Author Topic: Recovery of an old Fluke 8020a with a bad LCD (Read 70798 times)

lowimpedance · « **on:** January 21, 2011, 01:41:31 am »

Hi
This is my first attempt at posting so I hope the pictures attach properly.

Just thought some may be interested in my rebuild of the LCD display on an old Fluke 8020a handheld meter.
What I did was to buy a 3.5 digit lcd (cheap) with through hole pins and then modify the plastic mount for the
old display so the new one would fit nicely and the slide in cover would keep it in place.
Next for the fun bit was to use wire wrap wire to connect the new LCD to the pcb pads where the old 'Zebra strip' was.
one of the photos shows clearly the old LCD module with the classic leaching of the older Flukes, making them totally
unusable.
The calibration is in spec. and has been checked on a calibrator at work.
Some may ask why bother, the answer is because I hate to see a good meter end up in landfill and I got a fully functional
meter to add to the collection.
cheers
LowZ

Kiriakos-GR · « **Reply #1 on:** January 21, 2011, 02:10:53 am »

Great job ...

I bet that you will enjoy this link too.

https://www.eevblog.com/forum/index.php?topic=718.0

Welcome in the forum John ..

Excavatoree · « **Reply #2 on:** January 21, 2011, 03:38:25 am »

Great idea. These old meters (8020, 8021, 8022, ....) will last a while, but their weakness is the LCD, and stock LCDs and zebra strips are difficult if not impossible to find. (and some are selling them for ridiculous prices.)

I'm a big fan of these meters, and also the idea of keeping something working.

saturation · « **Reply #3 on:** January 21, 2011, 11:22:39 am »

Great job! That series put Fluke on the map, one of the first most popular DMMs.

~~http://support.fluke.com/SW-Common/SW-Find_It.asp~~

http://www.fluke.com/fluke/usen/community/fluke-news-plus/articlecategories/rd/a+little+history.htm

ElektroQuark · « **Reply #4 on:** January 21, 2011, 11:36:53 am »

Quote from: saturation on January 21, 2011, 11:22:39 am

http://support.fluke.com/SW-Common/SW-Find_It.asp

FLUKE says:

"Digital Library Fulfillment Center

# We are sorry, but the link provided to you to access this information is not valid.
# An automatic notification message detailing this problem was sent to the site administrator.
# Invalid Locator Format 4 - Invalid Document Number"

saturation · « **Reply #5 on:** January 21, 2011, 12:47:26 pm »

Sorry, try this:

http://support.fluke.com/find_it.asp?Document=2386856

If it doesn't work, the main page of the article, the link is at the bottom. The article is a pdf file.

http://www.fluke.com/fluke/usen/community/fluke-news-plus/articlecategories/rd/a+little+history.htm

Quote from: EdoNork on January 21, 2011, 11:36:53 am

Quote from: saturation on January 21, 2011, 11:22:39 am
http://support.fluke.com/SW-Common/SW-Find_It.asp

FLUKE says:

"Digital Library Fulfillment Center

# We are sorry, but the link provided to you to access this information is not valid.
# An automatic notification message detailing this problem was sent to the site administrator.
# Invalid Locator Format 4 - Invalid Document Number"

Excavatoree · « **Reply #6 on:** January 21, 2011, 03:43:32 pm »

Sorry for the intrusion, but can you give us the source and part number of the replacement display?

Kiriakos-GR · « **Reply #7 on:** January 21, 2011, 03:53:19 pm »

Quote from: Excavatoree on January 21, 2011, 03:43:32 pm

Sorry for the intrusion, but can you give us the source and part number of the replacement display?

Yes I am second in the line for this request ..

( it will be nice to know just in case that another similar needs to be rescued )

And also the cross connection schematic !! ( if possible )

About the tiny small cables as bridges , they can be found easily , inside of USB cables ..

Ernie Milko · « **Reply #8 on:** January 22, 2011, 10:08:57 am »

Excellent work. These are very good meters.
Did you manage to incorporate the low-batt flag?

Vyper · « **Reply #9 on:** January 22, 2011, 06:58:14 pm »

haha..I have one of those in the lab! It was/is a very good dmm. I rather liked them, I think they were manual ranging though. But good meters. Good luck sounds like a fun project. Think Ill get mine out of storage and see if it still works

Kiriakos-GR · « **Reply #10 on:** January 23, 2011, 01:48:39 am »

Quote from: Ernie Milko on January 22, 2011, 10:08:57 am

Did you manage to incorporate the low-batt flag?

That's interesting , in such repairs , no one can do that ,
because there is no spare digits on the " generic displays ".

Only the genuine Fluke displays haves this "extra" ability.

lowimpedance · « **Reply #11 on:** January 24, 2011, 12:05:28 am »

]Hi Kiriakos
Nice thread on the 8010, 12, and 50. I have all these meters too. Excellent meters for small money IF you can get one with a good LCD. I have done a similar replacement job on my 8012 (bit more involved mechanically). Still economic with a 3.5 digit
Replacing a 4.5 digit LCD though you might be better of contacting Fluke, but then you would be better of buying a new meter.
~~Interesting to note that both the 8020a and the 8010 and 8012 use the old ICL 7106 as the lcd driver/ converter disquised by a Fluke P/N.~~
EDIT: this turns out to be not the case as noted in the excellent thread 'OLD Fluke Multimeters', from DrTaylor of Fluke 8060a fame. The ICL7106 has some important range switching omitted.

Hi Ernie
Yes I have been able to include the low BATT symbol since it was part of the LCD I used as a replacement. I have also checked it works by running the meter from a bench supply.

cheers
LowZ

ps will get the hang of this forum stuff with using the quotes and other tools etc as time goes on but was not confident yet in case I look like a total nooby

Kiriakos-GR · « **Reply #12 on:** January 24, 2011, 05:11:30 am »

John do you have any part number about the display that you had use ?
Or info about the source of where did you got it ? price etc..

As you can see , in this place we share anything , except of our wife's ..

lowimpedance · « **Reply #13 on:** January 24, 2011, 05:55:16 am »

Hi Kiriakos
If you need to go down this path of repair then any reflective type 3.5 digit + LoBatt lcd from RS Components or Element14 will do.
For example the RS part number 215 6436 (Clover display or Varitronix). price around $10 Aust.
The lcd for the 8050a would be too difficult with its extra custom annunciators to replace easily.
On a slightly different note with the handheld 4.5 digit version the 8062a if you come accross one of these cheap beware that its possible the minature electrolytics which the meter has a good number on its pcb are prone to leaking and causing considerable damage and possibly the death of the meter (speaking from experience).

Cheers
LowZ

Kiriakos-GR · « **Reply #14 on:** January 24, 2011, 06:50:19 am »

Thanks for the tip

link: http://uk.rs-online.com/web/search/searchBrowseAction.html?method=getProduct&R=2156436

Excavatoree · « **Reply #15 on:** January 24, 2011, 01:16:25 pm »

Thanks from me as well.

Ernie Milko · « **Reply #16 on:** January 24, 2011, 02:34:49 pm »

Thanks a lot for the inspiration; I'll have to give this a go on mine when I get the chance.

Vyper · « **Reply #17 on:** January 24, 2011, 05:05:09 pm »

I found my old meter. I thought it was a 8020a but its a 8060A. It still works good! along with my simpson 376 RT AC VM.

Vyper · « **Reply #18 on:** January 24, 2011, 05:09:11 pm »

here is a photo!

Quote from: Vyper on January 24, 2011, 05:05:09 pm

I found my old meter. I thought it was a 8020a but its a 8060A. It still works good! along with my simpson 376 RT AC VM.

saturation · « **Reply #19 on:** January 24, 2011, 05:20:26 pm »

Some of your photos are a trip down memory lane, I see an older model orange colored logo B&K Precision function generator, it looks like it has missing knobs. 1 newer blue colored B&K sweep function generator is also in the photo.

Vyper · « **Reply #20 on:** January 24, 2011, 06:40:35 pm »

You're right Saturation! Its an older BK precision/Dynascan 3020 SFG. Range knobe is missing but it works great. My newer one is a BK 4017 SFG, Fluke 45 dual display bench dmm, a EZ-FC-7150 freq. counter. I have a BK 1590A analog scope I still use

A BK 1715 DC PS, BK1686 DC PS, BK1653A AC PS, BK1604A Isolated AC PS, Heath Zenith SP-2717 HV PS, BK 1650 Tri output PS, BK1805 freq. counter, Advantest R3267 Spectrum Analyzer, Etc, Etc,.. These are my personal tools. The agency I work for has equipment you wouldnt BELIEVE That I use in the lab. Oh well...One can only dream of owning them

Like a Rohde&Schwarz R&S®FSU67 and a
Rohde&Schwarz SMR40 Microwave Signal Generators to name a few. But WAY outta my pay rang or anyone elses I can think of!!

saturation · « **Reply #21 on:** January 24, 2011, 08:38:20 pm »

The good news with that is you can test your home gear against stuff you have at work, its surprising how much lower cost gear can perform very well in select or many areas, but you need excellent test equipment to reference your home gear against.

Quote from: Vyper on January 24, 2011, 06:40:35 pm

You're right Saturation! Its an older BK precision/Dynascan 3020 SFG. Range knobe is missing but it works great. My newer one is a BK 4017 SFG, Fluke 45 dual display bench dmm, a EZ-FC-7150 freq. counter. I have a BK 1590A analog scope I still use
A BK 1715 DC PS, BK1686 DC PS, BK1653A AC PS, BK1604A Isolated AC PS, Heath Zenith SP-2717 HV PS, BK 1650 Tri output PS, BK1805 freq. counter, Advantest R3267 Spectrum Analyzer, Etc, Etc,.. These are my personal tools. The agency I work for has equipment you wouldnt BELIEVE That I use in the lab. Oh well...One can only dream of owning them Like a Rohde&Schwarz R&S®FSU67 and a
Rohde&Schwarz SMR40 Microwave Signal Generators to name a few. But WAY outta my pay rang or anyone elses I can think of!!

sonicj · « **Reply #22 on:** January 26, 2011, 05:10:14 pm »

murdered out 77/bn mod

Excavatoree · « **Reply #23 on:** January 26, 2011, 05:28:21 pm »

Ok, I have to know how you did that. I know it has to do with reversing the polarization, but I'm guessing you'd have to either use a different LCD or somehow remove the polarizer on the stock LCD and add another that is rotated 90 degrees.

sonicj · « **Reply #24 on:** January 26, 2011, 06:10:48 pm »

-remove the front polarizer. i used alcohol and fresh razor blade. it takes some effort to remove w/o damaging the plastic polarizer.
-remove adhesive from polarizer. this step is the hardest. the glue/epoxy is pretty tenacious. i scratched the polarizer pretty good and sorta melted it trying different solvents. denatured alcohol and patience worked best. replacement polarizing film is available online if you screw up.
-clean the glass. remove any excess adhesive. wipe your dirty paw prints off everything. gloves and kimwipes at this point. i didn't spend as much time on prep as i should have as this is a dead meter and i was just experimenting.
-replace the front polarizer inverted. i used some polyamide tape to hold it down for the photo, but if i were doing it on a working meter i'd likely use a optical grade epoxy like norland 72 or similar.
-done.

i just ordered a swatchbook from rosco.... i want to play with some colors next! link


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Author Topic: Recovery of an old Fluke 8020a with a bad LCD (Read 70798 times)

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