Hello, I just completed a QMX build and had a power-up issue.
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I used a lab PSU at 7V initially; QMX draws ~150 mA right away - not proper.
But at the same it did power-up and display lights up.
So I tried USB connection and was able to flash the firmware successfully.
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- it self-turns on;
- MCU probably thinks it is underpowered: as soon as it boots and displays normal view, it shows "Shut down!" and cycles;
- display backlight blinks randomly - again, power stability issue?
- draws too much power: I dared to try to turn it on with 9V and got almost 1A consumption.
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I double-checked all components, especially on power boards and found no fried parts or soldering issues.
I also checked the 8-pin power board connector; it is the only board getting the incoming voltage, is this correct?
I don't see constant grounding on PWR_ON pin (unless left knob is pressed).
There's no measurable impedance between power and ground on the power connector if the power board is removed.
I also checked for notorious Q103/Q104 short before building - not a known V4 problem, but just in case.
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What else I can check? I assume the problem is within 8-pin power board; could it be somewhere else?
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Thank you in advance.
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