It was just easier to use a rechargeable one.
Are you using LIR2032 or ML2032?
Are you using LIR2032 or ML2032?
I wouldn't recommend using FRAM as a substitute for SRAM because it has a finite number of accesses before it becomes unusable. Backup ram is accessed far more frequently by the bios for various functions as opposed to a low access memory device like a memory card.
Ok, good tip. Thanks
WHERE THE FUCK HAVE YOU BEEN!?
After some advice, I replaced R36, D5 and D6 with these (from RS Components) just in case my originals were dodgy:
Toshiba 45V 100mA, Diode, 2-Pin SOD-323 1SS357(F)
301Ω 0805 Metal Film SMD Resistor ±0.1% 0.125W - ERA6AEB3010V
KEMET C0805C104K4RACTU 100nF MLCC 16V dc ±10% Tolerance SMD
Still noticing drain. Been using an LIR2477 (about the same capacity as C2032) but eventually the voltage gets too low then would stop charging.
I have a question for James or shadowkn55 - would replacing the backup ram with these work (no battery required)?
https://au.element14.com/cypress-semiconductor/fm1808b-sg/f-ram-non-vol-256kbit-soic-28/dp/2772906
I rebuilt my charging circuit, and it is working again, but yes, again draining.
I charge the battery up to 3,2 V, and when I disconnect it, it drains 0.01 V every 5 seconds.
So in less than half an hour, it' s dead.
I have another mv1c which works good, and the battery looses voltage at a decent rate.
So it appears that this problem does not happen to every mv1c.
What I've found is that, without powering the board (only with the battery fully charged), the difference of voltage between +5V and ground (measured in the jamma connector) is 0.25 V. This is extremely weird. And it does not happen with the other mv1c that works properly (difference of voltage is 0V, as it should be).
Can you please check if you too have this small voltage between +5V and ground?
Can you please check if you too have this small voltage between +5V and ground?
Hey mate, I think my battery is completely fucked. It drains by about half as soon as I turn the power off. I'll get a new battery and test again.....
I guess I may have burnt it while doing the battery mod. I'll replace it.That means the 74HC32 needs to be replaced.
If that is the case, we may have found the component that is draining the battery.I've seen several cases where pins 12 and 13 are outputting voltage even though those pins are inputs. Pins 12 and 13 are connected to the reset circuit which involves a pull-up to the main vcc. Which effectively try to make the backup battery power the entire board.
I rebuilt my charging circuit, and it is working again, but yes, again draining.
I charge the battery up to 3,2 V, and when I disconnect it, it drains 0.01 V every 5 seconds.
So in less than half an hour, it' s dead.
I have another mv1c which works good, and the battery looses voltage at a decent rate.
So it appears that this problem does not happen to every mv1c.
What I've found is that, without powering the board (only with the battery fully charged), the difference of voltage between +5V and ground (measured in the jamma connector) is 0.25 V. This is extremely weird. And it does not happen with the other mv1c that works properly (difference of voltage is 0V, as it should be).
Can you please check if you too have this small voltage between +5V and ground?
OK, keep us informed please. We might find something useful in your problem.
I guess I may have burnt it while doing the battery mod. I'll replace it.
Anyway, can you please explain why you think it is damaged?
Could be a bad diode letting voltage through