I've got 3 of these boards now and had no luck finding somone with a good one so I'm biting the bullet and going to have a go at component level.
I've worked out most of what i think is failed when I stumbled across a reading across the 5v reg IC16771 VAD +5V between gnd and out of 5.2ohms. The other 2 boards have 2 & 8 ohms.
This seems too low and would exceed what the little reg would handle I believe.
Through elimination I've tracked it to what I believe is a 5pin, 2 input NAND gate. It has a marking "HA" which I believe I've tracked down as a 74HC1G00GW, SOT353 .
I've confirmed out of cct the resistance between gnd and Vcc to the same 5.2 ohms and there is no longer that resistance present on the 5v reg.
Just looking for advice or confirmation of my findings. Does anyone know what you'd expect to see across the nand gnd/Vcc?
If I do get lucky and get one going I'll be adding all my research down the track.
The pictures are one out of the manual & the other is from the datasheet for what I believe this is.
I've worked out most of what i think is failed when I stumbled across a reading across the 5v reg IC16771 VAD +5V between gnd and out of 5.2ohms. The other 2 boards have 2 & 8 ohms.
This seems too low and would exceed what the little reg would handle I believe.
Through elimination I've tracked it to what I believe is a 5pin, 2 input NAND gate. It has a marking "HA" which I believe I've tracked down as a 74HC1G00GW, SOT353 .
I've confirmed out of cct the resistance between gnd and Vcc to the same 5.2 ohms and there is no longer that resistance present on the 5v reg.
Just looking for advice or confirmation of my findings. Does anyone know what you'd expect to see across the nand gnd/Vcc?
If I do get lucky and get one going I'll be adding all my research down the track.
The pictures are one out of the manual & the other is from the datasheet for what I believe this is.
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