bitrot-alpha
commented
11 months ago Board photos
Closed bitrot-alpha closed 11 months ago
bitrot-alpha
commented
11 months ago Board photos
bitrot-alpha
commented
11 months ago Aliexpress seller suggested I solder the USE_BATT jumper (JP402 on this version of the board) then set the time, and then unsolder the jumper. This didn't do anything useful.
mrehkopf
commented
11 months ago USE_BATT has nothing to do with that, in fact it has no effect at all. Looks like the seller has no idea what they're talking about 😁 RTC failure seems commonplace for those carts, I once fixed one by replacing the load caps on the RTC crystal (C408+C409), they're supposed to be 15pF but you might want to try 12pF or 10pF as well.
But in all honesty it should be the seller's responsibility, not yours nor mine ;)
mrehkopf
commented
11 months ago Also yikes, what's with the cracked coil on the switching regulator? 😬
bitrot-alpha
commented
11 months ago Thanks for getting back to me! I'll try ordering some SMD caps I guess. 0608 size?
They shipped the cart in a pretty thin bubble mailer. When I opened the cart up for the first time, I wondered why a tiny little piece fell out, turns out it was that missing chunk of the coil haha.
mrehkopf
commented
11 months ago Looks like 0603. Oh dear. Good luck. 🥲
bitrot-alpha
commented
11 months ago Received my replacement caps today. I tried the 10pf and that didn't fix it.
15pf did work though! I wish I had an ESR meter to check the ones I removed..
Hi,
Sorry in advance if you don't support Chinese clones.
Board info
I bought a clone cart from Aliexpress, and it appears to work fine except that the RTC does not tick when the cart is powered off. It seems to hold whatever time I set it to, but it resets to that exact set time when the cart is powered off or SNES reset is triggered.
The test firmware showed no problems with the cartridge except for the RTC.
I took apart the cartridge to check the battery voltage, and it is at 3.0 volts (Not a CR2032, they used the smaller CR1220 instead). I tried removing the battery and waiting 30 seconds before re-installing it. Is there some other troubleshooting steps I could do? I can send photos of the board.
I am somewhat proficient in SMD soldering. Would replacing the RTC chip do anything useful?
Test firmware log: