Old monitor = no boot on G4? — #1

Post #1 by Bunsen

Source Forum	68kMLA
Category	Troubleshooting
Post Date	Tue, 14 Sep 2010 - 18:47
Original URL	https://68kmla.org/bb/threads/old-monitor-no-boot-on-g4.21297/

Post

Got a little video related mystery for you all:

I've been testing out my miniature CRT monitors on my QS G4 (OS X 10.4.11, Geforce 4MX AGP video card, VGA + ADC).

Plugging in the "Esteem" brand colour 10" VGA (1991, model cd-1035) works fine (although it's a bit .. meh, as a monitor.)

However, plugging in the greyscale 9" CRT (1994, TUV Product Service GS [unreadable], part no. MA-0933) results in a chime, but no boot, even though there's an ADC monitor present on the other port. I've tested this with two identical monitors with the same result. The monitors (or at least one from the same batch) have previously been shown to work OK on some other system (probably a P4-era or earlier PC/Windows - it was a while ago).

I headed over to pinouts.ru and prepared a table comparing the pins present on each monitor:

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Monitor cable end.

Code:

Pin  Name       Grey  Colour  Description

1    RED                X     Red Video (75 ohm, 0.7 V p-p)
2    GREEN        X     X     Green Video (75 ohm, 0.7 V p-p)
3    BLUE               X     Blue Video (75 ohm, 0.7 V p-p)
4    ID2                      Monitor ID Bit 2
5    GND          X     X     Ground

6    RGND         X     X     Red Ground
7    GGND         X     X     Green Ground
8    BGND               X     Blue Ground
9    KEY                      Key (No pin)
10   SGND         X     X     Sync Ground

11   ID0                X     Monitor ID Bit 0
12   ID1/SDA      X           Monitor ID Bit 1
13   HSYNC/CSYNC  X     X     Horizontal Sync (or Composite Sync)
14   VSYNC        X     X     Vertical Sync
15   ID3/SCL                  Monitor ID Bit 3

Any thoughts, people?