VGA monitor adapter killed my sprites

[SpheriX]

I've built this VGA adapter cable (turning the wires in mirror image from what should be the correct wireing), and since then I've got the following problem: =)

The sprites are garbled (games); the cursor pointer is jumping and erratic. I have not noticed anything else though. I've ran several sys info programs, but everything shows up normal. Screens are displayed correctly.

a) Is it the AGA Lisa that is fried
b) maybe video clocking circuit is dead?

 :-?

[Matt_H]

The Commodore VGA adaptors were more than just cabling. There was also a chip inside. Run the machine with a normal RGB cable to a 1084 (or similar) or a TV through the composite port. Is everything okay? Then your VGA cable is probably faulty.

[SpheriX]

Yes,but I have the problem described when connected via composite video-out too. I've noticed the C811 (1000uF) has leaked too.Mouse-pointer cursor sprite is flaky when moving it across the screen, vector GFX (Trex Warrior) is working, but the sprites are not always shown properly.
Could this be the mouse-buffer logic or what else?

[Framiga]

without a TTL inverter on the H-V Sync lines, Amiga "thinks" that a genlock is connected, and hence . . .strange things happens ;-)

ftp://de.aminet.net/pub/aminet/hard/hack/ami2vga.lha

[SpheriX]

I've disconnected the faulty VGA cable, but the problem persists even without it. Some kind of voodoo I guess, but now the mouse cursor dissapears from time to time, otherwise moves normally ?! I wish if I could find more on this on the Net (tried several a1200 troubleshooters, but none was in-detail enough).

[bloodline]

SpheriX wrote:
I've disconnected the faulty VGA cable, but the problem persists even without it. Some kind of voodoo I guess, but now the mouse cursor dissapears from time to time, otherwise moves normally ?! I wish if I could find more on this on the Net (tried several a1200 troubleshooters, but none was in-detail enough).

Well A1200's are old now, expect them to start failing.

[SamuraiCrow]

It could be the Lisa chip.

I doubt it would be the video-clocking circuit since the main display DMA works properly...

[Matt_H]

Yes,but I have the problem described when connected via composite video-out too.

Oh. Yeah, that's probably a problem on the motherboard. Clean up and replace the capacitor if you can. If not, time to ring up a repair shop.

From what I remember reading, Amiga.fr (which no longer resides at that address, but is still around; check links page) does Amiga repairs, as does Mr. Hardware in New York.