Edwards Active Gauge Controller Teardown

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AngeloGomes
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Edwards Active Gauge Controller Teardown

Post by AngeloGomes »

The guy :

Image
The image/picture above is from someone else, mine is not in good shape as you will see below.


the symptom: No gauge is detected anymore and display shows ???ID
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AngeloGomes
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Re: Edwards Active Gauge Controller Teardown

Post by AngeloGomes »

Well, this is a long story already posted here, and the original topic was lost with the forum last week.

Below is how my AGC looks right now.

Sometime ago, the membrane keyboard died, all keys. I´ve sent to Edwards representative who said the cheapest option I have was to forget the membrane keys and install mechanical switches/buttons, that I accepted.

So, here is mine AGC (the front panel), of course, now with some key caps missing after 5-7 years.

Image
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AngeloGomes
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Re: Edwards Active Gauge Controller Teardown

Post by AngeloGomes »

The AGC has tree boards:

1) Power board
2) Display board
3) Mainboard



The display board is shown below:

Image


The conector pin (PL9) is where the keyboard flat cable is attached.
After some time playing around with these pins I found:

Pin 1 = Up Key
Pin 2 = Down Key
Pin 3 = Cycle Key
Pin 4 = Enter Key
Pin 5 = Escape Key
Pin 6 = None/Unknown
Pin 7 = VCC
Pin 8 = None/unknown
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AngeloGomes
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Re: Edwards Active Gauge Controller Teardown

Post by AngeloGomes »

As none of membrane keys are working, I suppose the VCC line is broken somewhere. The plastic flat cable is not so easy to fix and after digging inside the display I messed up a bit, but I realize it is better to replace every membrane key separetely. As soon as individual membrane keys arrive from aliexpress I will test the idea and post the results here, meanwhile I have to work with the mechanical switches as the main problem now is the AGC not recognizing the gauges.
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AngeloGomes
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Re: Edwards Active Gauge Controller Teardown

Post by AngeloGomes »

Below is the power Board.

There are three stages here: one for 5V, 15V and 24V.

the voltages go to the mainboard through soldered wires, the white ones at left. Here in Brazil, we call this as "dirty economy". A power connector at the mainboard should be right choice !

Image
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AngeloGomes
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Re: Edwards Active Gauge Controller Teardown

Post by AngeloGomes »

Now the mainboard

Image
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AngeloGomes
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Re: Edwards Active Gauge Controller Teardown

Post by AngeloGomes »

As you can see at right, just behind the RJ45 connectors (where the gauges are to be connected) there are a lot of varistors, they are 5 for each port.

At top left the power wires and behind them the flat cable for the display board.

This controller uses the voltage between pins 4 and 5 of the RJ45 connector to identify the gauge. Every Edwards Gauge has between pins 4 and 5 a resistor ID, for identification purpose.

I was expecting to find an ADC chip in this board, but I think my AGC is too old and the AGC circuitry was implemmented in a hard way at that age !

Next photos, I will focus on the IC's on this board.
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AngeloGomes
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Re: Edwards Active Gauge Controller Teardown

Post by AngeloGomes »

My AGC does not have the Serial COMMS option. As I found a RS232 CI on the board, I was wondering if the connector is the only part missing for this option.
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