youI also found something really strange, it appears that the cooling fan on the back of the PCU unit has never been plugged inI guess I really should start a repair thread on my unit instead of taking yours up.Cheers

author: free_electron
author_rank: Super Contributor
timestamp: October 14, 2015, 03:42:20 pm
content: if the charger doesnt work check out the switching transistor v4102. they fry very easily ... small sot23-6 pin package. obsolete but can be replaced by a fdc666 if you snip off one of the pins. the original transistor has a unique pinout that nobody else uses.

author: Supercharged
author_rank: Regular Contributor
timestamp: October 14, 2015, 04:22:15 pm
content: Just a little aside: I think below that bodge cap there is a resistor

author: Tuomas
author_rank: Contributor
timestamp: October 14, 2015, 06:23:52 pm
content: The university where I studied had one lab with a bunch of those scope meters and every single one of them had those horizontal lines all over the display.Fluke refused to fix them since they were out of warranty. Apparently the lab doesn't buy Fluke equipment anymore.

author: AF6LJ
author_rank: Unknown
timestamp: October 14, 2015, 06:46:08 pm
content: Quote from: Tuomas on October 14, 2015, 06:23:52 pmThere was a number of displays that used similar technology that had the same reliability problems. A piece of amateur radio gear I own is notorious for the displays developing horizontal lines just after warranty.

author: krivx
author_rank: Frequent Contributor
timestamp: October 14, 2015, 07:38:52 pm
content: If anyone is interested, a much longer lasting method for these kind of repairs is to etch away the adhesive and some insulation and solder the cable in place.http://www.projectvb.com/displayfix.html#Solder

author: TheSteve
author_rank: Unknown
timestamp: October 14, 2015, 08:28:14 pm
content: Do the various chips that looked like they had a thin heatsink pad on them require heatsinks? Being at least one person has previously tried to fix it they may have removed the heatsinks. Or do the pads make contact with a metal shield when assembled?

author: envisionelec
author_rank: Frequent Contributor
timestamp: October 14, 2015, 08:37:31 pm
content: I actually own a hotbar press for the anisotropic adhesive that is used on these things.It is literally a PID controlled heating element and a machined copper shape attached to a press with a torque-reading gauge for an arm. It was $4000.

author: German_EE
author_rank: Super Contributor
timestamp: October 14, 2015, 08:57:19 pm
content: Quote from: AF6LJ on October 14, 2015, 06:46:08 pmLet me guess, an Icom IC-756 transceiver

author: Radio Tech
author_rank: Frequent Contributor
timestamp: October 14, 2015, 09:11:38 pm
content: Quote from: German_EE on October 14, 2015, 08:57:19 pmSame problem with the Kenwood VM-7. Think that model is correct.Good job Dave. Now fix the scope

author: AF6LJ
author_rank: Unknown
timestamp: October 14, 2015, 10:58:44 pm
content: Quote from: German_EE on October 14, 2015, 08:57:19 pmIndeed and now there is nobody making a replacment display module for the radio.Thankfully in 2011 I bought a module and replaced it.Not that great contrast is crap, it is the nature of the module.One of these days I hope to find something that woks better.https://forums.qrz.com/index.php?threads/ic-756-display-replacment.302777/

author: wblock
author_rank: Regular Contributor
timestamp: October 15, 2015, 01:42:35 am
content: That "anisotropic" glue is amazing stuff. Well, amazing that it works at all. Conductive only in the Z axis... but how does that work? Wikipedia says some of it is stuck together at room temperature, so at least those connectors do not rely on heat to make a chemical change. Maybe it's something that happens as it cures? Other web searching just pointed out that yes, it's only conductive in one dimension, but not really how it does that, or how it knows which dimension is which. A chemical change that goes from edge to edge and so completes in the thinnest dimension first, blocking the others?

author: steve30
author_rank: Frequent Contributor
timestamp: October 15, 2015, 02:11:12 am
content: Well done Dave. I expected you'd at least make an improvement with the display cable. I attempted to repair one of those cables once, and whilst I didn't fix it completely, I did at least make the display readable.

author: NiHaoMike
author_rank: Super Contributor
timestamp: October 15, 2015, 02:52:38 am
content: Quote from: AF6LJ on October 14, 2015, 06:46:08 pmI once had a tablet with a "static LCD" that failed with lines twice under warranty. The second time, I had them trade it for the version with a conventional LCD.

author: Rasz
author_rank: Super Contributor
timestamp: October 15, 2015, 03:27:06 am
content: Yay another win5.7" 320*240 is typical industrial parameters = very expensivebut someone dedicated could do a conversion to thishttp://andybrown.me.uk/2013/10/19/vivaz-u5-lcd/hitachi driver bus is slow and simple, pic32/stm32 could easily grab that and convert to another screen, or even stream directly over bt/wifi to a phone/tablet

author: Smokey
author_rank: Super Contributor
timestamp: October 15, 2015, 04:15:01 am
content: Quote from: Supercharged on October 14, 2015, 04:22:15 pmThat's what I was going to say.

author: Monittosan
author_rank: Regular Contributor
timestamp: October 15, 2015, 09:38:03 am
content: Its the same deal with the fluke 120 series except the flat bar is even harder to access.I had a go at repairing one nearly a year ago with a soldering iron and its still working fine. I did want a 196c - 199C but I guess thats not going to happen now DaveQuote from: Monittosan on November 05, 2014, 07:06:33 ambeforeAfter

author: PA4TIM
author_rank: Super Contributor
timestamp: October 15, 2015, 11:20:50 am
content: Nice video, I'm glad to know these strips are more or less repairable.I have a dead Fluke 192 from a customer here. But I'm stuck. I hoped to see/learn some troubleshoot techniques but the 192 differs a lot. Non the less it would be great to see a follow up video.The 192 has three Fluke Asics and one of them is a huge bga. The firmware and SRAM is on a piggy back and one of those bga's reacted on pressure so I reballed it. Now it charges, beeps when powered on, the 3 clocks do what they should do according the tests in the manual. And following the manual trouble shoot part and my measurements the problem seems to be missing or corrupt firmware and/or defective memory.The manual now wants software and an interface to check things.But these scopes are a pain in the ass because those asics work together. The psu ASIC fires some parts of the psu for charging and "booting" . That in turn starts the digital asic and that digital ASIC then starts the rest of the psu ASIC etc. (or something like that, it is resting for 2 months now, the owner try's to get the interface/software so I do this from memory) A bit a chicken and egg situation.For the electronics scopemeter-porn aficionado's, I repaired a Tektronix equivalent in the meantime. (pictures:http://schneiderelectronicsrepair.nl/?p=212)

author: gordo51
author_rank: Contributor
timestamp: October 15, 2015, 08:33:03 pm
content: Two successful repairs in a row. Dave is on a roll.I have an older 100MHz scopemeter that refuses to run on the battery even though I have two different fully charged batteries.The internal connections appear to be fine and I cannot see anything like a fuse so nothing obvious.Any ideas out there?

author: AF6LJ
author_rank: Unknown
timestamp: October 16, 2015, 12:44:31 am
content: Quote from: NiHaoMike on October 15, 2015, 02:52:38 amMy IC-756 was my first encounter with those displays, When I read about their high failure rate and started seeing the same display in point of sale terminals failing I was rather unhappy. There were a few other issues I had with the radio and after spending 2.2 K$ on the radio I was not happy. I know they have become more reliable but the way they are put together doesn't give me a lot of confidence.

author: mcleod
author_rank: Contributor
timestamp: October 16, 2015, 07:12:15 am
content: Quote from: TheSteve on October 14, 2015, 08:28:14 pmYes, they need heatsinks. There is a large sheet metal shield/heatsink that covers that section of the scope from the factory. It is not in the case, but a separate piece. Obviously, some clown lost it or was too lazy to replace it.There are also shields/heatsinks that cover the scope input sections and the meter section.

author: Assafl
author_rank: Frequent Contributor
timestamp: October 16, 2015, 08:07:48 pm
content: The heat sink is part of the shield cans. There should be an angled piece inside connected to the can that presses on the ASIC. Therefore the heat pad is required.If you do get a battery remember to charge it and use the scope meter at least on a semi weekly basis or the batteries die rather quickly.

author: memeruiz
author_rank: Contributor
timestamp: February 10, 2020, 03:30:39 am
content: Hi Dave,I don't know if you could finish fixing the Scope completely.A couple of things:1) Keyboard membrane fails a lot. Sometimes the scopes seem unresponsive, when in reality is the keyboard that is not working.I fixed this by using a fixed PCB instead of a membrane one:https://www.ebay.com/itm/Fluke-192-196-199-Scopemeter-Keypad-Contact-Board-Replaces-Foil/231220134535?hash=item35d5cb4287:g:u~0AAOxyOalTYqZ82) The sticky tapes that you found on the ICs are actually for connecting to the metal back of the scope. They come into contact when you rescrew the scope. It happened to me that the scope freezes if some of these ICs overheat. Check that. Or reapply heat transfer paste there. Those tapes looked toasted and old.What I want is to upgrade my old 196 scope with the newest firmware. Mine is so old that it can not be upgraded by the user according to fluke. Apparently the board must be modified. If you could take a detailed picture of the main board, both sides, that would be great to take a look into my scope and see if it is possible to upgrade at home.All the best!