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Electronics => Repair => Topic started by: hitecelec on November 09, 2019, 10:01:59 am

Title: Fluke 744 display
Post by: hitecelec on November 09, 2019, 10:01:59 am
hi

looking for the commercial part number for fluke LCD Display and service manual
picture attached

thanks in advance

Anand
Title: Re: Fluke 744 display
Post by: Black Phoenix on November 09, 2019, 01:19:44 pm
Directly from Fluke's calibration manual - LCD MODULE, 240X200 GRAPH TRANSMISSIVE - 602430.

https://dam-assets.fluke.com/s3fs-public/74x_____cmeng0200.pdf (https://dam-assets.fluke.com/s3fs-public/74x_____cmeng0200.pdf)

https://www.ebay.com/itm/for-multimeter-F-744-FLUKE744-FLUKE-744-LCD-screen/123686026086?hash=item1ccc42fb66:g:LLwAAOSw0dFchhuW (https://www.ebay.com/itm/for-multimeter-F-744-FLUKE744-FLUKE-744-LCD-screen/123686026086?hash=item1ccc42fb66:g:LLwAAOSw0dFchhuW)
Title: Re: Fluke 744 display
Post by: rvalente on November 09, 2019, 03:32:57 pm
The polarizer film went bad, its a characteristic of some vintagem LCDs from 90s, just replace both (easily found online).

Carefully disassemble the display, peel of the old polarizers
Clean the glue residue, try rubbing alcohol, then acetone and last gasoline
Make sure the screen is totally residue free, no oils or dirt
Play with the film to find the best contrast angle. Use a scalpel to cut the film, not a scissor (they crack the film)

That was my THS720P before:
(https://www.eevblog.com/forum/repair/tektronix-ths720p-bad-screen-lcd-lm32p10/?action=dlattach;attach=168119;image)
(https://www.eevblog.com/forum/repair/tektronix-ths720p-bad-screen-lcd-lm32p10/?action=dlattach;attach=168121;image)

And after replacing the polarizer. You can see I missed cleaning the backlight diffuser.
(https://www.eevblog.com/forum/testgear/tek-ths720a-portable-scope-teardowndiscussion/?action=dlattach;attach=852746;image)
Title: Re: Fluke 744 display
Post by: hitecelec on November 11, 2019, 06:20:32 am


hi

thanks for all the hints. Will try out and let you know