AV Famicom artifact ram poblem

Discuss hardware-related topics, such as development cartridges, CopyNES, PowerPak, EPROMs, or whatever.

Moderator: Moderators

Post Reply
MaRCer
Posts: 3
Joined: Wed Feb 14, 2024 3:06 pm

AV Famicom artifact ram poblem

Post by MaRCer »

Hi.
AV Famicom from the very first batch - serial starts at 10002xx.
After 10 minutes of operation, artifacts begin on the screen. After restarting, Everdrive may show an error reading from the card, it may start scrolling through the menu itself, or it may simply not load. I've tried several versions of Everdrive that work without problems on another console. In the only regular cartridge - RAF World/Journey to Silius, after starting a level, it switches to the next level in a second and runs through all the levels before the credits. Test cartridges write - work ram error. All this after 10 minutes of work, before that everything works fine. I felt all the components on the board with my fingers - nothing above 30 degrees is heated.
I tried to change the capacitors, power adapter, 7805, HC373, both memory chips, PPU - nothing helped. I did not change only the CPU and bu3266. If the CPU can be removed from some old broken ordinary Famicom, then there is nothing to replace the bu3266/3270. And as I understand it, it's probably about him?
User avatar
krzysiobal
Posts: 1036
Joined: Sun Jun 12, 2011 12:06 pm
Location: Poland
Contact:

Re: AV Famicom artifact ram poblem

Post by krzysiobal »

Probably you need to either try replacing CPU or crystal resonator.
CPU is extremely freaky in terms of the clock amplitude. If it is too low, CPU stops working correctly (while PPU still works fine).
CPU can be also a culprit, as I had PPU that started to display fuzzy video after a few minutes.
You need to obtain either UA6528 (CPU clone) or any dendy CPU and add some extra clock cycle remove some clock cycles to make final clock the same as if it was divided by 12
Image My website: http://krzysiobal.com | Image My NES/FC flashcart: http://krzysiocart.com
User avatar
aquasnake
Posts: 515
Joined: Fri Sep 13, 2019 11:22 pm

Re: AV Famicom artifact ram poblem

Post by aquasnake »

whats the error code displayed on the screen?

for your reference:

#define ERR_UNXP_STAT 0x40
#define ERR_UNK_ROM_FORMAT 0x41
#define ERR_PATH_SIZE 0x42
#define ERR_NAME_SIZE 0x43
#define ERR_OUT_OF_MEMORY 0x44
#define ERR_GAME_NOT_SEL 0x45
#define ERR_REGI_CRC 0x46
#define ERR_MAP_NOT_SUPP 0x47
#define ERR_MAP_NOT_FOUND 0x48
#define ERR_INCORRECT_GG 0x49
#define ERR_NULL_PATH 0x4A
#define ERR_USB_GAME 0x4B
#define ERR_ROM_SIZE 0x4C
#define ERR_BAT_RDY 0x4D
#define ERR_BAD_NSF 0x4E
#define ERR_BAD_FILE 0x4F


#define FAT_DISK_ERR 0x01
#define FAT_NOT_READY 0x03
#define FAT_NO_FILE 0x04
#define FAT_NO_PATH 0x05
#define FAT_INVALID_NAME 0x06
#define FAT_NO_FS 0x0D

The above error codes are common to the edn8 series, but there may be individual code differences depending on the specific OS version.

If it shows "Unexpected error", then will be an FATFS error, edn8 OS can only recognize a portion, and all FATFS errors are as follows:

typedef enum {
FR_OK = 0, /* (0) Succeeded */
FR_DISK_ERR, /* (1) A hard error occurred in the low level disk I/O layer */
FR_INT_ERR, /* (2) Assertion failed */
FR_NOT_READY, /* (3) The physical drive cannot work */
FR_NO_FILE, /* (4) Could not find the file */
FR_NO_PATH, /* (5) Could not find the path */
FR_INVALID_NAME, /* (6) The path name format is invalid */
FR_DENIED, /* (7) Access denied due to prohibited access or directory full */
FR_EXIST, /* (8) Access denied due to prohibited access */
FR_INVALID_OBJECT, /* (9) The file/directory object is invalid */
FR_WRITE_PROTECTED, /* (10) The physical drive is write protected */
FR_INVALID_DRIVE, /* (11) The logical drive number is invalid */
FR_NOT_ENABLED, /* (12) The volume has no work area */
FR_NO_FILESYSTEM, /* (13) There is no valid FAT volume */
FR_MKFS_ABORTED, /* (14) The f_mkfs() aborted due to any problem */
FR_TIMEOUT, /* (15) Could not get a grant to access the volume within defined period */
FR_LOCKED, /* (16) The operation is rejected according to the file sharing policy */
FR_NOT_ENOUGH_CORE, /* (17) LFN working buffer could not be allocated */
FR_TOO_MANY_OPEN_FILES, /* (18) Number of open files > FF_FS_LOCK */
FR_INVALID_PARAMETER /* (19) Given parameter is invalid */
} FRESULT;

In most cases, the problem lies with fatfs, which may include damaged files or disk structures, abnormal SD/SPI clock line interference, and incompatible formatted file system
MaRCer
Posts: 3
Joined: Wed Feb 14, 2024 3:06 pm

Re: AV Famicom artifact ram poblem

Post by MaRCer »

Everything is fine with Everdrive, it works without problems on other consoles. The problem is with this console, after 10 minutes the problems start with regular cartridges. I sold it to another person, if he can fix it, I will write here, which helped.
Post Reply