Hi, after building my "Power Distribution and Communications Board - v1.1", i am trying to test the voltage as described in the section "Debugging your serial connection". But I am getting different values. I have controlled my board, but I cannot find a miswiring or short. I am using an ATX power supply, which needs a resistor to switch on (this could not be the reason for the different measure, or?). I put the resistor in the power connector for a module. The Power Supply is delivering a voltage of 9,3V (messured at P1). And I am using the variant with the MAX202 (is this the reason?) and with 0.1uF for C2-C5. The device is not plugged into the PC and the communication connectors are empty. From the documentation the values should be: "Pin 15 to 16: 5V. A mismatch suggests a power supply or 7805 issue. Pin 15 to 14: -7 to -15V. A mismatch suggests a short on the board or a miswiring of the cable. Pin 15 to 13: 0V. A mismatch suggests a miswired cable. Pin 15 to 12: 5V Pin 15 to 11: 4 to 4.5V. " My measurements are: Pin 15 (-) to 16 (+): 5,1V Pin 15 (-) to 14 (+): +6.7V ! PIN 15 to 13: 0V PIN 15 to 12: 5,09V PIN 15 to 11: 0V ! Have someone an idea what could be wrong? thanks andreas https://reprap.org/forum/read.php?13,2329,2329#msg-2329 Tue, 19 May 2026 06:46:48 -0400 Phorum 5.2.23 https://reprap.org/forum/read.php?13,2329,2336#msg-2336 https://reprap.org/forum/read.php?13,2329,2336#msg-2336 ZachHoeken Controllers Tue, 05 Jun 2007 17:46:47 -0400 https://reprap.org/forum/read.php?13,2329,2333#msg-2333 https://reprap.org/forum/read.php?13,2329,2333#msg-2333
ZachHoeken Wrote:
-------------------------------------------------------
> perhaps you are measuring the voltage backward?
> the reverse is about -7v. also, are you testing
> with the chip installed? i think these are
> supposed to be measured without the chip.
I tried several times in the described direction (Pin 15 (-) to 14 (+)). And the measurements are with the chip installed.
without the chip, I get 0V from Pin 15 to 14, 13,12,11,10,9 and 5V from Pin15 to Pin16.


>
> also, it would be helpful if you could post a
> detailed shot of your board, something might pop
> out to one of us.
sorry, I have no camera here. but I will try to organize one.

andreas]]> Anonymous User Controllers Tue, 05 Jun 2007 10:41:10 -0400 https://reprap.org/forum/read.php?13,2329,2332#msg-2332 https://reprap.org/forum/read.php?13,2329,2332#msg-2332 -9.5V between Pin 15(-) and 14(+). Between Pin 15 and Pin 11 I am still getting 0V.
Trying the echo test with minicom, everything looks good.
So I will try to get a other power supply.

andreas]]> Anonymous User Controllers Tue, 05 Jun 2007 10:28:44 -0400 https://reprap.org/forum/read.php?13,2329,2330#msg-2330 https://reprap.org/forum/read.php?13,2329,2330#msg-2330
also, it would be helpful if you could post a detailed shot of your board, something might pop out to one of us.]]> ZachHoeken Controllers Tue, 05 Jun 2007 10:22:27 -0400 https://reprap.org/forum/read.php?13,2329,2329#msg-2329 https://reprap.org/forum/read.php?13,2329,2329#msg-2329
after building my "Power Distribution and Communications Board - v1.1", i am trying to test the voltage as described in the section "Debugging your serial connection". But I am getting different values. I have controlled my board, but I cannot find a miswiring or short.

I am using an ATX power supply, which needs a resistor to switch on (this could not be the reason for the different measure, or?). I put the resistor in the power connector for a module. The Power Supply is delivering a voltage of 9,3V (messured at P1). And I am using the variant with the MAX202 (is this the reason?) and with 0.1uF for C2-C5.

The device is not plugged into the PC and the communication connectors are empty.

From the documentation the values should be:
"Pin 15 to 16: 5V. A mismatch suggests a power supply or 7805 issue.
Pin 15 to 14: -7 to -15V. A mismatch suggests a short on the board or a miswiring of the cable.
Pin 15 to 13: 0V. A mismatch suggests a miswired cable.
Pin 15 to 12: 5V
Pin 15 to 11: 4 to 4.5V. "

My measurements are:
Pin 15 (-) to 16 (+): 5,1V
Pin 15 (-) to 14 (+): +6.7V !
PIN 15 to 13: 0V
PIN 15 to 12: 5,09V
PIN 15 to 11: 0V !

Have someone an idea what could be wrong?

thanks
andreas]]> Anonymous User Controllers Tue, 05 Jun 2007 08:18:09 -0400