How to use SCART for our hobby

[Zebidee]

If you have a good quality TV screen, your best bet is to get a generic chassis to fit it rather than trying to invent RGB inputs.  Guaranteed to work (if your screen is good), and no stuffing around with unknown electronics this way.  Jomac sell them at reasonable prices: www.jomac.net.au

[ArcadeBliss]

Seeing as how this is the post regarding using scart, I will stretch out my feelers here to see if anyone is intrested in this. In the pictures below you will find a vga-2-scart circuit that sends out the correct composite sync signal for use with Guncon2. It nicely fits in a scart connector housing 

Let me know if you are instrested in something like this. The amount of answers will determine if it makes sense to make a batch of these.

.....Edited to refelect Guncon 2 and not 3...

[Zebidee]

a vga-2-scart circuit that sends out the correct composite sync signal for use with Guncon2/3. It nicely fits in a scart connector housing 

Hi, that is fascinating.  Did you do that yourself? The resistors are tiny ....

What is the correct composite sync signal for a Guncon 2/3, and how can we apply that to other applications? For example, does this convert +/- sync signals so that you can connect to a normal monitor with composite sync in, without worrying about polarity?

[ArcadeBliss]

In my experience, the polarity needs to be negative to work correctly. This circuit is the another version of the circuit from this website: http://xoomer.virgilio.it/guncon2/VideoCon2.htm

I did not do them myself. I have a friend who hat "spare" space on another projekt at his job. He let me know if there is enough demand he can make a dedicated run to have more created.

[Zebidee]

In my experience, the polarity needs to be negative to work correctly. This circuit is the another version of the circuit from this website: http://xoomer.virgilio.it/guncon2/VideoCon2.htm

I did not do them myself. I have a friend who hat "spare" space on another projekt at his job. He let me know if there is enough demand he can make a dedicated run to have more created.

The key advantage of this bit over circuitry, compared to just twisting the sync wires, is that you can use positive or negative Horz & vertical sync. The circuitry converts it to a simple composite sync. Which is the same outcome as twisting the wires if you use negative for both syncs.

 

 

[tomoprime]

Hi Guys - just joined after reading this thread which looks very helpful.

I have a MV1C pcb and was thinking of wiring the Jamma into a scart hookup because of the RBG. I live in the US and would like to get a scart tv or rgb monitor. Of course there's all kinds of ways to add video encoders with jrok or Neo Bitz, or VGA upscale, but I'd like to get that arcade monitor look without the insides being exposed.

1) What's an economical way to use scart with scanlines ? I guess buy a monitor but which?
   - not too big, even flat pannel if price is right.

2) Or convert from scart / RGB source using external devices, no scan lines.

I doubt these are cheap way outs but after seeing these on ebay it makes me wonder if this stuff works.
Hard to say if these are UK or JP scart converters. Plus where are the encoder chips if adapters are so small?

Just type scart in ebay search
http://cgi.ebay.com/RGB-Scart-to-3-RCA-S-Video-Audio-AV-TV-Adapter-9711_W0QQitemZ200329775478QQcmdZViewItemQQptZLH_DefaultDomain_0?hash=item200329775478&_trksid=p3286.c0.m14&_trkparms=72%3A1234%7C66%3A3%7C65%3A12%7C39%3A1%7C240%3A1318%7C301%3A0%7C293%3A1%7C294%3A100

http://cgi.ebay.com/Scart-to-yPbPr-Connector-for-DM500_W0QQitemZ110326742418QQcmdZViewItemQQptZLH_DefaultDomain_0?hash=item110326742418&_trksid=p3286.c0.m14&_trkparms=72%3A1234%7C66%3A3%7C65%3A12%7C39%3A1%7C240%3A1318%7C301%3A1%7C293%3A1%7C294%3A100

P.S I own a SUN GDM 20D10 monitor with vga adapter but doubt it can step down to 15KHZ

[Zebidee]

I'm not sure exactly what you really want to do, but JAMMA provides RGB input from a PCB to an arcade monitor already.

If you want to make a JAMMA->SCART TV setup, then you need to use resistors on the RGB lines. Arcade PCBs usually output the signals at a higher voltage.  Try using 75 ohm resistors on the RGB lines, but leave the sync alone.

[tomoprime]

Sorry for being unclear.

I have a pcb with no monitor.

I want to buy a monitor that is inclosed in it's own case.

It seems people are using scart to do this. I live in the US and don't have a scart tv.

So I can do two things.

1) get a scart based, or rgb arcade based monitor. I don't know where to begin here. Please provide feedback.

2) buy a converter, either using scart to something or rgb to something. I gave some examples from ebay. Basicly just give me examples of how I can hook this up to something if option 1 doesn't work above. Yeah there goes my scanlines.

[Zebidee]

http://cgi.ebay.com/Scart-to-yPbPr-Connector-for-DM500_W0QQitemZ110326742418QQcmdZViewItemQQptZLH_DefaultDomain_0?hash=item110326742418&_trksid=p3286.c0.m14&_trkparms=72%3A1234%7C66%3A3%7C65%3A12%7C39%3A1%7C240%3A1318%7C301%3A1%7C293%3A1%7C294%3A100[/url]

P.S I own a SUN GDM 20D10 monitor with vga adapter but doubt it can step down to 15KHZ

I personally can't help you in the US, I am in Australia. My main suggestion would be to look for a good-quality Euro brand like Loewe, Grundig, Telefunken ..... These TVs come SCART standard, and they are less likely to change the input specs for (formerly) expensive models. So there is a chance that they are still SCART in the US.

I have seen Euro people on this forum offer to send shiploads of SCART TVs to their unfortunate cousins across the lake.

I had a look at this adaptor:

http://cgi.ebay.com/Scart-to-yPbPr-Connector-for-DM500_W0QQitemZ110326742418QQcmdZViewItemQQptZLH_DefaultDomain_0?hash=item110326742418&_trksid=p3286.c0.m14&_trkparms=72%3A1234|66%3A3|65%3A12|39%3A1|240%3A1318|301%3A1|293%3A1|294%3A100

The adaptor looks like it does genuine RGB->component conversion, and it is cheap, so why not give it a go and tell us all how it worked!

[rygar_70]

Hi guys

I need help big time!

I have read all your forum discussions, and followed all the links regarding scart converting to arcade.  I built two scart connectors with & without 100 ohm resistors, also linked pin 16 to 20, and also connected the 8 pin to 12+ and many many others combos as well - with minimal luck, to the place I'm at the moment where I get an image on the screen - it's black/grey with embossed graphics?  NO COLOUR!!

Can anyone help?  I'm using a Teac CT M201 51cm TV (is this the problem?)

Please advise.

I'm looking forward towards anyones prompt response in this matter, before I sink my foot into this project.

Mick

[Zebidee]

Hi guys

I need help big time!

I have read all your forum discussions, and followed all the links regarding scart converting to arcade.  I built two scart connectors with & without 100 ohm resistors, also linked pin 16 to 20, and also connected the 8 pin to 12+ and many many others combos as well - with minimal luck, to the place I'm at the moment where I get an image on the screen - it's black/grey with embossed graphics?  NO COLOUR!!

Can anyone help?  I'm using a Teac CT M201 51cm TV (is this the problem?)

Please advise.

I'm looking forward towards anyones prompt response in this matter, before I sink my foot into this project.

Mick

In my experience, TEAC TVs are the most tiresome SCART TVs to deal with.  However, you should still be able to get it to work properly. This is how I got a similar TV, a 51cm TEAC CT-something, to work under VGA-SCART you will need to build a fully-featured VGA-SCART cable with :

1)  Molex 5v (red) + 100 ohm resistor  => 2v to SCART pin 16
2)  Molex 12v (yellow) => SCART pin 8
3) Molex Ground (both black ones) => SCART pin 18

Then apply power to the TEAC TV and press channel up (+) button. This last step might be different for you, but just turn on the TV and change the channel to AV mode. The cable should auto-select this for you, but when I did this and tested it the TEAC TV would not stay in AV mode unless 12v was also present at SCART pin 8. So you may have to manually change channels.

If this still doesn't work then you might need to check your cable thoroughly.

The only other thing that may happen is that some cheap SCART TVs may only have the composite video input
enabled, although you probably wouldn't get any picture at all if this was the case.  I have only seen this once with a Goldstar TV, but bear in mind that TEAC is also at the cheaper end of the scale (but not as cheap & nasty as Goldstar).

[rygar_70]

Tks Zebidee for getting back so quick.

Funnily enough, I did grab this cheap & nasty Teac at my local "Crime Converters" or "cashies" for $20.  And just to add injury to insult, the tube happens to be a Goldstar! lol!

I will try this tonite - sounds like an all-nighter here for me (a novice at soldering) but it seems straight forward enough!

Thanks champ!

Mick

[Quinny]

I'd just like to let people know that you definitely need a RGB enabled SCART on the TV.

I got a 68cm NEC TV for free but had to pay $80 to repair it. It would make a great arcade monitor. It only has one scart input and that is for s-video.

I have a set top box which can output composite, component, RGB and s-video. I hooked up the set top box and can use any output signal and the TV will detect it, though composite, component and RGB all look the same, so I suspect that the TV is converting the signal to something common.

I thought this would allow an RGB signal to display on it but using this cable there is no colour detection and no picture. I know my cable works because I can use it on our widescreen TV.

I think my best option now is to see if I can swap this TV for a similar one with a RGB scart input.

[Zebidee]

I'd just like to let people know that you definitely need a RGB enabled SCART on the TV.

I thought this would allow an RGB signal to display on it but using this cable there is no colour detection and no picture. I know my cable works because I can use it on our widescreen TV.

This is surprising as I have never had any probs with using Philips 68cm TVs. Where are you?

You might find that your set-top box is sending composite video as well as RGB/Component signals, and that is what your TV is picking up and locking onto. You may find that you can get it to recognise the RGB signals. Check the service menu, see if there is a option on what to do with AV input (set to RGB!)

Also, I don't know what your VGA-SCART cable really does. In particular, make sure that your cable has voltages at pins 8 (12v) and 16 (2v). Pin 16 tells the TV RGB mode. Pin 8 tells the TV what mode to be in (usually you will want AV-RGB).

Cheers, Zeb

[Zebidee]

I got a 68cm NEC TV for free but had to pay $80 to repair it. It would make a great arcade monitor.

The other thing you can do is keep the Philips screen (ditch the rest of the TV) and buy an arcade monitor chassis to suit from Joey at www.jomac.net.au.

Many (newer) Philips TV screens are very good quality, and make excellent arcade monitor screens. Their screens are used by top TV European brands.

[Quinny]

This is surprising as I have never had any probs with using Philips 68cm TVs. Where are you?

I am in Perth, West Australia. I am not sure where Philips comes into this, are they part of NEC?
Here is a link to the user manual for the TV: http://www.nec.com.au/docs/FS68V81_Instruction_Manual.pdf. It's the FS-68T90.

You might find that your set-top box is sending composite video as well as RGB/Component signals, and that is what your TV is picking up and locking onto.

This is what I suspect is happening.

You may find that you can get it to recognise the RGB signals. Check the service menu, see if there is a option on what to do with AV input (set to RGB!)

I found what seems to be how to access the service menu here but that doesn't work on the TV.
I could maybe get the TV repair man to try this.

Also, I don't know what your VGA-SCART cable really does. In particular, make sure that your cable has voltages at pins 8 (12v) and 16 (2v). Pin 16 tells the TV RGB mode. Pin 8 tells the TV what mode to be in (usually you will want AV-RGB).

Cheers, Zeb

I have tried both the pin20 -> pin16 link and using a AA battery to pin16. They don't make any difference. I didn't use pin8 because I can use the remote or the TV itself to choose AV1.

The other thing you can do is keep the Philips screen (ditch the rest of the TV) and buy an arcade monitor chassis to suit from Joey at www.jomac.net.au.

Many (newer) Philips TV screens are very good quality, and make excellent arcade monitor screens. Their screens are used by top TV European brands.

The chassis that are $120 or $250? I don't know much about TVs. How would a new chassis help?

The screen does seem to be of a good quality and even the TV repair man commented that it was a very good TV.

Thanks for your help Zebidee.

[Zebidee]

This is surprising as I have never had any probs with using Philips 68cm TVs. Where are you?

I am in Perth, West Australia. I am not sure where Philips comes into this, are they part of NEC?
Here is a link to the user manual for the TV: http://www.nec.com.au/docs/FS68V81_Instruction_Manual.pdf. It's the FS-68T90.

I dunno where I got the Philips from either ... I answered pretty quickly before going to work, maybe my eye scanned it in from earlier in the thread .... ooops!

You may find that you can get it to recognise the RGB signals. Check the service menu, see if there is a option on what to do with AV input (set to RGB!)

I found what seems to be how to access the service menu here but that doesn't work on the TV. I could maybe get the TV repair man to try this.

That is not a service manual!  That is a user manual. They are different things. Service manuals are only for official techs and access is usually restricted, although I have found many on the web (try http://eserviceinfo.com/). You can ask your service guy to help.

Also, I don't know what your VGA-SCART cable really does. In particular, make sure that your cable has voltages at pins 8 (12v) and 16 (2v). Pin 16 tells the TV RGB mode. Pin 8 tells the TV what mode to be in (usually you will want AV-RGB).

Cheers, Zeb

I have tried both the pin20 -> pin16 link and using a AA battery to pin16. They don't make any difference. I didn't use pin8 because I can use the remote or the TV itself to choose AV1.

Personally, I think that the battery way is a bit iffy especially as the battery voltage will run down pretty quickly. The pin20 -> 16 trick works for some, not all.

The best way for you to get a reliable 2v at pin 16 is to take 5v from the PC power supply and put a 100ohm resistor on it.

You may NEED to use pin 8 as well to get your TV into the right AV-RGB mode.

Some of the TVs I have done this with will ONLY work if you have 2v at pin 16 and 12v at pin8.

This could well be your issue. Make a cable with a molex connector to get the 5v & 12v from the PC. [edit: and attach one molex black ground lead to pin 18]

The other thing you can do is keep the Philips NEC screen (ditch the rest of the TV) and buy an arcade monitor chassis to suit from Joey at www.jomac.net.au.

The chassis that are $120 or $250? I don't know much about TVs. How would a new chassis help?

You'd need a $250 chassis for a 68cm tube. What you would do is de-case the TV, detatch the chassis, and throw everything out except for the tube (and the attached degaussing coil & earth lead). Buy a new chassis from Jomac at attach. Voila! You have a "new" quality arcade monitor!

www.Jomac.net.au is based in Perth so run on down to 95A Carr Street and introduce yourself. They guys down there are friendly and will tell you all you need to know. Tell them I sent you (except that they won't know who Zebidee is that is obviously not my real name!    )

Thanks for your help Zebidee.

No wukkas! Always happy to help a mate, especially an Aussie.

[Quinny]

I found what seems to be how to access the service menu <here> but that doesn't work on the TV. I could maybe get the TV repair man to try this.

That is not a service manual!  That is a user manual. They are different things. Service manuals are only for official techs and access is usually restricted, although I have found many on the web (try http://eserviceinfo.com/). You can ask your service guy to help.

That link I posted above goes to a service tech's page where he wrote the code he used to access the service mode on the same model TV as the one I have. I couldn't get that to work though.

Personally, I think that the battery way is a bit iffy especially as the battery voltage will run down pretty quickly. The pin20 -> 16 trick works for some, not all.

The best way for you to get a reliable 2v at pin 16 is to take 5v from the PC power supply and put a 100ohm resistor on it.

You may NEED to use pin 8 as well to get your TV into the right AV-RGB mode.

Some of the TVs I have done this with will ONLY work if you have 2v at pin 16 and 12v at pin8.

This could well be your issue. Make a cable with a molex connector to get the 5v & 12v from the PC. [edit: and attach one molex black ground lead to pin 18]

I was hoping not to need to do this. I will need to get a resistor, so I will try it tomorrow and let you know how it goes.

You'd need a $250 chassis for a 68cm tube. What you would do is de-case the TV, detatch the chassis, and throw everything out except for the tube (and the attached degaussing coil & earth lead). Buy a new chassis from Jomac at attach. Voila! You have a "new" quality arcade monitor!

www.Jomac.net.au is based in Perth so run on down to 95A Carr Street and introduce yourself. They guys down there are friendly and will tell you all you need to know. Tell them I sent you (except that they won't know who Zebidee is that is obviously not my real name!    )

Hahahah thanks Zebidee. I think for that price I could get a new TV with an easier scart connection to work with. Is there any other benefit to using their chassis?

[sevenleaf]

I am about to make my own VGA to SCART cable for my Sony 27" CRT (although I may have to house it in a box as I don't think I can get it small enough to fit within the SCART casing). I like the simplicity of the one on the first post, but I would like to add in a function to protect the TV during boot up.

Has anyone on here either built or have any comments on this circuitry?





Source: http://members.optusnet.com.au/eviltim/scart.htm

[Zebidee]

I found what seems to be how to access the service menu <here> but that doesn't work on the TV. I could maybe get the TV repair man to try this.

That is not a service manual!  That is a user manual. They are different things. Service manuals are only for official techs and access is usually restricted, although I have found many on the web (try http://eserviceinfo.com/). You can ask your service guy to help.

That link I posted above goes to a service tech's page where he wrote the code he used to access the service mode on the same model TV as the one I have. I couldn't get that to work though.

Sorry about that, seems again I'm getting lost in this thread and reading/responding a bit quickly ...

So what your article says is:

"NEC Technical Support thankfully deduced that the set was locked into the "HOTEL" mode. This function is to protect hotel TV installations from the prying hands of inquisitive guests. To release it, you have to press "Delete", "Move", "Skip" and "Operate".

Finally, to access the Service Mode, you must first select program 91 and set "Sharpness" to minimum, then very quickly press "Red", "Green" and "Menu" in turn, then "OK".

This is for a different model NEC, it might work for your NEC:
"Select DISPLAY MODE. Press PROCEED.
Press and hold RESET. Then simultaneous
press + & -. 'Warning Entering Service Menu…'
appears. Press PROCEED for enter."

You'd need a $250 chassis for a 68cm tube. What you would do is de-case the TV, detatch the chassis, and throw everything out except for the tube (and the attached degaussing coil & earth lead). Buy a new chassis from Jomac at attach. Voila! You have a "new" quality arcade monitor!

www.Jomac.net.au is based in Perth so run on down to 95A Carr Street and introduce yourself. They guys down there are friendly and will tell you all you need to know. Tell them I sent you (except that they won't know who Zebidee is that is obviously not my real name!    )

Hahahah thanks Zebidee. I think for that price I could get a new TV with an easier scart connection to work with. Is there any other benefit to using their chassis?

The main benefit I have found is that the new arcade chassis is more reliable and usually better picture than an old TV. Joey will give you telephone support for any issues you have, and will accept the chassis back for repair if there are any problems (usually free for recent purchases, and cheap otherwise). If something stuffs up in your TV. you are pretty much tied to taking it to a TV repair guy, and those are getting harder to find and more expensive. I have gone the arcade monitor option when I have had problems with TVs previously. Better than agonising over repairs to esoteric and obsolete electronics.

[Zebidee]

I am about to make my own VGA to SCART cable for my Sony 27" CRT (although I may have to house it in a box as I don't think I can get it small enough to fit within the SCART casing). I like the simplicity of the one on the first post, but I would like to add in a function to protect the TV during boot up.

Has anyone on here either built or have any comments on this circuitry?





Source: http://members.optusnet.com.au/eviltim/scart.htm

1) Seems that you don't need to link the 12v from SCART pin 8 -> R2 -> pin 16 at all.

2) What does "enable input" go to? is that taking 5v then? To power a JPAC?

3) you don't need 150 ohms for R1, 100 ohms should be perfect.

[Quinny]

Hello,

OK I have configured my cable thus:

VGA ground, VGA 6, 7 and 8 (RGB ground) all twisted together to SCART 17.
VGA 1, 2 and 3 to SCART 15, 11 and 7 respectively.
VGA 13 and 14 twisted together to SCART 20.
Molex (red) 5V with 100 Ohm 1W 5% tolerance resistor to SCART 16.
Molex (black) ground twisted together to SCART 18.
Molex (yellow) 12V to SCART 8.

This cable still does not work on my NEC TV but works lovely on our widescreen (which is a Sansui). The molex cable made no difference to the result I was getting with the pin 20->16 or the AA battery.

What I can see with the NEC TV is that it detects the H sync + V sync (because the screen stops scrolling) but there is just no picture at all and no colours are detected.

I guess the only thing left to try with this TV is to access the service menu and see if there's an option to accept RGB.

Otherwise I will see if I can trade it for a similar sized one which has the right scart plug, or save up my money and get an arcade chassis as Zebidee mentions.

This is for a different model NEC, it might work for your NEC:
"Select DISPLAY MODE. Press PROCEED.
Press and hold RESET. Then simultaneous
press + & -. 'Warning Entering Service Menu…'
appears. Press PROCEED for enter."

Thanks for trying but I don't have those options available.

The main benefit I have found is that the new arcade chassis is more reliable and usually better picture than an old TV. Joey will give you telephone support for any issues you have, and will accept the chassis back for repair if there are any problems (usually free for recent purchases, and cheap otherwise). If something stuffs up in your TV. you are pretty much tied to taking it to a TV repair guy, and those are getting harder to find and more expensive. I have gone the arcade monitor option when I have had problems with TVs previously. Better than agonising over repairs to esoteric and obsolete electronics.

Thanks. If I still have the TV and enough funds in a couple of months I will definitely look into this.

Thanks for all your help Zebidee!

[Zebidee]

That's real bad luck and I'm sorry to hear that, Quinny. Having a SCART TV that doesn't work in RGB. Gotta say that is pretty rare (I saw it just once before with a "Goldstar" branded TV). You should have better luck with another SCART TV if you can find one - at least you know that the cable is perfect!

[sevenleaf]

I am about to make my own VGA to SCART cable for my Sony 27" CRT (although I may have to house it in a box as I don't think I can get it small enough to fit within the SCART casing). I like the simplicity of the one on the first post, but I would like to add in a function to protect the TV during boot up.

Has anyone on here either built or have any comments on this circuitry?





Source: http://members.optusnet.com.au/eviltim/scart.htm

1) Seems that you don't need to link the 12v from SCART pin 8 -> R2 -> pin 16 at all.

2) What does "enable input" go to? is that taking 5v then? To power a JPAC?

3) you don't need 150 ohms for R1, 100 ohms should be perfect.

Thanks Zebidee for taking the time to reply.

1) I was wondering the same - I think the R2 link is only there as the PIC circuit is optional.

2) I think it's the link between the 2 circuits (because the PIC is optional)

3) Cheers

I have emailed the guy who designed the circuits to see if he can shed any light on this. Just got to wait for the PIC programming unit and the other components to arrive and then I can crack on with making it

[Zebidee]

Sevenleaf, you should have a look at the tiny PCB board member Arcadebliss posted earlier in this thread.

Another way to auto-cut the high-frequency signals without using as PIC programmer is to use a JPAC. JPAC will automatically cut out anything not 15khz (or 25khz), and can automatically cut 31khz into two 15khz signals (which is why some people say that they can see two screens when their Soft15khz or whatever isn't working properly).

If you run JPAC-SCART then you must also put 75ohm resistors on the R-G-B signals, otherwise they are too bright (JPAC voltages are higher, designed for arcade monitors and this would not be good long-term for your TV). Sync is fine as-is. However, 3 75 ohm resistors (6 cents each!) and a JPAC is a lot easier than making that circuit you showed us earlier, especially if you are already ising the JPAC as a keyboard interface and/or LED controller.

[SailorSat]

Sorry for bumping this back up

I just noticed that several of my AMIGA-to-SCART cables I have flying around here have +5v wired directly to Pin 16, and +12V wired to Pin 8, and they all work fine with my pretty old Grundig TV.


So I got a little curious.
I remember I've seen several SCART pinouts that state Pin 16 only has an input range up to 3V, while others say 5v.

So I've started to fool around with several (older) TVs over here.

Actually it seems you don't need +12V on Pin 8 and you don't need +5V either.
EVERY single TV I've tried works fine WITHOUT Pin 8 connected to anything.
The only "use" of it is to switch between a FORCED 16/9 or 4/3 mode. Some TVs also power on and switch to channel AV by themself if you supply power there.


Also every single of those TVs worked fine with +5V feed to Pin 16 instead of just 3V.
None of the blew up or something like that.


Conclusion... Though it may not work with every single SCART TV out there, the absolut simplest VGA-SCART cable would be:

Code: [Select]

VGA - SCART
 1  -  15   R
 2  -  11   G
 3  -   7   B

 6  -  13   R-GND
 7  -   9   G-GND
 8  -   5   B-GND

13  -  20   Sync
14  -  20   Sync

 5  -  17   GND

 9  -  16   RGB-Switch
I've modified my VGA-SCART cable that way and have yet to find a TV that does not work.

Also a friend pointet out that you can connect Pin 19 (Composite Out) to Pin 16, as the Composite Video has a signal level of 1V, which also should be enough to switch to RGB mode.
However I haven't yet tried that.

[Zebidee]

Hi Sailor! Yes, you are pretty much right there about the no real need for 12v to pin 8. However, it does help to have the TV auto-switching to AV mode. What it comes down to is that, in most cases, you just need to make a simple cable that does what you need it to rather than adding on too many bells and whistles.

The only TVs that I have absolutely needed 12v to pin 8 for are TEAC TVs, and maybe AKAI but I'm not 100% sure.   Oh, and there was one Sony PVM2730 I had once that had something wrong with the AV mode selector, so I used the 12v option.

The 5v to VGA pin 9 is only supported by some video cards, which includes ATI (& ArcadeVGA). And many VGA cables (e.g. recycled from old monitors, & even some VGA extension cables) do not even have a pin 9, which makes things a bit trickier again.

In many cases I dispense with the 5v as well, and just link SCART pin 20 to pin 16 for RGB mode activation. This works absolutely fine in 80% of cases and is really simple to make, no power inputs and no resistors or anything like that.

What brands of TVs were you testing?

[SailorSat]

2 Grundig (one older 50Hz and a newer 100Hz one)
1 Thompson (rear projection)
1 Blaupunkt (I actually was suprised that ancient piece had a scart socket!)
several others as iirc one universum and once orion

[Zebidee]

2 Grundig (one older 50Hz and a newer 100Hz one)
1 Thompson (rear projection)
1 Blaupunkt (I actually was suprised that ancient piece had a scart socket!)
several others as iirc one universum and once orion

Directly linking SCART pin 20 -> 16 should most likely work well for the Grundigs, Thompson and Blaupunkt, even the 100mhz Grundig. I don't know about the universum & orion brands though.

[sinkhead]

Hi,

Sorry if I'm being dim, but why is pin 18 (Composite video input ground) connected to the Molex return?

Pin 14 and the SCART casing are the return for the two currents coming from the Molex plug.

Many thanks.

[Zebidee]

Hi,

Sorry if I'm being dim, but why is pin 18 (Composite video input ground) connected to the Molex return?

Pin 14 and the SCART casing are the return for the two currents coming from the Molex plug.

Many thanks.

You're looking at some other pinout, I think, and not the one that we are referring to,(or perhaps confusing the SCART output pins for the input pins).

Composite video ground = SCART pin 17
RGB blanking ground = SCART pin 18

Look here for more info: http://pinouts.ru/Home/Scart_pinout.shtml

[sinkhead]

Ah, thanks. Things make much more sense now. I was referring to the pinout on Wikipedia, by the way.

[technocop]

Hi Guys,

I knocked together this lead, and I think it's sort of working.

The colours all look fine, but the screen is constantly "rolling".

When I had my arcade monitor working, and I had a rolling screen, I would adjust the vertical and horizontal pots to get a steady image. This *looks* like the same issue?

Is there anything I can do about this, can I make similar adjustemts in the tv's service mode?

It's an old Toshiba (1721TB), I have no idea how to get into service mode. Google wasn't much help. Anyone know where I might find out??

[Zebidee]

What is your video input source?

Assuming your software is outputting the sync correctly, it sounds like your cable's vertical sync isn't connected properly.

Connect VGA 13 + 14 (hsync + vsync, twist together) to SCART 20

Make sure that all grounds are grounded, esp. VGA 10 (sync gnd).

[technocop]

duhhh...

I hadn't wired up pin 14 (didn't read all the posts here carefully), all working now, thanks

The interlaced modes don't look as good as my old arcade monitor, but what you said in my other thread was spot-on, it looks very nice indeed with my arcadeVGA. Pleased with the results, much easier and cheaper than getting hold of a new arcade monitor.

Only problem is that some modes get lines cut off. And I'm also missing a very thin strip down the left of the screen I presume I can adjust the geomety in the service menu, but I have no idea how to get to it!

Would anyone here know where I could find this information?

[Zebidee]

Try this (below), which I've seen for other Toshiba models. But don't ask me what it means, except that by "keyboard" I *guess* they mean the remote. One usually needs an original remote to get access to service modes - universal remotes usually don't cut it, although you might get lucky

"Press 'MUTE' button. Press and hold 'MUTE'
button and press 'MENU' on local keyboard."

[technocop]

Try this (below), which I've seen for other Toshiba models. But don't ask me what it means, except that by "keyboard" I *guess* they mean the remote. One usually needs an original remote to get access to service modes - universal remotes usually don't cut it, although you might get lucky

"Press 'MUTE' button. Press and hold 'MUTE'
button and press 'MENU' on local keyboard."

I don't have the original remote, but I'm pretty sure it didn't have a "menu" button.

I have a Logitech Harmony, so I reckon I could I could probably access it...IF I knew what the commands were...

cheers anyway...

[Em]

Hello,

I've got an ArcadeVGA card hooked up to my TV via a hand made VGA to SCART cable. The ArcadeVGA is the PCIe (Radeon HD2400 based) one. The TV is a really old Sony KV-25F1U. The TV does support an RGB signal. The PC is running XP SP3. The cable started off as an Ultimarc VGA breakout cable and it seems to work OK. The Windows boot screens display correctly and I can get a Windows desktop displayed at 640x480 interlaced without a problem. But I'm having trouble getting some of the other resolutions working in Windows. Specifically the non-interlaced resolution of 640x288. When I use quickres to switch to 640x288 I get a picture but with a very fast vertical scroll. It looks like an vsync problem. Here is how my cable is wired up:

VGA      SCART
1   ->   15
2   ->   11
3   ->   7
6   ->   13
7   ->   9
8   ->   5
10   ->   17
13,14   ->   20
5   ->   21

PC Power         SCART
+12v   ->         8
+5v   ->   100Ohms   ->   16
0v   ->         18

Audio      SCART
Left   ->   6
Ground   ->   4
Right   ->   2

So I have both VGA sync pins (13 and 14) connected to SCART pin 20. I tried some of the other resolutions out too (all in Windows at the moment not MAME). 240x240 worked OK, as did 256x240. When I went up to 256x256 though, I just got a black screen and had to reboot into XPs VGA mode. I've also tried rebuilding Windows and reinstalling the AVGA drivers. Still the same thing. One thing on the cable I wasn't sure about was connecting VGA pin 5 to SCART pin 21. Both are grounds. I've tried with those pins connected and disconnected and it doesn't make any difference.

So I'm at a bit of a loss as to what to try next. Hence this post. I'm after some advice! Does this sound like a VGA-SCART cable problem? Or a Windows driver problem? Maybe I've got a duff ArcadeVGA card? Or maybe it's the ancient TV I'm trying to use? Or have I just done something really daft in my wiring above!? Any thoughts gratefully received. This forum has been extremely useful in getting to this point. And thanks for reading this far. (Sorry for the long post!)

Em.

[Zebidee]

Em

Sorry for the late post.

From the way you describe it, the SCART cable seems fine. If it works at one res it will work for another. I think that your problem is that your TV is old, or at least doesn't accept a large range of sync frequencies. Every TV is a bit different. Some older TVs don't like doing > 240 lines. I have an old Sony TV that won't do > 240 lines but does interlaced modes like 640x480, and a Sony 21" professional video monitor that does 640x288 flawlessly but just won't do 640x480!

Remember that 640x480 is an interlaced mode, and 640x288 is non-interlaced - Your TV is capable of 240 vertical lines (240x2=480) and does interlacing, but it seems that it can't do 288 vertical lines without scrolling (have you tried a V-Hold knob?).

cheers, Zeb

[Zebidee]

.