Difference between revisions of "LXR Troubleshooting"
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U3 is the first in the chain (connected to the AVR) and U11 the last. | U3 is the first in the chain (connected to the AVR) and U11 the last. | ||
| + | * measure continuity with a multimeter for the following pins: | ||
| + | ** pin 11 of each 595 IC should be connected to pin 19 of the AVR | ||
| + | ** pin 12 of each 595 IC should be connected to pin 18 of the AVR | ||
| + | ** pin 14 of U3 should be connected to pin 20 of the AVR (DOUT_DATA) | ||
| + | ** pin 9 of U3 is connected to pin 14 of U7 | ||
| + | ** pin 9 of U7 is connected to pin 14 of U9 | ||
| + | ** pin 9 of U9 is connected to pin 14 of U13 | ||
| + | ** pin 9 of U13 is connected to pin 14 of U11 | ||
...more to come | ...more to come | ||
Revision as of 08:16, 2 July 2014
General things to check
- Check the IC orientation
- Check if you did not put an IC in the wrong place (mixed up 74hc165 and 74hc595 for example)
- Are the ICs seated correctly in their sockets? No bend legs?
- Try re-installing the firmware from the SD-card
Buttons not working
The 74HC165 ICs are responsible for reading the buttons. If some or all of the buttons are not working, it is most likely due to an error with those ICs.
- check if all 165 ICs have the right orientation and are in the right location of the PCB (and not mixed up with the 595 ICs for example)
- check that all 165 ICs sit tight in their sockets. sometimes a leg can be bend below the ic.
- measure continuity with a multimeter for the following pins:
- pin 2 of each 165 IC should be connected to pin 28 of the AVR
- pin 1 of each 165 IC should be connected to pin 27 of the AVR
- pin 9 of U2 should be connected to pin 29 of the AVR (DIN_DATA)
- pin 10 of U2 is connected to pin 9 of U5
- pin 10 of U5 is connected to pin 9 of U6
- pin 10 of U6 is connected to pin 9 of U12
- pin 10 of U12 is connected to pin 9 of U10
- each of the 165 ICs controls 8 buttons. the groups are the following:
- U2: Seq. buttons 1-8
- U5: Seq. buttons 9-16
- U6: Select buttons 1-8
- U10: Start, Rec, Shift, Voice, Perf., Step, Load/Save
- U12: Voice buttons 1-7 and Copy button
LEDs not working
The 74HC595 ICs are responsible for the LED signals.
- U3 - Step LEDs 9-16
- U7 - Step LEDs 1-8
- U9 - Select LEDs 1-8 (Osc, AEG, Mod, etc...)
- U13 - copy LED + 7 VoiceLEDs
- U11 - Mode 1-4 + Rec,Tempo and Shift LED
U3 is the first in the chain (connected to the AVR) and U11 the last.
- measure continuity with a multimeter for the following pins:
- pin 11 of each 595 IC should be connected to pin 19 of the AVR
- pin 12 of each 595 IC should be connected to pin 18 of the AVR
- pin 14 of U3 should be connected to pin 20 of the AVR (DOUT_DATA)
- pin 9 of U3 is connected to pin 14 of U7
- pin 9 of U7 is connected to pin 14 of U9
- pin 9 of U9 is connected to pin 14 of U13
- pin 9 of U13 is connected to pin 14 of U11
...more to come
