Subject:
|
Re: assembling I/C board
|
Newsgroups:
|
lugnet.robotics.handyboard
|
Date:
|
Sat, 19 Jul 1997 03:34:02 GMT
|
Original-From:
|
Fred G. Martin <fredm@media.mit.%AntiSpam%edu>
|
Viewed:
|
740 times
|
| |
|
|
> I've encountered some problems assembling the interface/charger board.
> After installing the 16-pin socket for U16 and the capacitors and then
> mounting the MAX232 chip, I then applied power to the board. But, the PWR
> LED did not lit up and the voltage at pin2 of U16 did not read +10
> volts.
Well, if the power LED didn't light, then you don't have power to the
MAX232 chip (unless the LED is installed backward or broken).
It sounds like you've already skipped ahead without passing the first
set of tests, which I've copied from the assembly instructions below.
Why don't you perform these tests and report on your status.
-Fred
Testing
Apply power to the Interface/Charger Board using the 12 volt DC
adapter by plugging into J11. The power indicator LED, labelled
``PWR'' (LED13R) should light.
Now measure the board voltage. A convenient spot is the holes for
component C14. Place the voltmeter's black lead onto the square hole
(the minus terminal) and the red lead onto the round hole (the plus
terminal). You should see a voltage between 4.9 and 5.1 volts.
If the voltage reading across the C14 terminals checks out, proceed to
the next assembly step; otherwise, follow the debugging instructions
below.
Debugging
If the LED does not light, or if no voltage is present at the C14
terminals, verify that the DC power adapter is providing power by
measuring the voltage at the two terminals labelled ``~'' on D2. If
there is no voltage here, then the adapter is not working (check that
it is plugged in).
If power is present, check for voltage on the
output terminals of D2. There should be between 15 and 18 volts DC
across the terminals marked + and -. If there is no power here, then
D2 is suspect.
If D2 is outputting the correct voltage, then U17 is suspect. Check
that it is installed correctly. If it is very hot, there is a good
chance it's installed backward.
Finally, check the polarity (orientation) of the two ripple-smoothing
capacitors (C15 and C16). If either of these are installed backward,
the circuit will not function.
------------------------------------------------------------------------
> I'm quite positive the orientation of the capacitors is correct.
> The test to check the MAX232 chip's ability to transmit data did check out.
> Anyone know what might be wrong?
>
> thanks,
> phet
>
>
|
|
Message is in Reply To:
 | | assembling I/C board
|
| Hi, I've encountered some problems assembling the interface/charger board. After installing the 16-pin socket for U16 and the capacitors and then mounting the MAX232 chip, I then applied power to the board. But, the PWR LED did not lit up and the (...) (27 years ago, 18-Jul-97, to lugnet.robotics.handyboard)
|
2 Messages in This Thread:
 
- Entire Thread on One Page:
- Nested:
All | Brief | Compact | Dots
Linear:
All | Brief | Compact
|
|
|
|
