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Strange S-20



Strange S-20 | 3 November, 1999

We have Siemens S-20 machine whose other gantry occasionally missmounts all its components in Y-direction(approx. 1/2 mm ). Most of the missmounts happens when there is a lot of 0603 or 0805s (B-side glue boards). Gantry picks up the components OK but missmounts them !!! The Strange thing about this is that when we turned our line 180dec. , also the fault turned from gantry 2 to gantry 1 ... Machines are well balanced (Siemens service has checked them). anyone having a same kind of problem ??? siemens service guys just spread their arms wide open when asking about this ...

Thanks in advance ...

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Re: Strange S-20 | 3 November, 1999

Hi Wes, it may not be the same but I had a problem with one Phillips machine which started unpredictible mismounting all components about 1mm. When it occured you couldn�t get it do it right again unless you turned it down and restarted it. The service people also stood there and had no idea cause that wasn�t happening when they were at the side runnig their testprograms. First idea that it had to do with the board and the program turned out wrong. In our case the placement offset determined when measuring the incoming PCB was lost in the RAM due to connectorproblems of the RAM-bank. Another thing we encountered was that sometimes especially with HAL-PCBs the position of the PCB wasn�t determined correct due to misreading the fiducials.

This might be worth looking at Wolfgang

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PL Sasso


Re: Strange S-20 | 3 November, 1999

Hi Wes,

I was very interested in your S20 problem since I am the Customer Support Center Mgr. for Siemens EAE here in the US. This sounds like a solvable problem. Most likely, due to the random nature, it involves how the vision is locating the pcb upon entry into the machine. Please give me a call @ 1888SMTHELP and I can try to provide some assistance.

Paul Sasso 7707973295

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Stefan Witte


Re: Strange S-20 | 5 November, 1999

I would blame the line computer software. You may have a job in there which wasn't properly closed. Although I haven't experienced problems like yours, I've heard about other weird placements due to line computer's "overload".

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Re: Strange S-20 | 5 November, 1999

Explain computer "overload". Specific examples would be helpful.

Regards Nick

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