Crystal Castles Voltage Drop ...

kentmurphy

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Ok, I am getting a large voltage drop from the ARII to the gameboard. Below are my readings.

ARII - Back of J7 = +5.31
EMI Shield - Back of Edge Connector = 5.17
EMI Shield - Traces = +5.14
EMI Shield - Back of Gameboard Edge Connector = +5.06
Gameboard - Traces = +5.00

Yes, it still has the EMI shield. I am guessing the first step is to replace the edge connectors which connect to the EMI shield. I have also read that the EMI shield is not needed. Should this also be removed? Almost 2/10 of a volt is lost in the EMI shield alone. What is the purpose of this board (besides EMI protection) and why have people suggested removing it?

Kent
 
Kent definently remove the shield. What happens is eventually the edge connector on your PCB will become dirty and loose ground and will burn components (typically one resistor I forget location of) on your ARII board. In fact I have one that literally has a dime sized whole it and the previous owner used a larger resistor to jump the trace with heh.
 
Kent definently remove the shield. What happens is eventually the edge connector on your PCB will become dirty and loose ground and will burn components (typically one resistor I forget location of) on your ARII board. In fact I have one that literally has a dime sized whole it and the previous owner used a larger resistor to jump the trace with heh.

R29 is what Deadly is searching for.
 
Kent definently remove the shield. What happens is eventually the edge connector on your PCB will become dirty and loose ground and will burn components (typically one resistor I forget location of) on your ARII board. In fact I have one that literally has a dime sized whole it and the previous owner used a larger resistor to jump the trace with heh.

Are you referring to the edge connectors which connect to the EMI shield or the connectors on the shield which connect to the gameboard?

Kent
 
Would anybody with a Crystal Castles be willing to take the same measurements I did? I would like to know the size of your voltage drop.
 
  1. Remove the shield.
  2. Connect the wiring harness directly to the boardset
  3. Take the measurements again.
Lastly, if it aint broke don't fix it.:D
 
Those drops don't sound outlandish. I'd just clean all the edge connectors. I wouldn't even remove the EMI filter board.
 
Thanks bit_slicer. I am also beginning to believe this voltage drop isn't problem. Before I explain my logic I have attached a picture indicating the location of where I took each measurement.

A = +5.31
B = +5.17
C = +5.14
D = +5.06
E = +5.0

While the total voltage drop of .31 looks bad, it really isn't when you consider the number of connections the electrons must flow through and the voltage drop issue I encountered on my Asteroids Deluxe. Even after replacing the edge and molex connectors at both the gameboard and AR PCBs on my AD, I was still losing .15 of a volt between the AR board and the edge connector. If you assume an old harness and an EMI shield PCB can each cause an approximate voltage drop of .15, the .31 drop would seem to be normal. I know this logic may be flawed, but even if it is I will fall back on Dokert's words of wisdom; if it ain't broke, don't fix it. In summary, I don't plan on removing the EMI shield PCB or changing the edge connectors. I will clean the edge pads on both the EMI shield PCB and the gameboard with an eraser and deoxit. Once complete, I will call it a day. :)

Kent
 

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Wow, look what a cleaning did!

Before ...

A = +5.31
B = +5.17
C = +5.14
D = +5.06
E = +5.0

After ...

A = +5.19
B = +5.10
C = +5.08
D = +5.05
E = +5.0

In my first cleaning I did not clean the pads on the gameboard. I only cleaned the pads on the EMI shield PCB. This time I did cleaned both pads and what a difference it made. Wow!

Kent
 
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