Solution for external Flicker fixer?
- Thread starter Harrison
- Start date
- Replies 814
- Views 312618
@Harrison, Weird about the VGA in, it has all the correct pins placements and is just wired inline with P11 and P3. And also straight from the supplied cable you should get something especially how you've wired it up correct. It does suggest in the manual you try the V sync wire if you are having problems (Yellow wire) but that doesn't make any logical sense. For me with the Neo Geo I had no issues and that has a dedicated Sync out as well and I connected it to Grey as you have (no need to strip from Comp Video).
To be sure: -
Amiga RGB - GBS (P11) - GBS (VGA P10) - GBS (P3)
3 - 8 - 1 - R
4 - 7 - 2 - G
5 - 6 - 3 - B
10 - 5 or 4 - 13 - S
16 - 1 or 2 - 10 - GND
Another thing to try is setting up the GBS within the inbuilt menu. I had to auto config before I got a steady picture for the first time. (You have to navigate a little to find the English option as it defaults in Chinese, but its not too hard to find). Then change the resolution to 1024 x 768 if its not there already. And Auto set again. You may also need to auto set the monitors your plugging into.
Another thing could be to try adjusting the 3 yellow pots on the board, you might have had the misfortune of receiving your board not setup correctly on RGB. As a guide mine all point to the right if looking at the board with P10 and the Component sockets towards the bottom. They measure approx 66 ohms each. I never had to adjust mine though.
My limit now though, is that i've not used my GBS for my Amiga yet, only Neo Geo, so hopefully some of the other guys that are using theirs for Amiga can help better.
To be sure: -
Amiga RGB - GBS (P11) - GBS (VGA P10) - GBS (P3)
3 - 8 - 1 - R
4 - 7 - 2 - G
5 - 6 - 3 - B
10 - 5 or 4 - 13 - S
16 - 1 or 2 - 10 - GND
Another thing to try is setting up the GBS within the inbuilt menu. I had to auto config before I got a steady picture for the first time. (You have to navigate a little to find the English option as it defaults in Chinese, but its not too hard to find). Then change the resolution to 1024 x 768 if its not there already. And Auto set again. You may also need to auto set the monitors your plugging into.
Another thing could be to try adjusting the 3 yellow pots on the board, you might have had the misfortune of receiving your board not setup correctly on RGB. As a guide mine all point to the right if looking at the board with P10 and the Component sockets towards the bottom. They measure approx 66 ohms each. I never had to adjust mine though.
My limit now though, is that i've not used my GBS for my Amiga yet, only Neo Geo, so hopefully some of the other guys that are using theirs for Amiga can help better.
I have the grey to pin 10, but don't have all the grounds joined. Will do that.
For the VGA I'm going to find my proper a4000 VGA adapter and try that again as I'm wondering if the adapter I've been using is actually ok.
For the VGA I'm going to find my proper a4000 VGA adapter and try that again as I'm wondering if the adapter I've been using is actually ok.
Correct me if i'm wrong, but I thought all the necessary grounds were connected on the Amiga mainboard at the RGB port anyway... its been a while since I last looked so I could be wrong, hence only needing to drag 1 GND point out (I used Sync Ground to be consistent 
) If you have a multimeter. Beep out the GND pins from Amiga RGB port and double check that the R G B and S GND's are all connected. If they are you don't need to join the GND's up on the plug, just select one to wire up. If they aren't connected, then do as John suggests as you do indeed need GND for the three colours as well as CSYNC.
If I were you Harrison, I'd try and get this working from the 23 Pin RGB port directly first. Omit the VGA adapter for now and use the supplied wires. I made a small extension to my Neo Geo SCART cable. If you have an Amiga SCART cable, pop it open at the SCART end and solder the 5 wires from the GBS to it. Then you get a longer cable to play with too.
EDIT
Pinouts for SCART to RGB Amiga: -
http://wired.hard.ru/data/pin_AmigaScart.shtml
) If you have a multimeter. Beep out the GND pins from Amiga RGB port and double check that the R G B and S GND's are all connected. If they are you don't need to join the GND's up on the plug, just select one to wire up. If they aren't connected, then do as John suggests as you do indeed need GND for the three colours as well as CSYNC.If I were you Harrison, I'd try and get this working from the 23 Pin RGB port directly first. Omit the VGA adapter for now and use the supplied wires. I made a small extension to my Neo Geo SCART cable. If you have an Amiga SCART cable, pop it open at the SCART end and solder the 5 wires from the GBS to it. Then you get a longer cable to play with too.
EDIT
Pinouts for SCART to RGB Amiga: -
http://wired.hard.ru/data/pin_AmigaScart.shtml
Last edited:
I've beeped out the ground pins at the Amiga and they are definitely all connected together, so that means only one is needed.
I've also beeped out all the pins from the Amiga connector on the GBS8220 cable and they are all correctly beeping to the right places at the other end, so that should be OK.
But still not working. I'm seeing the Amiga display flicker into view, but scrambled for a few seconds and then it changes to no signal. It also seems that after the GBS8220 has been switched on I can only control its menu for minute maybe and then it just displays the No signal and I can't make the menu come up unless I switch it off and on again.
I'm now wondering if I have a faulty GBS8220. What do you think?
What could I test on that itself to see if it is working correctly?
I've also beeped out all the pins from the Amiga connector on the GBS8220 cable and they are all correctly beeping to the right places at the other end, so that should be OK.
But still not working. I'm seeing the Amiga display flicker into view, but scrambled for a few seconds and then it changes to no signal. It also seems that after the GBS8220 has been switched on I can only control its menu for minute maybe and then it just displays the No signal and I can't make the menu come up unless I switch it off and on again.
I'm now wondering if I have a faulty GBS8220. What do you think?
What could I test on that itself to see if it is working correctly?
Just had another thought. I tested the voltage coming from the power supply and it is supplying 5.22V according the multimeter. A youtube video showing one being used with a Jamma board commented that they had loads of problems if the voltage was too high, so I'm thinking this might be one possible problem. I'm therefore going to connect up the supplied power cable to the Amiga RGB port and power it that way to see what that does.
Yes, I don't recommend powering from the port (as mentioned earlier in this thread) the GBS needs a tad more to run. I don't think its the whole 2A but it is recommended that one use a 2A PSU as you are already Harrison. But is it 5.22V when connected to the GBS and powered? Thats the most important measurement. It may well measure 5.22V without load, but if its still measuring 5.22V whilst powering the GBS then yes, this could be too high. I heared this problem too.
You should Definately be able to see the picture of the inbuilt menu regardless of whats plugged into it.
If your PSU is ok (no more than 5.11V when powering the GBS) One other thing to try if you haven't already. Plug in the GBS without the Amiga connected, just power. Then try and auto sync your monitor to the GBS and see if that brings it to life. You should see some blue Chinese characters for a moment, and then the GBS outputs a "No Signal" message in white. If your monitor syncs to it ok, then you should then be able to access the inbuilt menu to then setup the GBS output. Its a bit confusing as you are dealing with an onboard driver for your monitor with a menu and then the GBS menu!
Try and sync your other monitors too and see what happens.
Otherwise it does seem like you have a duffer.
You should Definately be able to see the picture of the inbuilt menu regardless of whats plugged into it.
If your PSU is ok (no more than 5.11V when powering the GBS) One other thing to try if you haven't already. Plug in the GBS without the Amiga connected, just power. Then try and auto sync your monitor to the GBS and see if that brings it to life. You should see some blue Chinese characters for a moment, and then the GBS outputs a "No Signal" message in white. If your monitor syncs to it ok, then you should then be able to access the inbuilt menu to then setup the GBS output. Its a bit confusing as you are dealing with an onboard driver for your monitor with a menu and then the GBS menu!
Try and sync your other monitors too and see what happens.
Otherwise it does seem like you have a duffer.
It is alive! I've powered it from the Amiga now and it is working perfectly. Initially the image was a thin strip in the middle of the monitor and very dark, but a quick fiddle with the geometry settings and it revealed the sides, and as it did the colour and brightness sorted themselves out.
So yes, powering it from the Amiga port seems to work perfectly. And I'm very impressed with the image quality so far. No distortion, no noise or snow others have reported, when I think, along with reports of a pink screen, are all to do with over voltage to the board.
When powered from the standalone PSU the board would power up OK. I never had a problem with that and could see the chinese characters and then access the menu. But the board would then freeze a couple of minutes later and need to be restarted, which I'm now thinking was due to too much voltage.
Anyway... it is all working now. The cable I current have made up looks a complete mess as I was experimenting to get it working... I connected the boards power cable to standard molex connector to make it easy to connect up, and joined a molex cable to the Amiga port 5V out so that can easily be connected and disconnected.
I am now wondering if the VGA port will work as it was acting exactly the same way and could have also been due to the over voltage. For that it would be better to use external power though so I still need to source a good 5V 2A PSU for this board. Anyone recommend one?
So yes, powering it from the Amiga port seems to work perfectly. And I'm very impressed with the image quality so far. No distortion, no noise or snow others have reported, when I think, along with reports of a pink screen, are all to do with over voltage to the board.
When powered from the standalone PSU the board would power up OK. I never had a problem with that and could see the chinese characters and then access the menu. But the board would then freeze a couple of minutes later and need to be restarted, which I'm now thinking was due to too much voltage.
Anyway... it is all working now.
The cable I current have made up looks a complete mess as I was experimenting to get it working... I connected the boards power cable to standard molex connector to make it easy to connect up, and joined a molex cable to the Amiga port 5V out so that can easily be connected and disconnected. I am now wondering if the VGA port will work as it was acting exactly the same way and could have also been due to the over voltage. For that it would be better to use external power though so I still need to source a good 5V 2A PSU for this board. Anyone recommend one?
Have you seen this Enclosure for the GBS8220?
http://wp1114205.wp150.webpack.hosteurope.de/xtcmodified/product_info.php?products_id=14
Quite expensive, but it does look nice and would be great for events.
http://wp1114205.wp150.webpack.hosteurope.de/xtcmodified/product_info.php?products_id=14
Quite expensive, but it does look nice and would be great for events.
WOOP! AWESOME Harrison! 
Well you proved its the PSU by wiring to the port +5V, and good that you will soon get a seperate PSU. Its okish to power from the RGB port but its pushing it a bit and if there is a problem it could damage your Amiga. I do think 2A is a bit overkill, more 500mA so maybe a 1A supply would be safe enough. I think i'll do some measurements off the GBS whilst its running and post here what current it actually draws in real life. ATM it will be hard as i've stripped most of the connectors off ready for my Box conversion, but once its all done i'll let you all know.
That case is indeed nice and flashy, deffo good for shows and if you only plan to use the GBS with no SLG or SS then it would be good, otherwise a bit clunky with all them small perspex cases lying around. For me I want all my chit in a box with one PSU
But anyway, enjoy m8! glad you got it working 
Well you proved its the PSU by wiring to the port +5V, and good that you will soon get a seperate PSU. Its okish to power from the RGB port but its pushing it a bit and if there is a problem it could damage your Amiga. I do think 2A is a bit overkill, more 500mA so maybe a 1A supply would be safe enough. I think i'll do some measurements off the GBS whilst its running and post here what current it actually draws in real life. ATM it will be hard as i've stripped most of the connectors off ready for my Box conversion, but once its all done i'll let you all know.That case is indeed nice and flashy, deffo good for shows and if you only plan to use the GBS with no SLG or SS then it would be good, otherwise a bit clunky with all them small perspex cases lying around. For me I want all my chit in a box with one PSU
But anyway, enjoy m8! glad you got it working
I just had an interesting idea. I've wanted a solution similar to this for my A4000 for some time, but don't really need a dedicated graphics card in the system for what I use it for. So I'm thinking that if I replaced the original A4000 PSU with a much smaller ATX one, this would leave a lot of room above the PSU... where a GBS8220 could be fitted, with it powered from the new PSU, so it would power up with the A4000.
And anyone with more soldering skills than me, I could imagine they could solder the supplied wiring harness internally within the A4000 so you wouldn't even need to plug anything into the exterior RGB port.
Good idea?
And why not consider the same for other big box Amigas too. Also is there any reason this might not also fit inside and A500 or A1200? There probably is just enough room.
Much cheaper than any dedicated Amiga FF/SD, although obviously not as advanced as a proper one like the Indivision.
And anyone with more soldering skills than me, I could imagine they could solder the supplied wiring harness internally within the A4000 so you wouldn't even need to plug anything into the exterior RGB port.
Good idea?
And why not consider the same for other big box Amigas too. Also is there any reason this might not also fit inside and A500 or A1200? There probably is just enough room.
Much cheaper than any dedicated Amiga FF/SD, although obviously not as advanced as a proper one like the Indivision.I'm considering buying another GBS, then I will have one dedicated to Amiga use, and with the case... and the other will be connected with the Sync Strike, and those could go into a dedicated box together for console connecting. I could even look into integrating a scart switcher box into the same case so everything is an all in one solution.
hehhe wots with the tripple posting harrison LOL whos all excited
hopefully I`ll be trying mine today or tommow, got the A1500 out and on my desk now I got room after striping the PC down to replace the PSU
that is indeed a nice enclosure
hopefully I`ll be trying mine today or tommow, got the A1500 out and on my desk now I got room after striping the PC down to replace the PSU
that is indeed a nice enclosure
