On Sat, Nov 6, 2010 at 2:37 AM, Ákos Maróy <a...@maroy.hu> wrote: > Andrey, > > I just had time to disconnect the board from the CCD and re-connect it. > my results are good and bad at the same time. I'm getting a good image > in general - but I can also reproduce the broken image I sent. The way > to reproduce is: if I screw in the 'top-left' screw of the board into > the case 'totally', then the image is broken. if I let this screw to be > a bit loose, it's OK. > > as all the other screws are already in, this loosening / tightening does > not change the physical orientation of the board in relation to the CCD. > > so this really seems to be extremely sensitive. > > Akos >
Akos, Yes this is consistent with what would happen with the board if you really twist it (trying to solve the problem that turned out to have nothing to do with the camera itself) - some of the pads on the chips got pulled off from the board and now the contact is only occasional - when they touch each other. If it is just the ball(s), not the traces - we might be able to repair the board by running it through reflow oven. Meanwhile (as you will be away from your place and can not receive the replacement board during that time) if the camera sometimes works, you may try to temporary repair it. From the image the problem is ion the ball contacts of one of the two chips - on the image http://wiki.elphel.com/images/3/38/10353top.jpeg (it is previous revision, but similar) you can see FPGA on the right side by the connector (large, square) and the video memory - rectangle right above it. Most likely the problem is with the memory - when you twisted the board it got more stress as it is near the board edge. You may try to put a piece of plastic on top of the memory chip and then wrap the board with a thread, so that plastic piece would push the chip to the board. It may still be the FPGA chip, because the connection in data lines between the two is broken, and it is only my guess that it is under the memory. Andrey
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