It is currently 28 Mar 2024, 15:03

All times are UTC [ DST ]


Search found 7 matches

Author Message

 Jump to forum   Jump to topic

Posted: 20 Dec 2020, 03:40 

S-Video was a solution for a broken system the US established. My honest belief is that as Japan was trying to phase out NTSC and move to MUSE HD broadcasting, they were pushing hard for the eventual obsolescence of composite video connections (which had only moderate acceptance by the time MUSE broadcasts started in 1989) due to the inherent phase issues from the color subcarrier.

S-Video connections transmit luma (brightness/B&W) & chroma (color) separately to the destination, and would allow easy transmission of "old" 59.94Hz NTSC and 60Hz MUSE->NTSC reducing complexity of MUSE->NTSC downconverters and TVs. Composite, on the other hand, will artifact with 60Hz signals (besides the visual issues which are inherent to composite NTSC video itself).

LD is established to be a composite format but in an alternate dimension where analog MUSE became an accepted HD standard, there may have been small/standard definition TVs with no composite video inputs. To install an S-Video output in an LD player would have nicely "future-proofed" it and encouraged S-Video adoption.

To break a composite video signal out into the RGB components requires many precise filters and, if not calibrated correctly, will give you varying colors between each of your sources. It's much smarter to do it at the destination (i.e. TV) for consistency. In the analog domain, this also meant a lot of components. If you find old broadcast-grade composite to RGB/component transcoders, they're whole 1U rack-sized units with required calibration for each color channel! Not something you want to put into a tiny, affordably-priced LaserDisc player. Separating the NTSC luma from the chroma is much easier & cheaper since the colors should be guaranteed to remain at their relative voltages and have correct timing via one simple cable. You can see in the service manuals for LD players with S-Video that the signal paths break the video into luma & chroma with no RGB separation. OSDs were easy to implement too just by modifying the luma channel and passing through chroma unmodified. S-Video was the easiest and cleanest solution for all analog standard-definition video transmissions going forward.

Besides MUSE (which, while component video, remained too expensive and niche for most Japanese after the economic bubble burst in the early 1990's), it wasn't until 1996 when DVD, with native component digital video, became available to the market. Terrestrial ATSC digital HD came to the US also in 1996 in digital component which caused some manufacturers to start adding component inputs to all TVs...but all remaining LD player manufacturers were Japanese. The more-widely-accepted Japanese ISDB digital HD didn't come to Japan until 2004, long after LD was, for all intents and purposes, dead. The writing was on the wall by the mid-90's that analog was dying. "Long live the native component digital formats!," they cheered. No more effort was placed into improving analog video or adapting it to an RGB/component world.

tl;dr: RGB/component is a pain to extract from composite. S-Video was to be the new (Japanese) standard until digital happened and killed all hope for a better analog future faster than Speedy Gonzales on a bullet-train.

 Jump to forum   Jump to topic

Posted: 21 Apr 2021, 01:41 

A few years ago, I was casually strolling down my local flea market when I found a very unusual, very beat-up Imation LaserDisc...
img137 (Medium).jpg

Besides the fact that it was for Best Buy, the late manufacturing date and the implication it was a back-up for an HD master piqued my interest!

I just recently captured it and put an edited version up on YouTube:
https://www.youtube.com/watch?v=z5qadXgWjrI

It's a very, very high-quality 4:3 crop of an obvious 16:9 source. With the loss of picture, I'm not sure I understand what the purpose of a back-up like this is. Was it not a back-up and instead a distribution given to stores that didn't yet have a HD infrastructure?

Does anyone have any information on this disc, have information on the purpose of such a disc, or have similar, pressed HD-mastered "back-ups" on LD from the turn of the millennium?

 Jump to forum   Jump to topic

Posted: 13 Jul 2021, 06:55 

adhdvs wrote:
I wonder if this upload was sourced from a TV broadcast.


The source of that video, based on the watermark, was ep, a VoD-like satellite service that broadcasted between 2004 & 2007 in Japan.

 Jump to forum   Jump to topic

Posted: 18 Sep 2021, 23:16 

Update time!

I was able to get TEST mode going (Thanks C++...Fun fact: TEST is the same button as DISPLAY! ESC is the odd one) but...
First, the test mode that the remote pulls up is COMPLETELY different from what the service manual showed. It's a very simple, cryptic interface that seems to show main microprocessor information like playback status, activity, etc. Functionality of the unit is not changed. Please see "ManualTest.jpg" to see what this screen looks like.
Then, after poking around, I discovered that to get into the ACTUAL test menu as shown in the manual, both pins on CN714 on the CONT board need to be shorted for a couple seconds and then released. The player then reboots into the real test mode.

The great news about test mode is that I can turn the laser on indefinitely by hitting the play button on the remote.
The bad news about test mode is that I can't get the spindle motor to turn on. I tried poking all the buttons on the remote and I could do pretty much everything the S/M says, including switching between the three spindle "loops" (HD, FP, and FG), but I couldn't do anything to get the last digit to switch to anything but "1" (Brake). C++, is there a command combo or something I'm missing? I'm guessing that since it still doesn't recognize a disc it won't let me control the motor. Please see "PCBTest.jpg" to see what the test screen shows if I turn the unit on in test mode and press play on the remote.

I then moved on to taking a look at the circuitry around Q122. We might be onto something... According to the schematic, this circuit should be supplying -8V? It looks like I'm only getting -3.7V out of it! I wrote down most of the voltages in this circuit on the schematic (when the laser is on) and attached it as "LaserPowerVolt.jpg." Q124 and Q123 are hard to get to safely so I didn't document those voltages. I also noticed that Q125 gets hot very quickly (C200 seemed to get hot too after an extended period but I wonder if that's from proximity). It looks like this circuit works as a simple voltage regulator; the HZS9.1NB2 Zener (D110) has a breakdown voltage of 8.61V to 8.99V according to the data sheet. At this point, I'm wondering if Q125, HZS9.1NB2, or Q121 might be bad. The problem is that the Zener and the 2SA933 (Q125) are discontinued and no longer available...so I'll need to find a substitution! I also measured across the Zener and the 2SA933 in-circuit with my DMM's diode tester. The diode still tested like a diode (read about .7V in one direction...). The 2SA933, however, tested like a diode across all pins...??? The base and collector read 1.2V in one direction and .6V in the other.
I also found that there there is an undocumented extension to the circuit off of Q121. It appears to pull up the base to V+5S with like 56k of resistance? Without taking the board off, I can't really tell what's going on there. It just pulls the base of Q121 up to +5V when the laser is off.

Thanks to everyone for your help! I'm really starting to think that this might not be the laser after all! (+5 points to my intuition! :) )

 Jump to forum   Jump to topic

Posted: 19 Sep 2021, 02:19 

Interesting- I did not know that.
Both are device 168, function 67! ESC is function 95. I have an IR device uploaded to hifi-remotes.com for the X0 that I'll be updating with the ESC code shortly...

I've always just pressed play on front of player (twice).
Just tried it and it made no difference. :( Just keeps hunting for focus.

It is common for a lot of these active components to be NLA, so I have had to either find surplus stock or match the datasheet as close as possible. eBay has 2SA933. I'd order replacements for those three components (at least two of each).
Will do! What's your opinion of the 1N4695 as a substitute for the HZS9.1NB2 ? It looks like the leads are a little wider in diameter but I'm not sure I have a choice here.

It is a Pioneer, not a Sony!
lmao Ain't that the truth!

 Jump to forum   Jump to topic

 Post subject: Re: SONY HDL-2000
Posted: 18 Nov 2021, 06:53 

Sold as junk, but here's one for sale right now in case someone wants to burn some money :)

JPY 85,000 for a junk/tray does not open and no disc coming along...

I think the previous one sold for a few JPY 1,000's but if you don't have the discs, it's a very expensive brick!

Julien

I own two & posted the video above. It's easy to fix the tray issue; the loading belt on these units are all stretched out and it may have aged lubricant. Re-lube the tray and pop on a new belt and you're good to go.

Also, unlike what the seller seems to imply, these are not backwards compatible with standard LDs.

Compatible HDVS discs are hard enough to get, but the real problem, like all Sony LaserDisc equipment, is reliability. Many of these have many, many hours from being run in continuous loops for shows, presentations, and R&D. Both of mine had problems. One has a burnt out laser and the other has a bad board. Service manuals are discontinued/unavailable from Sony. I was able to get one of mine working by mixing & matching parts.

HDVS is an investment.

Added here for the specs (and pics to follow)

Sony HDL-2000

Julien

I added additional information.

Let me know if there is anything else you could use.

 Jump to forum   Jump to topic

 Post subject: Re: AHD
Posted: 29 Jan 2022, 04:40 

There is an AHD decoder available on Yahoo Auctions with a starting bid at ¥30,000... I will not link to it, but I'm mentioning this since the seller is a notorious flipper (jun6462000) who purchased this from the original owner on Mercari less than a month ago. Included disc and decoder S/N matches up. He negotiated with the seller from something like ¥7,000 down to ¥4,800 ( https://jp.mercari.com/item/m48692374583 ). In the Mercari comment communication, he claims that he has a VHD player. He is now trying to pull a high profit on YA! claiming that he doesn't have a VHD deck and that it is sold as-is. There is a high probability that he either lied to get a deal or found it is defective in testing. Buyer beware.

And now I keep finding more Japanese devices with this "RGB21" or "RGB Multi":

RGB-21 was used mostly on PCs and devices that produced RGB graphics (such as the Super Cassette Vision, Sega Genesis, and Sega Saturn). As others said, it's almost pin identical to SCART with only a couple pins changed.

You can find this connector on many CRT monitors and was the precursor to the VGA connector. Many computers like MSX PCs used it which is why it is found on the AD-7000, for imposing digital images for MSX RGB computer graphics produced using the MSX interface which could be daisy chained through the AHD decoder. One of the available four data channels on the AHD disc could be used as a program datastream to the PC per white paper specifications. I am not sure if that was used in application, but the RGB-21 would at least allow for high quality text and interactive program overlays.

To my knowledge, no MSX AHD discs were ever offered or produced.
Page 1 of 1 [ Search found 7 matches ]


All times are UTC [ DST ]


Jump to: