Questions that do not deserve a thread

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SavagePencil
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Re: Questions that do not deserve a thread

Post by SavagePencil »

Dochartaigh wrote: I don't think I've ever had one plug into ethernet first and let me do anything with it - I always had to use a USB to Serial cable the first time + their windows software to turn on DCHP as outlined below, then you can use ethernet regularly afterwards:

viewtopic.php?f=6&t=63212


Yours might be different since it's an Extron DXP (assuming HDMI version), but I think those first steps are the same at least. By the way, what are you using this for? I was never able to get similar Extron HDMI switchers to work - they only (for the majority) like standard-type signals and would give me black screen dropouts (if they would display at all) with a ton of the OSSC signals for instance (if my memory serves I was getting some dropouts on original Xbox 480p too when ran with an Extron DSC 301) – no matter what settings like EDID I changed (and I changed literally every single settings for probably 10+ hours to try to get it to work).
I had an AV friend get me the Matrix Switcher program, and I was able to get into it via USB -> Serial port (for some reason it liked being COM3, while it's COM1 for my Corio downscaler). The switch was in Executive mode. I probably should have done a factory reset when I received it.

Adjusting all of my EDIDs to 1080p/60hz/stereo has made it much more reliable. I have a 360, a Switch, a MiSTer, a laptop, and an OSSC routed to it. The reason I started doing this in the first place was the fact that my OSSC was not displaying the gray bar, but would work with 720p signals. The device required multiple attempts to get it to switch properly because a lot of hardware wanted to send a 1080p signal, but the default EDIDs were all 720p. I will update if I am getting drops, but so far it's been fine.
Dochartaigh
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Re: Questions that do not deserve a thread

Post by Dochartaigh »

SavagePencil wrote: I had an AV friend get me the Matrix Switcher program, and I was able to get into it via USB -> Serial port (for some reason it liked being COM3, while it's COM1 for my Corio downscaler). The switch was in Executive mode. I probably should have done a factory reset when I received it.

Adjusting all of my EDIDs to 1080p/60hz/stereo has made it much more reliable. I have a 360, a Switch, a MiSTer, a laptop, and an OSSC routed to it. The reason I started doing this in the first place was the fact that my OSSC was not displaying the gray bar, but would work with 720p signals. The device required multiple attempts to get it to switch properly because a lot of hardware wanted to send a 1080p signal, but the default EDIDs were all 720p. I will update if I am getting drops, but so far it's been fine.
Mine likes COM4 - seems to be random based on the computer but glad you got in!

Would you mind sharing exactly what setting(s) (like on what tab(s) and options to choose) you used to fix your issues? Might help me or others with these Extron HDMI matrix switches.

I don't have the DXP but the multiplane SMX switcher with HDMI cards from the same Extron line-up/era as the DXP. Could very well explain why yours is working and my two don't like the OSSC (I tried like ~14x consoles on the OSSC, with 2x to 5x - I wish my memory was better or that I took notes but just know some worked but many had dropouts so I stopped using the SMX).
SavagePencil
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Re: Questions that do not deserve a thread

Post by SavagePencil »

EDIT: It's really quite simple to update the EDID.

1. From the Matrix Switchers program, go to Tools -> EDID Settings
2. For each input, select the resolution you are anticipating. For mine, I'm setting 1080p @60hz stereo.
3. The "Advanced Info" button on this dialog can also show you which resolutions have passed through it, which can be very useful!
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NewSchoolBoxer
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Re: Questions that do not deserve a thread

Post by NewSchoolBoxer »

I have the Datapath E1S and sound card for pixel-perfect-ish RGB + Component video but I want to go down the fruit loop to S-Video and Composite pixel-perfect-ish recording as well. Set on Nintendo and Sony 240p/480i. No need to stream.

Is there a device under $150 that is accurate, video quality flaws and all?

My current plan is to buy a VHS+DVD recorder that accepts S-Video and Composite (and RF to boot) and burn to DVD but then I don't know how accurate one make/model is to another.
Issac Zachary
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Re: Questions that do not deserve a thread

Post by Issac Zachary »

NewSchoolBoxer wrote:I have the Datapath E1S and sound card for pixel-perfect-ish RGB + Component video but I want to go down the fruit loop to S-Video and Composite pixel-perfect-ish recording as well. Set on Nintendo and Sony 240p/480i. No need to stream.

Is there a device under $150 that is accurate, video quality flaws and all?

My current plan is to buy a VHS+DVD recorder that accepts S-Video and Composite (and RF to boot) and burn to DVD but then I don't know how accurate one make/model is to another.
Very interesting! May I ask more details? Do you want a digital signal that is exactly the same as the analog signal (i.e. interlaced, etc.)? What are you wanting to do with that? Compare signals digitally?

I think there can be a big difference between devices, though I'm no expert. One thing that pops into mind is the term "comb filtering". Sounds like you're the first person to want to try this. Let us know what you find out!
Dochartaigh
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Re: Questions that do not deserve a thread

Post by Dochartaigh »

SavagePencil wrote:EDIT: It's really quite simple to update the EDID.

1. From the Matrix Switchers program, go to Tools -> EDID Settings
2. For each input, select the resolution you are anticipating. For mine, I'm setting 1080p @60hz stereo.
3. The "Advanced Info" button on this dialog can also show you which resolutions have passed through it, which can be very useful!
Thanks, and same thing I tried on my Extron SMX but unfortunately I still had drop-outs. Oh well, my 2x HDMI splitters and 4x HDMI switcher are working great and have taken the place of my SMX so at least my setup isn't suffering from the incompatability. Glad your DXP is working well!
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NewSchoolBoxer
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Re: Questions that do not deserve a thread

Post by NewSchoolBoxer »

@vol.2
I bought a cheap LCR-T4 + 9V battery and co-opted my multimeter's leads to measure JP21 pin 19 (Green) to Multiout pin 12 (Green / Y) and got ~220 μF as expected. No need to open the cable now but cost me $15.
https://imgur.com/dLCPPuA
People say the ESR and Vloss on those kits are inaccurate so I haven't set a baseline to make a better cable.

@Issac Zachary
Thank you! The forum where I learned that only L5 PVMs can display 480p is probably not the best place to ask about recording S-Video. :? Yes, I want exact digital recordings of every cable type. I feel I can trust the ADC on a VHS/DVD Recorder. Not going to treat 240p as 480i. I see recommendations for I-o DATA USB that takes S-Video and Composite. Accepts 240p but I don't know how it's processed. DVD should sample at 44.1 kHz for 29.97 fps recording. I assume it will dodge flickering from 60.0988 fps SNES and 61.1679 Super Game Boy.

If that's Phase 1, Phase 2 is electrically measuring cable quality. We're stuck with "the quality looks better in person" because video is compressed into 4:2:0 on YouTube. I want to prove how good each cable on the market is and promote which are best value for the money. I have a "Proof of Cable Quality" post that elaborates. Phase 3 is profit.
Issac Zachary
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Re: Questions that do not deserve a thread

Post by Issac Zachary »

NewSchoolBoxer wrote:@vol.2
I bought a cheap LCR-T4 + 9V battery and co-opted my multimeter's leads to measure JP21 pin 19 (Green) to Multiout pin 12 (Green / Y) and got ~220 μF as expected. No need to open the cable now but cost me $15.
https://imgur.com/dLCPPuA
People say the ESR and Vloss on those kits are inaccurate so I haven't set a baseline to make a better cable.

@Issac Zachary
Thank you! The forum where I learned that only L5 PVMs can display 480p is probably not the best place to ask about recording S-Video. :? Yes, I want exact digital recordings of every cable type. I feel I can trust the ADC on a VHS/DVD Recorder. Not going to treat 240p as 480i. I see recommendations for I-o DATA USB that takes S-Video and Composite. Accepts 240p but I don't know how it's processed. DVD should sample at 44.1 kHz for 29.97 fps recording. I assume it will dodge flickering from 60.0988 fps SNES and 61.1679 Super Game Boy.

If that's Phase 1, Phase 2 is electrically measuring cable quality. We're stuck with "the quality looks better in person" because video is compressed into 4:2:0 on YouTube. I want to prove how good each cable on the market is and promote which are best value for the money. I have a "Proof of Cable Quality" post that elaborates. Phase 3 is profit.
Awesome! That would be awesome! Right now I'm using only S-Video on all my consoles (Snes, Wii, PS2). And may stick with S-Video even when I get other consoles I'm interested in just because it looks so good and I haven't had time to attempt to mod my TV to accept RGB nor does it have a component input. By profit do you mean you intend on selling the best cables out there?
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vol.2
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Re: Questions that do not deserve a thread

Post by vol.2 »

NewSchoolBoxer wrote:@vol.2
I bought a cheap LCR-T4 + 9V battery and co-opted my multimeter's leads to measure JP21 pin 19 (Green) to Multiout pin 12 (Green / Y) and got ~220 μF as expected. No need to open the cable now but cost me $15.
https://imgur.com/dLCPPuA
People say the ESR and Vloss on those kits are inaccurate so I haven't set a baseline to make a better cable.
Glad you have your answer. I have one of those things, and it's good for quickly checking things. Don't worry about the esr as that is fine for and electrolytic. It's probably small surface mounts inside the cable. Unfortunately, surface mounts from that time period (mid 90's) are notoriously bad and they tend to leak when they see a lot of use. I've found this to be especially true of Sony devices from that time period. (I've recapped many small devices from around then). Then again, it's not a high power spot, so it might be fine. You might want to check it again after 6 mo or a year and see if it changes any.
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kitty666cats
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Re: Questions that do not deserve a thread

Post by kitty666cats »

Anyone own any of those inline TTL -> 75ohm attenuating mini-cables that Retro Access used to make? I was wondering if they are intended to have the male end (1 end is male, 1 is female) connected to the source (like an Extron Crosspoint, etc), or if the male end is intended to be connected to your display...
nmalinoski
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Re: Questions that do not deserve a thread

Post by nmalinoski »

kitty666cats wrote:Anyone own any of those inline TTL -> 75ohm attenuating mini-cables that Retro Access used to make? I was wondering if they are intended to have the male end (1 end is male, 1 is female) connected to the source (like an Extron Crosspoint, etc), or if the male end is intended to be connected to your display...
I don't think which end you connect it to makes a difference; it's not directional.
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kitty666cats
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Re: Questions that do not deserve a thread

Post by kitty666cats »

nmalinoski wrote:
kitty666cats wrote:Anyone own any of those inline TTL -> 75ohm attenuating mini-cables that Retro Access used to make? I was wondering if they are intended to have the male end (1 end is male, 1 is female) connected to the source (like an Extron Crosspoint, etc), or if the male end is intended to be connected to your display...
I don't think which end you connect it to makes a difference; it's not directional.
Cool, thanks for the peace of mind - I definitely didn’t see a discernible difference one way or the other!
RocketBelt
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Re: Questions that do not deserve a thread

Post by RocketBelt »

Is a Lumagen Radiance any good for deinterlacing with PS2? Are the various radiance models all the same with regards to deinterlacing?
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Fudoh
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Re: Questions that do not deserve a thread

Post by Fudoh »

The deinterlacing is good, but the unfortunately the whole processing chain on the Radiance is 4:2:2 only, so you get chroma upsampling and the Lumagens have always been messy at that. If you don't have the comparison to a pure 4:4:4 processor, it's not that bad, but it can be annoying, since it's otherwise a great machine.
RocketBelt
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Re: Questions that do not deserve a thread

Post by RocketBelt »

Thanks for the response, I currently have a VP50 for PS2 deinterlacing duties so am already in the 4:2:2 space I beleive. So I don't have a comparison to a 4:4:4 machine. I'm looking at a Radience as a backup device for PS2 deinterlacing in case the VP50 ever fails. Mainly because the prices for some Radience models are less than VP50 prices.
I tried one of the earlier Lumagens with the SIL504 and had no problem with input lag, but it combs a bit too much in comparison with the VP50. Is the Radience deinterlacing more comparable to the VP50 with regards to combing and input lag?
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Fudoh
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Re: Questions that do not deserve a thread

Post by Fudoh »

huh, it's been a long time since I compared these two. I think the DVDO is better in terms of video deinterlacing. The Radiance (you're probably looking at something like the XS, XD or XE) is considerably better in scaling though. For deinterlacing the Radiance uses the Gennum VXP (same chip as the Crystalio II), which makes it even weirder, since the Gennum in the CII and in the Optoma retain full 4:4:4 all the time.

If you want a visible upgrade from a VP50 you need a Framemeister. Or you wait how the OSSC Pro's deinterlacing turns out. On the later one chances are that deinterlacing will evolve over time.
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NewSchoolBoxer
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Re: Questions that do not deserve a thread

Post by NewSchoolBoxer »

Thanks vol.2! I never thought about surface mounts going bad. I need to test all cables I buy going forward.

To All: Do you see advice floated around that isn't proven? Anything you wanted tested?

[*] I used to be on "keep cables short" train, until I thought about it. Here is a nice Extron chart showing specs of two 75 ohm cables: https://media.extron.com/public/downloa ... 062409.pdf
Notice the resistance of the cable is rated by the frequency of the signal and the length in db loss / 100 feet. In analog television non-sync lines you're looking at ~6 MHz so 0.7 db loss at 100 feet. This is linear so 0.07 dB loss at 10 feet of cable. To give meaning, I found a chart using video game cables that gave 25.9 dB for Composite, 27.2 dB for S-Video and 30.4 dB for Component. So you need 185 feet of cable to degrade S-Video into Composite? Like I'm sure there is more noise at longer cable length but how about we actually test what cable limits are? Would be a shame if someone bought a 1 foot cable when they had a 6 foot one.

[*] The loss no one talks about is connecting components together - the interconnections such as SNES to SNES Multiout to Switcher input to output to TV for 4 connections. Not much online about it. One source uses 0.6 * sqrt(frequency in GHz) so 6 MHz is 0.6 * sqrt(0.006 GHz) = 0.05 dB loss per BNC connector: https://www.amphenolrf.com/faq/technica ... specified/

Seems easy enough to chain BNC or RCA connectors together and measure loss at NTSC and PAL frequencies.

[*] I get that "lag free" is a marketing gimmick and in the fine print it states lag is in the nanosecond range. To give, perspective, 1 million nanoseconds is 1 millisecond and one NTSC frame is 16.7 ms. Is okay then. We use CRTs or buy expensive scalers in part to prevent the 1 frame or so of lag from LCD analog to digital conversion. So what about the delay in the cable length, the propagation delay in transistors, rise and fall time in a square wave, capacitance lagging voltage and the 200 MHz clock speed in a typical FPGA? You chain enough ns delays together, when do you mismatch the sync and video signals?

Also, CRTs have lag. Here is a video showing that: https://www.youtube.com/watch?v=tDLQrGKEnVI
Basically, the 60 Hz rate means the top line is colored instantly, middle line at 1/2 frame of lag and bottom at 1 frame.

[*] TTL sync (4-5 Vpp) vs 75 ohm sync (0.3 Vpp) could damage your SCART equipment and television! Could it? Do we actually have capacitors that fry and transistors that get saturated at 5V in television circuits? I'm not saying people should test this on SCART televisions but I did read a thread here stating that, even on the same television, TTL may work or it may mess the colors up. No one mentioned permanent damage but SCART switchers is a different matter and gscartsw isn't covered under warranty when used with superguns. What are our voltage and current limits? viewtopic.php?f=6&t=66639
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vol.2
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Re: Questions that do not deserve a thread

Post by vol.2 »

NewSchoolBoxer wrote: [*] TTL sync (4-5 Vpp) vs 75 ohm sync (0.3 Vpp) could damage your SCART equipment and television! Could it?
Impractical to test because it would depend on the individual monitor or TV. You would have to look at the schematic and evaluate the circuit and anything upstream from the input to determine the effect of 5V. That would mean pulling datasheets to look at absolute maximum ratings in addition to a holistic evaluation of the sync input in the system.
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Kez
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Re: Questions that do not deserve a thread

Post by Kez »

I think you can obsess too much about such things!

1- In terms of cable length, it can become more of an issue if you are not using proper 75 ohm termination, as I believe there is some signal reflection which is magnified over longer cable runs. For example if you take "TTL" csync from a Genesis or SNES, and stick a resistor to bring the voltage down, this is not true 75ohm termination and there is still an impedance mismatch. If you need a long cable, it's probably fine to and the degradation will be negligible.. and I certainly wouldn't worry about a 1 ft vs a 3 ft cable, but why use overly long cables if you don't need to? They are just harder to manage. If your chain ends up with a digital output, you're technically better off making the digital cable longer instead. Personally, I tend to go for the most convenient solution and see how it looks, usually it looks good enough for me and I stop there.

2 - People do talk about this loss. Generally the "optimal" solution is for the cable run to be as short as possible from the console to the display. RetroRGB recently released a SCART coupler partially to address this. [Edit: Sorry I didn't fully parse what you were saying - insertion loss is as you say probably a larger concern than cable length but ultimately it should only be something you investigate if you notice issues in your setup.. not something to fret about beforehand]

3 - Many lag writeups will explain that CRTs are considered the baseline for lag, they are essentially drawing the frame as it arrives and it is not possible to produce a signal any faster. Of course they are not truly 0 lag, and the software they are running has inherent lag also, but for the purposes of measuring lag in your display chain, it is safe to consider a direct CRT connection as 0. In terms of longer cables producing lag, this is so negligible as to not be worth thinking about in any reasonable scenario. Think about how many miles of cable you are passing signal through to talk to someone in another country, and you end up with only a few ms of lag (probably mostly due to other factors as well).

4 - Components have varying tolerance, but these circuits are designed with a particular voltage level in mind. Asking "how off-spec can I get before my stuff breaks?" is not a particularly constructive question. Why do you want to go off-spec? Just use proper video circuits. Plenty of superguns can do this, but the gscartsw has this caveat because people have managed to damage them in the past with dodgy superguns.
Last edited by Kez on Sat Dec 12, 2020 4:15 pm, edited 1 time in total.
ajdesmarais
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Re: Questions that do not deserve a thread

Post by ajdesmarais »

Didn't want to make a new thread because everybody and their brother has sync problems at some point, but these are some unique symptoms so hopefully someone can point me in the right direction;

My PVM20M4U has started to lose horizontal sync over RGB upon power up, but I've found if I go into the menu and tweak the video phase value higher, it will restablish sync, even if I return the setting to its initial value afterward, kind of like the amplification of the signal is enough to complete the circuit across some faulty component(s) until the monitor is shut off again.

Additionally, if I'm using something with integrated sync, like a VCR or anything else with composite, I can't seem to establish sync no matter how much I tweak the settings, which would also make sense because that sync signal is much weaker/dirtier.

I know there are schematics, but I suck at reading them. I'm not sure what component of the sync circuit could be responsible for this failure. I had some geometry problems, so I took this as an opportunity to recap the whole deflection board, but the problem still persists. Are there major sync components on the input or neck boards that could be responsible for this? I've come across some info that most or all of the sync is handled by a single IC, but I'll be damned if I can figure out which one.

Any help would be appreciated, thanks dudes.
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Re: Questions that do not deserve a thread

Post by SavagePencil »

Should I be worried about all my old cartridges with battery backups having the batteries leak?
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maxtherabbit
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Re: Questions that do not deserve a thread

Post by maxtherabbit »

NewSchoolBoxer wrote: [*] The loss no one talks about is connecting components together - the interconnections such as SNES to SNES Multiout to Switcher input to output to TV for 4 connections. Not much online about it. One source uses 0.6 * sqrt(frequency in GHz) so 6 MHz is 0.6 * sqrt(0.006 GHz) = 0.05 dB loss per BNC connector: https://www.amphenolrf.com/faq/technica ... specified/
I'm glad you bring up insertion loss. It is a very real issue, and would likely have more effect than cable length in a typical retro setup using coax cables and many various passive adapters. Sticking with one type of connector is best to minimize the quantity of adapters, and impedance controlled connectors are a plus too.
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vol.2
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Re: Questions that do not deserve a thread

Post by vol.2 »

ajdesmarais wrote:Didn't want to make a new thread because everybody and their brother has sync problems at some point, but these are some unique symptoms so hopefully someone can point me in the right direction;

My PVM20M4U has started to lose horizontal sync over RGB upon power up, but I've found if I go into the menu and tweak the video phase value higher, it will restablish sync, even if I return the setting to its initial value afterward, kind of like the amplification of the signal is enough to complete the circuit across some faulty component(s) until the monitor is shut off again.

Additionally, if I'm using something with integrated sync, like a VCR or anything else with composite, I can't seem to establish sync no matter how much I tweak the settings, which would also make sense because that sync signal is much weaker/dirtier.

I know there are schematics, but I suck at reading them. I'm not sure what component of the sync circuit could be responsible for this failure. I had some geometry problems, so I took this as an opportunity to recap the whole deflection board, but the problem still persists. Are there major sync components on the input or neck boards that could be responsible for this? I've come across some info that most or all of the sync is handled by a single IC, but I'll be damned if I can figure out which one.

Any help would be appreciated, thanks dudes.
Looking at that manual shows the sync goes through components in the Q board. (page 74-75) There are caps, diodes and transistor for each input. However, if you are experiencing sync issues on all inputs, then that probably points to a bigger issue. It's unlikely that a single bad component in the input board is going to ruin the sync for all inputs. (but not impossible if the sync circuit is being shorted out or something.

The sync goes through more than one IC. The main IC in the set, IC101, is the UPD78014FYCW-W23 and that would be part of the sync. I guess if that was bad it would screw things up. It's hard to say. The IC is not made anymore, but you may be able to get it through a sony part place. Probably cost a lot to find out if it's the issue.
ajdesmarais
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Re: Questions that do not deserve a thread

Post by ajdesmarais »

vol.2 wrote:
Looking at that manual shows the sync goes through components in the Q board. (page 74-75) There are caps, diodes and transistor for each input. However, if you are experiencing sync issues on all inputs, then that probably points to a bigger issue. It's unlikely that a single bad component in the input board is going to ruin the sync for all inputs. (but not impossible if the sync circuit is being shorted out or something.

The sync goes through more than one IC. The main IC in the set, IC101, is the UPD78014FYCW-W23 and that would be part of the sync. I guess if that was bad it would screw things up. It's hard to say. The IC is not made anymore, but you may be able to get it through a sony part place. Probably cost a lot to find out if it's the issue.
Thanks man. I'll pull up a schematic and try and follow it with the starting points you gave me. I'll look up how to test the components and hopefully that will produce a culprit. I appreciate your input.
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vol.2
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Re: Questions that do not deserve a thread

Post by vol.2 »

ajdesmarais wrote: Thanks man.

NP. Also, clean the connector between Q board and A board very well with Deoxit. Spray it in the holes and insert remove insert remove many times. All of the sync signals travel over that connector.

Unfortunately, these things can be hard to figure out even for someone with the correct equipment. If it gets too hairy, prob best to have it repaired.
ajdesmarais
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Re: Questions that do not deserve a thread

Post by ajdesmarais »

vol.2 wrote:NP. Also, clean the connector between Q board and A board very well with Deoxit. Spray it in the holes and insert remove insert remove many times. All of the sync signals travel over that connector.

Unfortunately, these things can be hard to figure out even for someone with the correct equipment. If it gets too hairy, prob best to have it repaired.
Will do. I've been open to having some kind of professional take a look at it, because while I could probably eventually fix it by doing the random buy-and-replace tactic, the alternative is certainly more comfortable. Shame we're in the middle of the pandemic, but it'd also the only reason I've had time to try and fix it. Thanks!
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NewSchoolBoxer
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Re: Questions that do not deserve a thread

Post by NewSchoolBoxer »

Impractical to test because it would depend on the individual monitor or TV. You would have to look at the schematic and evaluate the circuit and anything upstream from the input to determine the effect of 5V. That would mean pulling datasheets to look at absolute maximum ratings in addition to a holistic evaluation of the sync input in the system.
I agree it's impractical. Studying datasheets is the starting point. Lot of effort but would be desirable to find consumer CRTs that can accept either sync level.

Thanks Kez for the feedback and I needed some criticism! I want to be practical, not excessively thorough. Made me angry of all the resources and datasheets I had to buy a new computer and graphics card with versus what is out there for analog cables (and ADC processing on televisions).

1 - Impedance mismatching is an important point here. Just using an online calculator, matching 470 ohms to 75 results in dB loss of 3.2. That's the difference between Component quality and S-Video on video lines. The sync line handles losses much better but the reflected wave can crosstalk on video.

2 - I get what you're saying about not being proactive in search of a problem if everything looks good as is. Since I want to measure cable quality already from one make to another, chaining connectors to see how much noise is added isn't much more effort. Maybe help SCART coupler sales. I am impressed with RetroRGB science on controller input lag: https://www.retrorgb.com/controllerlag.html

With cables on hand, I need 7 connectors to go from SNES to DVI-A capture card. Could buy a SyncBaby for $65 to reduce to 3 connections but I have to guess if going deeper down the rabbit hole is worth it.

3 - Sure, a somewhat long 2 meter cable line is only 7-10 ns of delay. That's invisible to someone playing a video game. Just hypothetically, I'd predict the sync line trailing RGB lines by 1/2 the wavelength of 15 kHz vertical sync to black out the screen. That would take a delay of 133 µs (133k ns). The delay of the LM1881 sync separator, as I read it, is 65 µs. I just want to be as exact as I can. But this is too far, yeah. Maybe there are edges case where the small things matter, like RGB modding a system already known for sync issues (daty2k1's chart): viewtopic.php?f=6&t=57929&start=180

4 - Good points. Too bad I don't have an interest in supergun measurements and fixes. I got the idea to test for out of spec levels when I read the last page of the manual for my PVM-L2: http://www.broadcaststore.com/pdf/model ... m-20l2.pdf
External Sync spec is:
4.0 Vp-p ± 6 dB, sync negative, usable tri-level sync signal 0.6 Vp-p ± 6 dB
HD signals use the tri-level 0.6 level sync versus bi-level 0.3 for SD. You would know what dB means here but to explain for someone without a circuits background:
The ± 6 dB means an error margin (input tolerance) of ± 75% power, or ± 86% voltage at fixed impedance. Not enough for 0.3 Vp-p CSYNC to work on 4.0 Vp-p, yet it does.
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erik343
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Re: Questions that do not deserve a thread

Post by erik343 »

I have a random question. I am trying to learn about electronics and modding consoles...

What farad capacitor does the PS1 and PS2 have on the chroma (C) signal. I could open them up, but I don't want to do that quite yet. Also, on the stock original NES (no mods), what farad capacitor does the composite video (V) line have?

Thanks.
Erik W.
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kitty666cats
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Re: Questions that do not deserve a thread

Post by kitty666cats »

This is a real random one, but it was always in the back of my mind when I had a Dreamcast & a Toro:

Back when the Toro was new, were many people here (or ANYWHERE) keen on making custom connectors for the Toro so it could be used with other consoles? Obviously the 31kHz switch would be rendered useless, but it seems like it could be a fun little day-project... getting 15kHz RGBS or RGBHV out of any of your consoles via the DE15 out connector, plus still having good ol' SCART on hand, heh.
ldeveraux
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Joined: Thu Mar 01, 2018 10:20 pm

Re: Questions that do not deserve a thread

Post by ldeveraux »

kitty666cats wrote:This is a real random one, but it was always in the back of my mind when I had a Dreamcast & a Toro:

Back when the Toro was new, were many people here (or ANYWHERE) keen on making custom connectors for the Toro so it could be used with other consoles? Obviously the 31kHz switch would be rendered useless, but it seems like it could be a fun little day-project... getting 15kHz RGBS or RGBHV out of any of your consoles via the DE15 out connector, plus still having good ol' SCART on hand, heh.
They even sold the connections themselves at one point. Then they realized they could make more money by selling full boxes instead of small upgrades, so they stopped. You can always make your own, but there's a reason my Toro is sitting in a box unused.
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