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General Category => Technical Support - General => Topic started by: darias on 12:08, 17 April 19

Title: Need a help with GBS8200
Post by: darias on 12:08, 17 April 19
Greetings.I own a CPC 6128 with green monitor.Few weeks ago I buy a zaxxon floppy 3'' (internal) fit it inside my 3'' disc drive bay.The system I buy it from a wherehouse in very bad condition ,but I fix it and it run perfectly.Tho it trouble me the GBS 8200 I got. Since I have 5 CRT vga monitors ( 3  LG 700s ,1 Samsung sycnmaster 765 1 MONXX) and one Dell LCD monitor so decide to get a cheap 8200 corverter and use it an CRT for my CPC.The problem is, the image quality is good, but the colors are not. I have solder as the images on an other review the 5 pin DIN connector but after a week i try to find solution, I discover the green color (from RGB) like doesn't show at all.I try all monitors (except the Dell TFT doesn't get any signal at all from the GBS) . The others work but with wrong colors.
The cables are soldered correctly.
If someone had same issue in the past, and know some solution, please show me, because is pitty having nice CRT VGA monitors and don't enjoy them with my Amstrad.Here is with photos what colors I get from my monitors
As you all see, is like green signal (from red green blue combinations) is missing. But in my green monitor the hues are correct.Any help is welcome  :(
Title: Re: Need a help with GBS8200
Post by: TotO on 13:01, 17 April 19
Funny to know that your green monitor had never displayed this colour!  :-\
Title: Re: Need a help with GBS8200
Post by: darias on 14:19, 17 April 19
 :)
Title: Re: Need a help with GBS8200
Post by: darias on 12:39, 18 April 19
Wow ...so no one can give a clue what possibly going on?
Title: Re: Need a help with GBS8200
Post by: Fessor on 12:48, 18 April 19
By green Monitor you mean the GT64/65 with its own cable?
Try INK 0,18 or BORDER 18. If nothing happens on your green screen, the connector is bad. If something happens on the geen screen, your cable for your other Monitors is bad.
(Because you are changing the color to an intense green)
Title: Re: Need a help with GBS8200
Post by: robcfg on 15:03, 18 April 19
Definitely the green component isn't getting through.


Maybe you wired that wrong or there is another problem.
Title: Re: Need a help with GBS8200
Post by: darias on 00:28, 19 April 19
Quote from: Fessor on 12:48, 18 April 19
By green Monitor you mean the GT64/65 with its own cable?
Try INK 0,18 or BORDER 18. If nothing happens on your green screen, the connector is bad. If something happens on the geen screen, your cable for your other Monitors is bad.
(Because you are changing the color to an intense green)
The color turn to intense green as you said. So there is no problem with the CPC socket. But the wires on the other 5 pin din connector I have are soldered correctly. So maybe is the connector  not fit well? I got this few weeks ago https://www.ebay.co.uk/itm/6-PIN-DIN-MALE-PLUG-CONNECTOR-FOR-AUDIO-EQUIPMENT-VINTAGE-COMPUTER-SYSTEMS/390970151360?ssPageName=STRK%3AMEBIDX%3AIT&_trksid=p2060353.m2749.l2649.I (https://www.ebay.co.uk/itm/6-PIN-DIN-MALE-PLUG-CONNECTOR-FOR-AUDIO-EQUIPMENT-VINTAGE-COMPUTER-SYSTEMS/390970151360?ssPageName=STRK%3AMEBIDX%3AIT&_trksid=p2060353.m2749.l2649.I) got 2 actually ..but both faulty?
Do someone have any other 5 pin din suggestion? Maybe if I try connect directly without the 5 din see if is ok ..if yes, then the connectors are faulty.
Title: Re: Need a help with GBS8200
Post by: Fessor on 06:21, 19 April 19
Its unlikely that two fresh connectors are broken at the same pin. Do you have a multimeter?
Whats on the other end of your Cable? I would also check the cable for itself if the line is broken.
Title: Re: Need a help with GBS8200
Post by: robcfg on 09:43, 19 April 19
Can you try to swap the green and red cables on the GBS8200 and take a picture?


If it only shows blue or red and blue, the green wire is not soldered to the right place, or it is broken.
Title: Re: Need a help with GBS8200
Post by: Audronic on 10:01, 19 April 19
There are 3 Pots on the GBS R/G/B Maybe they are out of adjustment ? ?


Take a photo of the pots before altering adjustment ?



Ray
Title: Re: Need a help with GBS8200
Post by: darias on 19:24, 19 April 19
Quote from: robcfg on 09:43, 19 April 19
Can you try to swap the green and red cables on the GBS8200 and take a picture?


If it only shows blue or red and blue, the green wire is not soldered to the right place, or it is broken.
I swap red with green ..and now picture looks like this .
Looks like  isn't the cable . Otherwise wouldn't show the dragon red.I said about the 6 pin din connectors ..because the original from the monitor,  inside the connector is 'thicker' ..and the 2 i buy from cool novelities are thinner ....that I believe maybe not good contract with the cpc socket ...?
Title: Re: Need a help with GBS8200
Post by: darias on 19:45, 19 April 19
Quote from: Audronic on 10:01, 19 April 19
There are 3 Pots on the GBS R/G/B Maybe they are out of adjustment ? ?


Take a photo of the pots before altering adjustment ?



Ray
I test the pots and tried to adjust the colors from the second day as you said. But every combination didn't gave me the proper picture either. Now for example , the three of them i set them to default 'far left'
Title: Re: Need a help with GBS8200
Post by: Audronic on 23:29, 19 April 19
@darias (http://www.cpcwiki.eu/forum/index.php?action=profile;u=3084)


Ok I just checked my GBS and the default for the pots appears to be all anticlockwise.


It looks like the GBS Is unwell.


Ray
Title: Re: Need a help with GBS8200
Post by: darias on 13:01, 21 April 19
Quote from: Audronic on 23:29, 19 April 19
@darias (http://www.cpcwiki.eu/forum/index.php?action=profile;u=3084)


Ok I just checked my GBS and the default for the pots appears to be all anticlockwise.


It looks like the GBS Is unwell.


Ray
My pots are the same 'far anticlockwise'. Yesetrday I tried my TFT Dell monitor.But had the same issues ..not only that , but I had artifacts in the screen and ghosting too (something didn't had with CRT monitors.I even apply a spare PSU I have from an old PC, I power up it with it, (since I was afraid maybe because there no ground on the board but no even on my CPC too , because the cable is only 2, not 3 to have ground also).
Title: Re: Need a help with GBS8200
Post by: Bryce on 19:17, 21 April 19
The artifacts are due to the manufacturer changing the RAM timing. There's a hack to undo this, but it involves adding a small circuit with a µP to inject commands after it boots. It's a bit complicated for users who can't build their own hardware.

Bryce.
Title: Re: Need a help with GBS8200
Post by: darias on 22:33, 22 April 19
So possibly my gbs is faulty ....I have no other old computer to taste it 'except a commodore64C but no cable for test ....Looks like have to take the scart cable and test it in my old CRT TV
Title: Re: Need a help with GBS8200
Post by: darias on 12:36, 08 May 19
Hi againOk I buy a scart cable and connected with my old CRT TV..the colors look correct with the SCART cable, so means , my GBS is faulty from the start :-X Thanks for the response in my topic
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