I have a problem with the battery life on this cart . :redcart:
It come with battery and after about a month the battery dies and my save gone.
So a I put the new fresh one, and after no more than 2 months the same is happen?
What to do?
Why batteries die so quickly ?
do you have a multimeter which is capable of measuring low current around?
just measure the current consumption from the battery. it should be within the specs you can find in the datasheet for the memory chip.
thanks for the idea :D
I only measured the voltage when noticed that my save is gone for the second time, and the voltage was around 100mV totally drained battery , I did not think about current, but hmm how to measure mA from it ? I have to solder wires and put the ,multi-meter between the electric chain.
Which chip is the memory one ? :upsetroll:
To meassure current you would have set your multimeter to amperemeter mode and connect it in series in the circuit, unlike voltmeter that must be connected in parallel (connecting an amperemeter in parallel may damage it). I guess you could remove the battery and use crocodile clips on the battery holder poles. Then find some way to hold the battery so it's also in series.
You don't have to worry about the chips.
I measured the the current so it is draining 18 mA is it normal or is it 0.18mA I can not figure out ,when I am on range before 20mA it show to me "1" witch men that I am out of range, so I change it to 20 mA range.
BTW
I used a mini magnet to attach the black crocodile to the negative bottom of the battery :)
:) Whoever designed and assembled this board wasn't aware of retention mode. NES wiki covering this question, just make long story short.
1)Diodes must be with low voltage drop. Shottcky diodes are just fine.
2)In retention mode V at /CE must be no more than 0.2V less than Vcc
3)Exactly this PCB have SMD resistor 4.7K(472), connected as pull up /CE to voltage regulator !!!, but when cart is unpowered this resistor preventing retention mode(draining current from battery to ground thru voltage regulator) - you can see 1.07V at /CE is not right.
FAMICOM_87 was quite lucky - when unpowered, mapper hold it's pins in high impedance, so removing 4.7K SMD resistor and replacing extra soldered resistor with 10K solved problem.
There is more carts with similar "chinese design" out there floating around.
Quote from: FAMICOM_87 on July 02, 2017, 07:08:41 am
I measured the the current so it is draining 18 mA is it normal or is it 0.18mA I can not figure out ,when I am on range before 20mA it show to me "1" witch men that I am out of range, so I change it to 20 mA range.
it's showing 0.18mA and this measuring isn't accurate due to lack of 2m range.
0.18mA is way too high anyway, expected value should be less than 0.05mA (50uA)
Post Merge: July 13, 2017, 11:46:12 am
Quote from: 80sFREAK on July 13, 2017, 07:55:46 am
1)Diodes must be with low voltage drop. Shottcky diodes are just fine.
2)In retention mode V at /CE must be no more than 0.2V less than Vcc
3)Exactly this PCB have SMD resistor 4.7K(472), connected as pull up /CE to voltage regulator !!!, but when cart is unpowered this resistor preventing retention mode(draining current from battery to ground thru voltage regulator) - you can see 1.07V at /CE is not right.
i would add another important point to your list.
4) SRAM chips were misplaced one by another. LL chip should be used to save states (LL means more than twice lower power consumption against a regular L chip)
Many thanks to 80sFREAK !!!
the problem is solved so here are the resolute :)
And now the consummation is
(Notice that I am in 20micro range, not 20mili range like the last time!
And multi-meter shows 0.16)
https://drive.google.com/file/d/0B-MgC_wqs-WcNVRaLW40ZTA1ODQ/view
PCB before:
https://drive.google.com/open?id=0B-MgC_wqs-WcVi1acXJZZjdVYzQ
PCB after:
https://drive.google.com/open?id=0B-MgC_wqs-WcaGk5S1ExWkRPYjg
And voltage on Vcc , and pin /CE are about 3V, not like the last time
https://drive.google.com/open?id=0B-MgC_wqs-WcTUpyT0laRVRqSGM
https://drive.google.com/open?id=0B-MgC_wqs-WcSzF2dG5VR2ZxaUE
How about a more basic issue, namely the lack of 5v chips on this board? According to this, these things are dangerous : https://db-electronics.ca/2017/07/05/the-dangers-of-3-3v-flash-in-retro-consoles/
Quote from: famifan on July 13, 2017, 11:40:46 am
i would add another important point to your list.
4) SRAM chips were misplaced one by another. LL chip should be used to save states (LL means more than twice lower power consumption against a regular L chip)
Not critical.
Quote from: Great Hierophant on July 13, 2017, 09:29:47 pm
How about a more basic issue, namely the lack of 5v chips on this board? According to this, these things are dangerous : https://db-electronics.ca/2017/07/05/the-dangers-of-3-3v-flash-in-retro-consoles/
You have to choose - you want it
cheap or you want it
proper.
It amazes me that so many are skimping on such a basic thing as not using components out of their range as is. OK that cheap Chinese multicarts are poorly designed doesn't surprise me, and Krikzz do makes sloppy design choices for his Everdrives sometimes, but still.
Hmm Famicom Everdrive, Turbo V2 Everdrive and SD2SNES seems to all be allright at least. Those are the ones I use on that list.
Quote from: P on July 14, 2017, 01:35:38 am
It amazes me that so many are skimping on such a basic thing as not using components out of their range as is. OK that cheap Chinese multicarts are poorly designed doesn't surprise me, and Krikzz do makes sloppy design choices for his Everdrives sometimes, but still.
Hmm Famicom Everdrive, Turbo V2 Everdrive and SD2SNES seems to all be allright at least. Those are the ones I use on that list.
this sound not good, what about NES Power Pack ? :redcart: ??? :upsetroll: