New Keithley DMM6500 and now DAQ6510

[Hydron]

I wonder if the better screen is an off-the-shelf part that can be retrofitted?

0x2102 - if you're willing to open up the "good" unit to the point where you can see the details of the panel then that might shed some light on it? You can read some writing on the FFC on mine (poor viewing angle panel) with just the lid off, but I'm not sure that includes the required info - will do some googling.

[Caliaxy]

I can definitely confirm that there are two different type of displays for the DMM6500.

The top unit has a calibration date of 3/2023 (display not as crisp, viewing angle limited) and the bottom unit 5/2023 (display sharp, no issues with viewing angle).

Unfair comparison. The upper display still has the lousy protecting film on it, the lower one doesn’t seem to have it. I would be shocked if removing it doesn’t improve the viewing experience

[Pinörkel]

Unfair comparison. The upper display still has the lousy protecting film on it, the lower one doesn’t seem to have it. I would be shocked if removing it doesn’t improve the viewing experience

As I had of course tested on my device, the protective film has no significant influence on the poor contrast or the screen doubling. It only adds environmental reflections. You can clearly see that in 0x2102's photos, where the settings menu area between the buttons is nearly black on the lower display(as it would be on the upper one when viewed from straight on) and medium gray in the upper one. This does not happen to the 100% black area around the voltage readout value, which clearly hints to a display tech contrast issue.

[Caliaxy]

You can clearly see that in 0x2102's photos, where the settings menu area between the buttons is nearly black on the lower display(as it would be on the upper one when viewed from straight on) and medium gray in the upper one. This does not happen to the 100% black area around the voltage readout value, which clearly hints to a display tech contrast issue.

I see, thank you… Also, have you tried adjusting the brightness setting (page 2-6 in the manual) to bring the dark background closer to black?

[Pinörkel]

I see, thank you… Also, have you tried adjusting the brightness setting (page 2-6 in the manual) to bring the dark background closer to black?

Since this only regulates the backlight brightness, it naturally cannot mitigate angle dependent loss of contrast or screen doubling. The strength of the issue scales with backlight brightness, so it remains at the same relative strength to the black value of the display.

[Caliaxy]

I see, thank you… Also, have you tried adjusting the brightness setting (page 2-6 in the manual) to bring the dark background closer to black?

Since this only regulates the backlight brightness, it naturally cannot mitigate angle dependent loss of contrast or screen doubling. The strength of the issue scales with backlight brightness, so it remains at the same relative strength to the black value of the display.

Well, on my DMM6550, adjusting the brightness seems to change a bit the contrast as well (black stays black at both extreme brightness settings, greys get darker at one end and brighter at the other end) - that's why I asked. Not sure in what extent it changes the contrast while viewing from an extreme angle though, if this is the issue the bothers you.

Haven't noticed any doubling...

[Hydron]

If you cannot see any doubling then you may already have an improved screen. This was a known issue (acknowledged by Keithley) at certain vertical viewing angles and is fairly obvious.

If you're game to take the lid off then you may be able to confirm by taking a pic of the display FFC where it peaks above the analogue board.

[0x2102]

I cannot see any doubling on any of my screens. The biggest difference between them:

1.) Contrast
2.) Viewing angle (one is worse when looking from above / other angle seemed to be fine)
3.) White balance (one is warm (bit yellow'ish and the other is colder (blue)

The one I prefer has a bit better contrast, viewing angle good from all side with a slight warm white balance. Part# ATM0500D27B1-CTN3 (seems to be an IPS panel)

The other one is Part# ATM0500D19F-CTN3 (TN panel)

[ArdWar]

Of course D27 is much nicer, it's an IPS panel. D19 on the other hand is TN panel.

[Hydron]

Thanks for the info, and it appears that the text on the FFC is sadly not relevant shows the D19 vs D27 type. Mine is D19 

Looks like digikey has the nice one, assuming the trailing N3 in the part number isn't relevant. They clearly can't ship to the UK though, you can only find in on the US site, and it's a bit spendy at 70 bucks.

[Pinörkel]

Indeed, this explains the issues: TN-panel and viewing angle down 50°.
http://www.zettlercn.com/products/displays/tft-modules/atm0500d19-ctn-detail-id_m00_164.html
http://www.zettlercn.com/products/displays/tft-modules/atm0500d27-ct-detail-id_m01_186.html

Unfortunately there does not seem to be an easy source for the touch variant atm0500d27-ct. Most sources like digikey only seem to have the non-touch variant.

[Hydron]

https://www.digikey.com/en/products/detail/az-displays/atm0500d27-ct/13236094

I assume .de is blocked access to the part like .co.uk is

Edit: damn, need the B-CT variant which is not stocked (600 vs 350cd/m2)

[Hydron]

Quick update - I just checked another DMM with a factory cal date of 22/6/2023, and it has a marking of "FPC0500D27B1" on the FPC leading to the display assembly, i.e. it also has the better display fitted.

It's hard to tell how much better this display is as the meter is in an extremely bright room, but it doesn't seem to show the "doubling" seen on the older part.

I'm gonna have a poke around digikey etc looking for easier-to-source compatible displays (need to get a compatible touch controller as well as a bright IPS panel), will post again if I find anything promising.

Edit: swapped the panels and the old meter is happy driving the new panel (I assume the reverse is true, will test tomorrow). Also noticed that while digikey doesn't have the D27B-CT SKU, they do have the D27K-CT, which is a panel rated for a higher LED current (and proportionately higher brightness). If the LED drive is a simple current limited supply then this might be the easiest drop-in replacement, with the caveat that we don't know if D27B1-CTN3 (what's on the sticker in 0x2102's post) is the same as D27(B/K)-CT (what comes up on the web/digikey). 73 bucks though! https://www.digikey.com/en/products/detail/az-displays/ATM0500D27K-CT/12168275

[0x2102]

@Hydron: maybe something to watch out for is that D19/D27B's background color is white vs the D27K's background color is black.

[Hydron]

Slightly confused here - are you talking about "Display mode", which is normally black on all D27 SKUs and normally white on D19? That's expected due to TN vs IPS. Or is there a difference within the D27 options that I missed?

[0x2102]

Never mind, I was slightly confused ;-)

Yeah, I was referring to the "display mode" but that makes sense TN vs IPS.

[Hydron]

OK so just confirmed that the D19F-CT3 (TN) and D27B1-CTN3 (IPS) are cross compatible both ways between older and newer DMMs (at least when you clip in the touchscreen controller FFC properly... )

I think I'll leave further investigations to others, though if I do end up grabbing a screen next time I'm in the states I'll report back.

[Hexley]

There is a firmware update available for the DMM6500. No new features, but a bug fix.
The version is 1.7.14j.
Details at https://www.tek.com/en/support/software/firmware/model-dmm6500-firmware-revision-1714-and-release-notes .