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???
03/02/04 17:48
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#65828 - RE: vga signals isolation problem ( I think)
Responding to: ???'s previous message
Dear Mr Rudra
Here is more description of the problem:
The machines belong to a bowling club, they have 6 MCUs installed, each MCU controls 2 lanes and they have 12 lanes altogether. each lane has an overhead monitor 29" and lower console monitor 14" vga displays, so we have 24 displays altogether.
Sometimes a display turns off while we are playing ( once a week or every 2 weeks) unfortunately the displays break at random and no specific location.
Some other times when we switch the power on first thing in the morning, some monitors don't turn on while they have been perfect in the previous night. In most cases the VGA chip gets exploded with big crack in the middle like an earthquake has hit it. some times the pins of the vga chip get melted as if a lightning had struck it. The darn thing works beautifully for a week and then lanes start going down.
One day all MCUs went stuck with a strange error message, after contacting the manufacturers in korea they said they never heard of this problem before, further investigation showed that a small eeprom had corrupted its program, I had one spare MCU working so I coppied the program to the rest of them and they all worked again.
So it looks like some EM wave struck the bowling club erasing the small eeprom inside the cased MCUs.
things get strange for I had no problems for 1 month contenuous and now we are having failure waves again.
I will be travelling to uk for 3 weeks next week so I guess by the time I come back 90% of the lanes would be down due to strange phenomenon striking the place.
Unfortunately the MCU costs 3500$ and reparing it in the company costd 350$ while for me repairing it just costs the parts. I'm sick of repairing the same problem over and over again so there must be something severly wrong with the design for they didn't have any protection circuits on the output of the video driver chip to keep milking the customers I guess.
there is no service manual or any circuit diagram for the MCU, so I already started building alternative system using a normal PC and web camera with some image processing program using C++ language.

Why does the C versus assembly dilema keeps popping up all over the place?
Please keep programming in assembly till your hearts content, as long as you get your projects done successfully.

So if you have any useful comments to help me sort this problem please contribute.
Thank you for your time.
mahmood

List of 38 messages in thread
TopicAuthorDate
vga signals isolation problem ( I think)            01/01/70 00:00      
   RE: vga signals isolation problem ( I th            01/01/70 00:00      
      RE: vga signals isolation problem ( I th            01/01/70 00:00      
         RE: vga signals isolation problem ( I th            01/01/70 00:00      
            RE: vga signals isolation problem ( I th            01/01/70 00:00      
            RE: vga signals isolation problem ( I th            01/01/70 00:00      
   RE: vga signals isolation problem ( I th            01/01/70 00:00      
      RE: vga signals isolation problem ( I th            01/01/70 00:00      
         Capacitance - not cable length!            01/01/70 00:00      
            RE: Capacitance - not cable length!            01/01/70 00:00      
               RE: Capacitance - not cable length!            01/01/70 00:00      
               VGA Video            01/01/70 00:00      
      RE: vga signals isolation problem ( I th            01/01/70 00:00      
         RE: vga signals isolation problem ( I th            01/01/70 00:00      
            RE: vga signals isolation problem ( I th            01/01/70 00:00      
   RE: vga signals isolation problem ( I think)            01/01/70 00:00      
   Cable capacitance is not an issue!            01/01/70 00:00      
      RE: Cable capacitance is not an issue!            01/01/70 00:00      
         RE: Cable capacitance is not an issue!            01/01/70 00:00      
            RE: Cable capacitance is not an issue!            01/01/70 00:00      
               RE: Cable capacitance is not an issue!            01/01/70 00:00      
                  RE: Cable capacitance is not an issue!            01/01/70 00:00      
                     RE: Cable capacitance is not an issue!            01/01/70 00:00      
                        RE: Cable capacitance is not an issue!            01/01/70 00:00      
   RE: vga signals isolation problem ( I think)            01/01/70 00:00      
      RE: vga signals isolation problem ( I think)            01/01/70 00:00      
         RE: vga signals isolation problem ( I th            01/01/70 00:00      
         That is not caused by a normal ESD!            01/01/70 00:00      
            RE: That is not caused by a normal ESD!            01/01/70 00:00      
            RE: That is not caused by a normal ESD!            01/01/70 00:00      
               RE: That is not caused by a normal ESD!            01/01/70 00:00      
               RE: That is not caused by a normal ESD!            01/01/70 00:00      
   RE: vga signals isolation problem ( I th            01/01/70 00:00      
      Bowling alleys            01/01/70 00:00      
      RE: vga signals isolation problem ( I th            01/01/70 00:00      
         RE: vga signals isolation problem ( I th            01/01/70 00:00      
         Go bowling, Michael            01/01/70 00:00      
            RE: Go bowling, Michael            01/01/70 00:00      

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