Newb help needed please
- Thread starter Keith35
- Start date
Hmmm
So, assuming ground = 1.
1 - 2 = 336 k
1 - 3 = 336 k
1 - 4 = 336 k
Is that what you're reading?
e
Keith.
Could you check your results again please.
I've just tried another, working AXE027
No power, just the DMM, AXE027 and the bare socket.
Results.
Stereo tip > USB gnd ~ 1 ohm.
Stereo tip >> Ring c. 10.01 K
Stereo tip >> Sleeve c. 10.01 K
USB end.
Gnd > Data+ = c. 20 Megohms
Gnd > Data- = c.20 Megohms
Gnd > V+ = c. 20 Megohms
e
Could you check your results again please.
I've just tried another, working AXE027
No power, just the DMM, AXE027 and the bare socket.
Results.
Stereo tip > USB gnd ~ 1 ohm.
Stereo tip >> Ring c. 10.01 K
Stereo tip >> Sleeve c. 10.01 K
USB end.
Gnd > Data+ = c. 20 Megohms
Gnd > Data- = c.20 Megohms
Gnd > V+ = c. 20 Megohms
e
I've not been able to get any sensible resistance readings between 0v and the components. i'm going to solder a flying lead on to one of the earth points to get a good gonnection to the multimeter, but it doesn't help that I've not got a clue what the resistor arrays are there for 9or what readings i should get from them), nor do i know which of the legs of the picaxe chip are connected.
Can someone help me out by giving me a few specific things to look for?
I've had a close look at the board and there aren't any bridges. there are a few blisters in the plastic coating where i was a bit heavy handed with the solder. could solder have got underneath the plastic to make a bridge?
there's one tiny scratch between pins 17 and 18.
I've trimmed the legs on the transistors now. to be honest, i simply forgot about them when i was trimming the LEDs. i was just eager to get my clock going (more haste, less speed and all that?).
Any help gratefully received.
Cheers,
Keith
Can someone help me out by giving me a few specific things to look for?
I've had a close look at the board and there aren't any bridges. there are a few blisters in the plastic coating where i was a bit heavy handed with the solder. could solder have got underneath the plastic to make a bridge?
there's one tiny scratch between pins 17 and 18.
I've trimmed the legs on the transistors now. to be honest, i simply forgot about them when i was trimming the LEDs. i was just eager to get my clock going (more haste, less speed and all that?).
Any help gratefully received.
Cheers,
Keith
Can no-on else offer me any help? it'd be a shame to put the whole lot in the bin!
hippy
Ex-Staff (retired)
I'm not sure what to suggest. Plugging or unplugging a USB cable should not shut down the PC and it is particularly odd that it should shut down using one set of ports but not others. That suggests to me a PC / USB port problem rather than a faulty USB cable, that it shuts down the PC even without the AXE114S connected suggests theAXE114S is not the cause of the problem.
I've always been advised not to run resistance and continuity checks on active components such as chips and USB cables as results can vary and damage can occur if not done using suitable equipment. The best way to test the USB cable is using the Programming Editor Serial Test then using another PC ( with a hub where a damaged cable is suspected ).
As to checking the download resistors, this can be done by measuring the resistance with the 28X removed from the circuit from the RX pin on the download socket to the Serial In pin on the 28X ( should be 22K ) and to 0V ( should be 10K ). Download can be tested using an RS232 cable where the USB connection is suspect, or with a known working USB cable on another PC known to work with that cable.
I know how difficult and frustrating it can be trying to determine where a problem is when it is not known what parts of a system are working or not. The best appraoch is to test each component of the system against something known to be working. That way what is not a problem can be eliminated. At the moment it is not clear what is at fault, the PC, the USB cable or the AXE114S, and what has been damaged by any failure which has occured.
I've always been advised not to run resistance and continuity checks on active components such as chips and USB cables as results can vary and damage can occur if not done using suitable equipment. The best way to test the USB cable is using the Programming Editor Serial Test then using another PC ( with a hub where a damaged cable is suspected ).
As to checking the download resistors, this can be done by measuring the resistance with the 28X removed from the circuit from the RX pin on the download socket to the Serial In pin on the 28X ( should be 22K ) and to 0V ( should be 10K ). Download can be tested using an RS232 cable where the USB connection is suspect, or with a known working USB cable on another PC known to work with that cable.
I know how difficult and frustrating it can be trying to determine where a problem is when it is not known what parts of a system are working or not. The best appraoch is to test each component of the system against something known to be working. That way what is not a problem can be eliminated. At the moment it is not clear what is at fault, the PC, the USB cable or the AXE114S, and what has been damaged by any failure which has occured.