Troubleshooting
Re: Troubleshooting
The IR LED does indeed glow faintly now. Still no luck on getting the nixies or blue LEDs to light up. I will send you a pic of the board.
Re: Troubleshooting
Everything looks OK there.
What's the voltage on pin 10 of IC1 and does it vary slightly when something is near the IR sensor?. Also the voltages on the other 2 pins of IC3 would help.
What's the voltage on pin 10 of IC1 and does it vary slightly when something is near the IR sensor?. Also the voltages on the other 2 pins of IC3 would help.
Re: Troubleshooting
IC3 shows 0.1V / 0.0V / 0.1V for it's 3 pins
I'm not sure how to tell which pin is 10 on IC1. As I look down at the top of the board with the front of the nixies facing me, starting from the upper left end I get:
2.3 / 5 / 0 / .02 / 0 / .02 / 0 / 0 / 0
on the row nearest me starting from the left I get:
varies from .04-.2 in response to hand movement (hey, this must be pin 10) / 5 / 3.9 / 5 / 5 / 5 / 0 / 5 / 5
I'm not sure how to tell which pin is 10 on IC1. As I look down at the top of the board with the front of the nixies facing me, starting from the upper left end I get:
2.3 / 5 / 0 / .02 / 0 / .02 / 0 / 0 / 0
on the row nearest me starting from the left I get:
varies from .04-.2 in response to hand movement (hey, this must be pin 10) / 5 / 3.9 / 5 / 5 / 5 / 0 / 5 / 5
Re: Troubleshooting
The 5V supply to IC3 is missing. Check the voltage at either end of R14 and try removing C4 in case it's faulty.
Re: Troubleshooting
R14 reads 5v on the right side and the left fluctuates between .05 and .33
Should I replace C4 with another 10n ceramic capacitor?
Should I replace C4 with another 10n ceramic capacitor?
Re: Troubleshooting
Just remove it for now. Check R14 is still 100R not open and for shorts to ground on the 2 end pins of IC3. There should be 5V at both ends of R14.
Re: Troubleshooting
I removed C4 (unfortunately destroying it in the process, but that's no big deal) with no change. I've checked everything else I can think of and am not finding anything. Can you give me some pointers on exactly what to check?
Re: Troubleshooting
What were the readings across R14 and could you supply a photo showing this part of the board?.
Re: Troubleshooting
R14 checks out as 100R. I sent you an email with a couple of photos of the board.
Re: Troubleshooting
Looking at the bottom photo, there appears to be something between the top pad of IC3 and the unused pad next to it on the right (which is connected to the centre pin of IC3). It may be just dust, but that is the area the fault will be in. The 5V supply to the IR sensor is being shorted to ground.
Check the resistance between those 2 pads (it should read between many Kohms and infinity depending on your meter) and look for any bridge between those pads, the pads of C4 and the pad of R14 next to C4. scrape around them with a scalpel blade to make sure. You could remove IC3 just to make sure it isn't the fault but I haven't had one die yet.
Check the resistance between those 2 pads (it should read between many Kohms and infinity depending on your meter) and look for any bridge between those pads, the pads of C4 and the pad of R14 next to C4. scrape around them with a scalpel blade to make sure. You could remove IC3 just to make sure it isn't the fault but I haven't had one die yet.