Page 1 of 2
Magenta Divine
Posted: 08 Apr 2021 10:15
by russellnash
Hi,
I get the following screen from a 1040STF Revision B:
nicecolour.JPEG
Everything seems to work fine, just no colours other than pink and black. It is a great colour, but others would be nice. Anybody know or guess what causes it? I don't have a diagnostic cartridge yet.
Re: Magenta Divine
Posted: 08 Apr 2021 10:24
by exxos
Bad RGB cable / socket ?
Re: Magenta Divine
Posted: 08 Apr 2021 10:24
by rubber_jonnie
I don't think a diag cart will help much with that.
What sort of cable are you using? A lot of STFs are missing the composite signal so that may be the problem, I'd suggest starting with the socket, make sure there are no dry/cracked solder joints.
Re: Magenta Divine
Posted: 08 Apr 2021 10:29
by russellnash
Hi exxos and Johnnie,
sorry I am connected to an LED Monitor via VGA cable using an adapter from the Exxos shop. The same cable, adapter and monitor don't have that problem on any other ST. So maybe the socket connections?
Re: Magenta Divine
Posted: 08 Apr 2021 10:31
by rubber_jonnie
russellnash wrote: 08 Apr 2021 10:29
Hi exxos and Johnnie,
sorry I am connected to an LED Monitor via VGA cable using an adapter from the Exxos shop. The same cable, adapter and monitor don't have that problem on any other ST. So maybe the socket connections?
I'd start with the socket, yes.
Re: Magenta Divine
Posted: 08 Apr 2021 10:33
by russellnash
Thanks, I will give it a try.
Re: Magenta Divine
Posted: 08 Apr 2021 13:31
by stephen_usher
I've seen similar with a corroded Shifter pin. A reseat of the chip fixed it.
Re: Magenta Divine
Posted: 08 Apr 2021 15:09
by russellnash
The very first thing I did was change the Shifter from another machine. So, no signal arrives at pin 6, so no Green. Been trying to find a pin layout of the Shifter, the schematics I have found are either illegible or I don't understand them. Is pin 6 on the socket pin 6 on the chip?
Re: Magenta Divine
Posted: 08 Apr 2021 15:10
by exxos
russellnash wrote: 08 Apr 2021 15:09
The very first thing I did was change the Shifter from another machine. So, no signal arrives at pin 6, so no Green. Been trying to find a pin layout of the Shifter, the schematics I have found are either illegible or I don't understand them. Is pin 6 on the socket pin 6 on the chip?
https://www.exxosforum.co.uk/forum/viewt ... f=31&t=149
Re: Magenta Divine
Posted: 08 Apr 2021 15:34
by russellnash
The diagram is in German too, great. Green 24-26 are noticeable in so far as they show 5V instead of 3V on the Blue and Red.