My Experience with the Panasonic DP-UB420
I bought my Panasonic UB420 in Nov. 2019 on sale for $149.99 ($100 off) at a local store.
The UB420 supports HDR10 and HDR-10+ (no Dolby Vision support), and has the same "HDR Optimizer" as the more expensive DP-UB820 model. The HDR Optimizer is a plus for OLED TVs, lower nit LCD TVs or Projector owners, and it has many video adjustment options (including HDR to SDR/BT.2020 conversion) you may find useful. (The UB420 can't display HDR metadata info - the UB820 & UB9000 can, by pressing the Playback Info button twice.) If you don't need Dolby Vision support (and especially if your TV supports HDR-10+), I think the UB420 is one of the better 4K/UHD disc players at the $149.99 sale price.
(A 50 page Panasonic DP-UB420 User Manual (PDF) is here.)

4K/UHD 100GB Disc Playback:
I've tested several 100 GB (triple layer) UHD movie discs that had freezing/skipping issues with my LG 870 and Sony X800 on 2 different UB420 samples (Aug & Sept. 2019 build dates, shipped with firmware 1.60, later updated) - both played those discs without problems, but YMMV. As I always do when having problems with 4K/UHD discs, I cleaned them with Dawn soap and warm water, but it only helped a bit with MI Fallout - instead of freezing it would pause/slow-motion through that point with the Sony & LG Players. (Note: May 2020 LG Firmware updates helped - the UBKM9, UBK90, UP970 & UBK80, UP875, UP870 players had updated player firmware and servo (drive) firmware. (Newer June 2022 UBKM9, UBK90, UP970 & UBK80, UP875, UP870 firmware updates now.) And Sony updated firmware in late Aug. 2021 & late May 2022 for X700, X800M2, X1100ES & X800, X1000ES models. Details are in the links.)

Update: After over 2 years of use with my UB420 I've had no disc freezes or problems with any cleaned, unscratched discs - including many 100GB UHD Movies. No regrets buying it for $149.99. (The lowest I've seen the UB820 on sale is $349.99 - $150 off MSRP. Typical sale price is $100 off.)

HDR to SDR Conversion Option:
For Projectors or TVs that support Wide Color Gamut but not HDR (or do HDR poorly), there's an option to output HDR as SDR BT.2020 Wide color Gamut, (or BT.709) in the Player's HDMI -> Advanced Settings. (HDR to SDR conversion can use the HDR Optimizer adjustments, including Dynamic Range conversion adjustment slider to increase/decrease brightness.)

Subtitle Brightness Adjustment:
The UB420 (and UB820/UB9000) has several Subtitle options, including not only position (which some other players also have), but also Subtitle Luminance (brightness), which no other brand of player I've owned has. I wish the Subtitle Luminance setting was persistent, but it resets to default after every power off. (The UB9000 model has Subtitle Size, Synchronization and Character Code options that the UB420/UB820 doesn't.) It also supports 3D, and has a "Pop Out Level" adjustment (0 default, to 4 max). See below for other player video and audio option settings, including screenshots.

Scratched Discs:
My UB420 seems more sensitive to scratched discs than the Sony X800. (I've not tested again with new firmware 1.69, but doubt that matters.) My "Mummy Returns" 4K disc has major scratches, with 2 long scratches across almost the entire disc. (Many complaints on scratched discs from the 4K Mummy Trilogy's cardboard sleeve packaging.) It had more severe playback problems in the UB420 than in the Sony X800, although both players had freezing/skipping problems due to the disc's condition. (This is why I avoid cardboard sleeve packaging, especially with 4K discs.) That 4K scratched disc is (so far) the only one I've had a problem with in the UB420. (My previous Panasonic DMP-BDT500 was also very prone to problems with scratched discs.)

NTSC DVD (480i) Playback:
I use this player for 4K/UHD and Blu-Ray discs only, so the fact NTSC DVDs don't look as good (in my opinion) as my Sony's playing NTSC DVDs isn't an issue for me. (IMHO, Panasonic doesn't seem to de-interlace 480i DVDs as well as the Sony players.)

I only use it for Disc Playback:
My UB420 is used for disc playback only. I don't use streaming, apps or any file playback via USB. (Like all my disc players, I don't use any Network connections, Ethernet or WiFi.) I've seen users that care about streaming and/or file playback support say the Panasonic players are not a good choice, to put it mildly. (It can't even read my USB Flash drive's PNG files I use to test for OLED TV bad pixels and burn-in.)

Remote Control:
Many complain about the UB420/UB820 Remote Control, especially that the Netflix button is too close to the UP Arrow key. It's not backlit, but few OEM remotes are anymore. I like the dedicated HDR Settings button, but wish it had a Subtitles button. (The UB9000's remote has a Subtitle button, and is backlit. It's a popular replacement for UB820/420 owners.) The UB420/820 Remote has a "CC" (Closed Captions) button (just under Eject button) - I wish it had been a Subtitles button.

Also some simple functions require multiple button presses - for instance you have to press the Status button twice to see the movie's current chapter/time. (After a year of use, I've worn off the remote's label for the Status button.) Sony remotes show that info (and more) with 1 press of their Display button. I think Sony did a much better job with their compact remotes. (Sony's Subtitle button enables the first subtitle with 1 press; repeat presses cycle through all options including Off.)

UB420/820 Remote Control

I entered the code for LG TVs so that the UB420/820 remote's TV On/Input/Volume keys work on my 2015/2016 OLEDs. Despite its flaws, it's still better than the small LG 870/875 and 970 remotes (with a single AAA battery, weak IR) I had been using most often previously. (I'm in the minority that doesn't care for Harmony remotes. My favorite remote is the OPPO UDP-203 one. Great layout/key features and an automatic backlight when picked up, but can be disabled.)

Build Quality:
The UB420 doesn't have the solid build quality of the Sony X800 (or the UB820 model), but at $149.99 sale price, with features like the HDR Optimizer (useful for my OLED), and its reliability (so far) with BD100 UHD discs - I have no regrets (yet).

Drive Noise:
I've seen some comments from UB820/420 owners on drive noise, but on the 2 UB420 I've tested I only hear the drive during power-up seeks. (I've not put any unbalanced discs in it however. I replaced a 'Flight of the Phoenix' blu-ray that sounded like a buzz-saw in every player.) The UB420 I use currently is on top of my Sony BDP-CX960 (400 disc Blu-ray/DVD Changer) about 6ft from my seat, with a (very small/lightweight) Region B Sony S6700 on the top right side of it. (Completely open area against a wall, not placed in a rack.)

Internal Fan:
The UB420 (and 820/9000) has a small cooling fan, which I consider a plus. (I think heat can sometimes be a factor in UHD player problems.) I've never heard the fan during use personally, but I have seen a post from one owner that reported freezes and said the fan spun up to very high speeds. He returned/exchanged that player for another one that didn't have the problem. (Suspected the first player may have had a loose or incorrectly installed heat sink but didn't remove the top cover to check - just did a local store return/exchange.)

Using the remote control, go to Home -> Setup - > Player Settings.
(First are the Video settings; Audio settings follow below.)

HDMI Menu Settings for Player Output
In the HDMI main menu, with my 4K/UHD TV, I set output resolution at 4K, not Auto(4K),
to reduce HDMI handshakes seen with Auto setting. Below is a screen capture of my HDMI settings.
(I'm using a single HDMI cable (video+audio) to my Onkyo RZ830 receiver.)

(Above is from UB420. UB820 & 9000 have a Dolby Vision Setting)

4K60 Settings for 4K 60Hz Content
Here's Panasonic 4K60 player settings info you may find useful. I set 4K60P to "(4:4:4)" Chroma, but remember HDMI 2.0x does not support 4K60P 4:4:4 Chroma at more than 8-bit, due to bandwidth limits.

The player's settings info notes that when "4K60P(4:4:4)" is selected, it will output either 4K/60P 4:4:4 8 bit or 4K/60P 4:2:2 12 bit. I see the 4:2:2 12 bit with UHD/HDR 60Hz movie discs using my settings including Deep Color Output Priority set to 12 Bit. (The other 4K/60P option is 4:2:0, which will always be sent in 8bit per the player's settings info.)

The player will run a test to see if your hardware (player output cable to the TV, including any Receiver in the path) can run 4K/UHD at 60Hz. (If the 4K 60Hz test screen appears, it passed.)

For my 4K LG OLEDs (using Onkyo RZ830 receiver set to Enhanced 4K HDMI mode), I set the Panasonic player's HDMI->4K60p Output to "4K/60p(4:4:4)" and in HDMI Advanced Settings, set Color Mode to "YCbCr(Auto)", and Deep Color Output to "Auto(12bit Priority)". Some displays may have banding with 12 bit, or may prefer to do the Chroma upscaling in the TV instead of the player doing the 4:2:0 conversion. (All 4K/UHD & Blu-Ray movie discs are 4:2:0 Chroma.)

HDMI Menu Advanced Settings
The last item in the HDMI Menu is the Advanced Settings submenu.
Below are my notes on Deep Color Priority settings,
but first here's a screenshot of the player's HDMI settings I use:

The HDMI "Advanced Settings" page, showing settings I use

(The HDR/Color Gamut Output setting has an option for HDR to SDR(BT2020) mentioned in my Notes on UB420 use above, which also has details on features like Subtitle brightness adjustment, my experience with BD100 4K discs, the Remote Control, scratched discs and more.)

Choosing the HDR TV Type (in Advanced Settings)
(The 9000 model has more options than the 420/820 models, useful for some Projector owners.) Since my 2015/2016 OLED TVs are closer to 500 nits max than 1000 nits, I set the TV type to "Basic Luminance" (500 nits), not OLED (1000 nits). The optimizer does a better job at that setting for my older OLED TVs in my experience. And in some cases like "The Meg" 4K where the sky is blown out/clipped (on any TV), I adjust Optimizer settings to where the sky shows clouds, detail, etc. - a huge difference. You can adjust HDR brightness, dynamic range, black level, etc. (As an OLED owner, I wish there was a way to change the user interface's Yellow highlight color to either White or Gray.)

Deep Color Output Priority (10 Bit or 12 Bit)
Here's info on the Deep Color Output Priority (10 bit vs 12 bit) option when playing a 4K/UHD 60P disc:

4K60P Chroma Output with 10-Bit Priority
• 4:2:0 (10-bit)
  (All Disc content is 4:2:0)
  
  4K60P Chroma Output with 12-Bit Priority
• 4:2:2 (12-bit)

HDMI 2.0 Supported Modes

Audio Setup Menu Items
• Digital Audio Output - Bitstream (for Dolby & DTS)
• Digital Audio Output - BD-Video Secondary Audio OFF

In the main Audio setup menu I also set Dynamic Range Compression to Off.
(I do not want the player to compress or limit Audio Dynamic Range.)

About the 7.1ch Audio Reformatting Option
The "7.1ch Audio Reformatting" option is the last item in the HDMI Advanced Settings (above)
Here's what the Panasonic User Manual PDF (Page 30) says about that feature:

"7.1ch Audio Reformatting
Surround sound with 6.1ch or less is automatically expanded and played back at 7.1ch.
If "Off" is selected, sound is played over the original number of channels.
(Note that in the case of 6.1ch audio, playback will be at 5.1ch.)

Audio reformatting is enabled in the following cases:
- When you have selected "PCM" in "Digital Audio Output". (and)
- When the audio is Dolby Digital, Dolby Digital Plus, Dolby TrueHD or LPCM. (and)
- BD-Video playback."

I Turn Quick Start Off (in System Settings)
I also turn off "Quick Start" in System Settings. (I do this for all my players and TVs. I never liked any sort of "Quick Start" feature. I've also seen cases where Quick Start enabled on TVs sometimes caused odd issues, or where turning off "Quick Start" solved a problem.)

When playing a disc in my UB420, pressing STOP quits to an "Ultra HD™" logo screen, not the main player home screen.
(A second press of Stop is required to fully quit to the main player home screen.)
Here's the procedure I used to play some Region B locked blu-rays:

1. Insert Region B locked Blu-Ray.
2. Player attempts to load it...
3. You see the incorrect Region warning. **
4. Press STOP on remote, then press TOP MENU button.
5. If you then see a warning (top right of screen) "This operation not available".
6. Press TOP MENU Again.
7. Disc then loaded the Movie's main menu.

** Unlike the above routine, Second Sight's Region B "Drive" blu-ray didn't show a region warning/error,
it just displayed the UB420's "Ultra HD™ Blu-ray" Logo screen. Then pressing Top Menu loads the disc's Main Menu.
(Attempting to play that disc in my Region A Sony X800 also didn't display a region error, it just refused to load.)

Once you get to the disc's movie menu, it functions as normal.
This trick won't work on some Region B locked discs, like those that ignore any button presses after the incorrect region message. (Again, examples of Region B locked discs I tried that didn't work are Terminator 2 3D, and Ratatouille 3D. I'm sure there's others.)

Although this tip for Panasonic players has worked with some discs for years, a firmware update could break it. And again, it doesn't work on all discs - some discs block all input after a region error. (That's why I have a Region B Sony S6700, that also plays Region 2 DVDs.)

• Playability of Blu-ray Disc™

The unzipped firmware file is dated 8/20/2021. Finally a US update after over 2 years (v1.60 was July 2019).
(FYI: If you have an all-region modified player, a standard (OEM) firmware update can disable that feature.
Before updating, ask the vendor that modified your player if it's safe to update via the internet or USB download.
(Some vendors may have updated versions of their modified all-region firmware for previous customers to apply.)
Other than Oppo hardware mods, I've seen some claimed "Hardware region-free" players that had the feature
disabled after an OEM USB firmware update. The buttons to switch regions on the Remote no longer worked.)

Initial reports on 1.69 firmware say it fixes the previous problems with some Dolby Vision discs.
The 1.69 firmware didn't break the region bypass trick that works for some region locked discs.
I updated my UB420 first to v1.69 (no player LCD display, so see notes below), and later a UB820.

Updating my DP-UB420 Model (without built in display)
I had previously updated my USA DP-UB420 with firmware 1.66 (CN firmware from info below here), and updated to firmware v1.69 using the UB420 Firmware update how-to below, as the UB420 has no built in display for status messages like the higher end models do. After more than 5 minutes (LED flashing), it finally finished and all seems OK. It did not change any of the player settings I had previously, and player system info showed firmware 1.69 installed. I was hoping they'd make the Subtitle Luminance setting persistent, but it still isn't with 1.69 on my UB420.

I unzip the firmware download self-expanding .exe file and copy it to the root of a FAT formatted USB flash drive. After powering on the UB420, connecting the USB flash drive results in a reboot and rapidly flashing red LED during the update process, which takes several minutes - be patient. (The 1.69 update took over 5 minutes.)

The UB420 firmware update is finished when the red LED repeats a series of 3 flashes, pause, 3 flashes. Then Power OFF and remove the USB Flash drive before powering ON again. (You can check the firmware version in the Player's Setup -> Player Settings -> System -> System Information -> Firmware Version Information screen.)

BTW: Even with firmware 1.69 in my UB420, when playing 4K/UHD Discs, my Onkyo RZ830 still doesn't show "Premium Content" during 4K UHD/HDR Disc playback. (My Sony X800 and LG UP970 players do, as I mentioned earlier.) I've tried everything including a player reset, tested with HDR optimizer Off and On, etc. Again the UB420 is sending UHD/HDR content, and the TV's HDR flag shows every time, but the RZ830 doesn't display the "Premium Content" in Video info like it does with my other 4K/UHD players.

Update on v1.69 Firmware & Dolby Vision Discs:
Although users reported firmware 1.69 fixed the Dolby Vision problems with discs noted above, I've seen 2 UB820 owner reports that there were still some intermittent flashes (or sudden brightness changes) with Dolby Vision enabled on the 2021 released 4K/UHD discs of Halloween (esp. 3 & 4), and Star Trek I-IV using Dolby Vision. (Not as bad as the Dolby Vision flashing with some discs before 1.69 firmware, but still seen at times during playback in Dolby Vision mode.) If this is an issue for you, try disabling Dolby Vision in the player's settings. (2 Panasonic owners later replied they didn't have any issues with the new 4K Halloween discs, so this may be related to the TV model(s) used.)

Update on Donnie Darko (TC) UHD Disc:
The link I had posted to Arrow's Donnie Darko UHD (Theatrical Cut) Replacement Program page is no longer online as of Nov. 2021. Some reports in spring 2022 I saw said even the later repackaged sets they bought had the problem disc, not the "V2" corrected disc. (A blu-ray.com forum user post in late June 2022 said he was unable to get a his problem disc replaced despite repeated attempts.)
(Earlier comments follow, posted before firmware v1.69, but no reports it helped.)
The "Donnie Darko" Theatrical Cut UHD disc from Arrow is reported to have severe stutters throughout with UB420, UB820, and UB9000 (problems in HDR10 and Dolby Vision modes). Also problem reports from some Sony X800M2 owners (one owner noted no problems), and several Sony X800 owners said it played OK. (The original Sony X800 player has a different SOC than the X800M2, which has Dolby Vision support.) Also saw problems reported from Xbox One S, Xbox Series X (stuttering) and PS5 (1 noted stuttering, 1 said the Theatrical Cut UHD disc wouldn't even load on his PS5). I wish those posting reports included the player's firmware version, but none did. (NOTE: Those reports were from before Sony 4K/UHD players firmware updates in late Aug. 2021 & late May 2022. Most recent firmware linked at our TVs/AVRs/Players Firmware Updates Listing.)

Tip for "A Quiet Place" 4K Disc Freezes (2 samples from Best Buy Steelbook)
(TLDR - if your "A Quiet Place" 4K Disc freezes or locks up, try cleaning it with isopropyl alcohol.)
After seeing hard freezes with the "A Quiet Place" 4K UHD disc from 2 samples (both from Best Buy's 4K "claw marks" design Steelbook), I wanted to post a tip that helped. (Cleaning the 4K disc with isopropyl alcohol.) In May 2021, while in a Best Buy store I saw one red "A Quiet Place" 4K steelbook and bought it. (A restock with a minor dent that I flatted out with a spoon from the inside surface. When first released, I bought the standard 4K package instead.) After a friend said he finally opened his 4K Quiet Place Best Buy steelbook (bought years ago) and the (spotless he said) 4K disc froze around the 4 minute mark, I had to try the 4K disc from my steelbook. (Normally these problems are not typical, and I had played my standard package 4K disc OK.)

I used my Sony X800 with firmware M36.R.0338 (before the August 2021 firmware updates for Sony 4K Players), which had played my previous 4K Quiet Place disc OK (from the standard package back when it was first released). However the 4K disc from the Quiet Place Best Buy steelbook locked up the Sony X800 after about a minute into the movie. (Froze at the point where you're seeing the outside of the store at the start of the movie.) I had to pull the Sony X800's power cord, as it wasn't responding to the remote or the player buttons. Although the disc appeared pristine (no visible dust, smudges or scratches), I cleaned the disc's playing surface with household 70% rubbing alcohol (isopropyl). Wiped it off with a new micro-fiber cloth. (A used cloth sometimes retains debris that can scratch a disc.) I powered the Sony X800 up, cleared the flash storage (to ensure it wasn't corrupted from the freeze/power disconnect) and the disc played perfectly.

Oily Residue in 4K/UHD Disc Cases
After having such good luck with 4K discs in the UB420, I'd gotten out of the habit of cleaning 4K discs lately. (In the past I've used Dawn liquid soap, this time I used isopropyl alcohol.) Some 4K discs seem to have some sort of (invisible) film, either from the original disc mfr, or transferred from the oily residue inside the plastic disc cases. I think this residue is a case manufacturing mold release agent or lubricant (see why below), although some think the plastic is outgassing. (I commented on that topic many years ago, regarding oily HD DVD cases and cleaning 'cloudy' HD DVD discs. Some HD DVD cases were a different type of plastic (inside surface was matte, not glossy) that were always dry inside. The disc cases with matte plastic inside never had any oily film inside like the glossy cases often had.)

Why I think the Oily Film in New Disc Cases isn't from Outgassing
The insides of new 4K UHD disc cases often have a LOT of an oily film, which I think is the manufacturer's release coating for the injection mold or lubricant from the machines that process the cases. Inside some cases you can see the round suction cup spots, which shows this oily film was already present when the case was manufactured, and not something that outgassed over time. Several times I have had to use isopropyl alcohol to remove it from 4K/UHD discs (that appeared pristine) to fix playback issues, after repeated cleaning with soap and hot water didn't solve playback problems. (The most recent example was I Know What You Did Last Summer UHD disc.)

• Create a directory named sub (lower case) on your USB drive (FAT format).
• Rename the subtitle file as sub.srt (all lower case)
• Copy the sub.srt file to the sub directory
• Connect the USB drive to the player (of course)
• Play the disc, press Option button on remote control
• From the top left "Operation Menu", select Subtitle Settings
• A new "External Subtitle" option, under the standard "Subtitles" option.

FYI: I tried making a test sub.srt file (text editor) but didn't see any external subtitle option with my UB420 updated to firmware 1.66 (from below FW source). This may be another feature that's not supported with the low end UB420 model, or the posted firmware simply doesn't have that feature. (I was later told external subtitles only worked with modified firmware.)

(China) Panasonic DP-UB420/UB820/UB9000 Firmware Update 1.66 (now v1.69) (NOT the USA page)
(I had flashed my USA UB420 with this firmware OK, but you assume all risk of updating yours.
As mentioned earlier, I use UB420 for Disc playback only, not Network/USB files, or streaming.)

Some Panasonic players shipped with firmware 1.64 or 1.66, but the USA firmware page still had 1.60 from July 2019 when this was written. (See above for new 1.69 Firmware posted 9/29/2021.) CN Firmware version 1.66 listed the usual (improved) "Playability of Blu-ray Disc™", but didn't fix problems with some Dolby Vision discs.) Although rumored to add support for external subtitles, it didn't.

The Panasonic (China) FW Download page had firmware 1.66 - but now updated to v1.69, like the US page.
v1.66 source was https://fdl.jpn.support.panasonic.com/pc/en/bd/ub420/UPDATE_UB9000GK_V166.exe.
(The page heading says "DP-UB9000 Firmware Download (China)", but URL has ub420 in the path.
And as noted earlier, the same firmware file is used for the UB420, UB820 and UB9000.)
Linked download page has info on installing via USB flash drive (FAT format, not NTFS or exFAT).
(For updating the UB420 model, see my update tips as that model has no display for status messages.)

Although that page has a note in Green text that says "You will not be able to install firmware designated for a region that is different to the region in which you purchased your Panasonic Blu-ray Disc™ Player", I'd seen 2 users that installed it OK on (AU) Panasonic UB9000, and (US) UB820 players. As noted in the USA firmware notes here, the UB420, UB820 and UB9000 use the same firmware, although some features (like Dolby Vision) are disabled in UB420 model.

(CN) Firmware 1.66 Update did not change my USA Player's Region
After the 1.66 update was installed, I wanted to verify it had not changed my player's region (USA is region A). I tested a Region A locked Blu-Ray ("Gone in 60 Seconds") and it played fine. (4k/UHD Discs are typically region-free, with some rare exceptions.)

= Other Site Topic Areas =
Recent Updates | Mac Mods/Upgrades | Storage | Video & Displays | Audio & Home Theater | Apple Updates & Tips