Graphics corruption

[rvo_nl]

thanks both, for your help. there is only one way to test this, with another ppc and/or a1200 mainboard. I will try to find someone in my neighbourhood to help me out.

This night I tried some old 32MB Simm and also swapped Bvision, video cable and connector PCB around, all without result.

I had a very close look at the ppc board, it really looks fine, also under the heatsink I dont see any damage.

[rvo_nl]

tried that, didnt help.
 
HOWEVER..
 
take a look at this wonderful, glitch-free screen:
 

 
this is with another a1200 mainboard. When I put my own board in, and go to CGXmode, I get instant artifacts. So, case closed. I need a new motherboard!
 
no wait, I should have tested  a bit more. Now I have the exact same problem again, with a different motherboard. It happens less, but for example when I move the window in the picture above, the lines come back again. So, must be the PPC then. I guess that means its the end, coz Im sure as hell not replacing that one.

[rvo_nl]

so, every screen after the first 1024x768/15bit screen has artifacts. its not related to the bvision. its not related to the memory on the ppc. its not related to the motherboard. its not related to software. its not related to any other on-board component. how can it be anything else than the ppc board itself? and if thats the case, which specific component is probably at fault here? Stachu? Delshay? ..is this something that is cured with a new 300mhz 603?

[rvo_nl]

thanks.. I guess

Ofcourse I have the latest flash.

[rvo_nl]

Yes, I did actually try different HD cables
 
I indeed did not try with a different PSU or Elbox tower, so who knows.. but do you really think that is going to cause artifacts on every second RTG screen opened? :/
 
I did try in my current home and my previous one, with the same results. Again I cannot believe such a thing will cause such a specific glitch in my display.
 
I guess I can do one more test, in a different tower with a different PSU..
 
One thing that keeps bothering me, could it be that - something - in my tower is damaging all my bvisions? For example that little wired PCB you plug in that Bvision 'hole', which comes with the Elbox tower and is used for the LED's? Did it short circuit the video memory of all my bvisions? :| There is 12v on it, after all..
 
I ask this because, I remember having had similar graphical artifacts way back that I solved by getting a new bvision. At that time I got 3 (one broken) of which 2 I am constantly using for testing. (with and without that little circuit board I mentioned)
 
Can someone tell me where the video memory is located on the Bvision? Is it near the hole in the middle?
 
edit: OMG, reading back this actually seems plausible..
 
This is the LED PCB Im talking about: http://eu-shop.elbox.com/cgibin/shop?info=562ELED&sid=7c715f4b
 
This is the Bvision: http://www.amiga-hardware.com/download_photos/bvision_front_big.jpg
 
Note that this is the side where the PCB touches the Bvision. Also note that OFCOURSE I did protect the bvision against shorting by wrapping the PCB in ducttape, but you know, over time I guess the pins of the PCB will go right through it..
 
btw delshay, I see now that you already pointed out a possible short circuit resulting in graphics output looking like this.

[rvo_nl]

Well, its hard to find experts these days..
 
Also I think you misunderstood. Its the floppy power connector in which I have to put this little Elbox circuit boards that powers my LED's, it also provides extra power to the motherboard. This circuit boards is a bit bigger than the hole inside the bvision, so the sides of it press against the bvision circuit board itself. Since there is power being fed over this PCB, perhaps this has damaged the Bvision components near the hole?
 
Here, see this drawing I made:
 


Also I must say the version of this Elbox LED thingie that I have looks a bit different.

[rvo_nl]

thanks for clearing that up. although I cant be sure one of the other components is affecting the SGRAM. What about the chips on the backside of the bvision, can they be damaged by touching the motherboard? Not too uncommon in A1200T's I guess..

[rvo_nl]

Hello, it's been a while. But for those that are interested, after much fiddling around I bought a new bvision and the problems are gone. I've added a 80mm fan to my machine that blows cold air on the permedia chip all the time, since many suspected heating issues. And to be honest, Ive ruled everything else out. Im probably a very unlucky person having burned 3 or 4 bvisions in a short time.

Thanks for all your help!

[rvo_nl]

I did in fact, there too the artifacts showed up. Perhaps I didnt make myself clear. My first ever bvision started showing the artifacts. I then bought 2 new ones, that initially worked. only over time, say 6 months, they too started misbehaving. another bvision never worked from the start. Yes, I now have 5.

[rvo_nl]

delshay, you really know your stuff, no doubt. but right now Im just happy with the standard bvision, I will not overclock indeed, one of the bvisions is missing components, you have a good eye for details

actually I think the bvision is an excellent card. sure, its not very fast anymore but its more or less the only way to get rtg to your a1200 without buying a pc card like voodoo. for me, that counts. for many others, it doesnt.

[rvo_nl]

The PCB you insert maybe work itself a little loose and comes into contact with Bvision maybe when you move the unit or due to vibration.

hang on, what do you mean with PCB? you mean the bvision or the motherboard here?
 
stachu looked at my problem (from a distance) and concluded it must have been overheating, thats why I added a 80mm fan. that thing is huge. if the cause was really heat, then I think this has solved it. but still im interested in hearing about other precautions, thats why I asked my previous question. please let me know.

[rvo_nl]

ah yes, that one. Indeed I do. Ive already made sure its insulated even more. theres for sure no solder points sticking out and touching the bvision now. thanks for sharing your concerns