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Problems with new FlashROM 99 board


AuTomato

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The FlashROM99 board that I ordered from the last batch came earlier this week and much to my disappointment I can't seem to get it to read any SD cards. No matter what I do I just get the two blinks on the LED forever which is supposed to indicate an unreadable filesystem.

 

So far I have tried five different SD cards from five different manufacturers, all class 4 and up. I've tried both FAT16 and FAT32, and still nothing. Did I just get a bad board or does anyone else have any ideas?

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The FlashROM99 board that I ordered from the last batch came earlier this week and much to my disappointment I can't seem to get it to read any SD cards. No matter what I do I just get the two blinks on the LED forever which is supposed to indicate an unreadable filesystem.

 

So far I have tried five different SD cards from five different manufacturers, all class 4 and up. I've tried both FAT16 and FAT32, and still nothing. Did I just get a bad board or does anyone else have any ideas?

 

Was it a pre-built card or did you build it? I had a similar issue when i built one of mine and i found out one of my tactile switch pins was grounding out on the SD Card connector housing.

Edited by Shift838
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Check the 3v line on the sdcard reader.. it should be around 3v.. if its too high it wont read the cards

 

Greg

If I'm reading this image correctly, the 3v pin is second from the right and ground is the pin furthest to the right when looking down on the flashrom board:

https://github.com/endlos99/flashrom99/raw/master/doc/assembly.jpg

 

Am I correct about that?

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Was it a pre-built card or did you build it? I had a similar issue when i built one of mine and i found out one of my tactile switch pins was grounding out on the SD Card connector housing.

I got it pre-built from arcade shopper, the reset switch definitely isn't grounding out on the SD card cage though, the gap is actually fairly big compared to the boards that I've seen pictures of online, and there's plenty of clearance.

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as long as that voltage is over 4 it will not work.. Sorry for the problems..

 

I am happy to take a look at it for you but unfort you'd have to ship it back to me.

 

Greg

It sounds like that's what we'll have to do. I'll contact you via email to make arrangements.

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as long as that voltage is over 4 it will not work.. Sorry for the problems..

 

I am happy to take a look at it for you but unfort you'd have to ship it back to me.

 

Greg

 

Hey Greg,

 

The plot thickens--but in a good way. I was able to snag one of the most recent batch of NanoPEBs which came today and just for the hell of it I tried the flash cart again with that hooked up instead of my standalone 32K expansion and much to my surprise, the flash cart is now working reliably. If I switch back to the standalone 32K expansion it reads 4.5-4.8v on the 3v line of the SD card slot, and with the NanoPEB hooked up it reads almost precisely 3.3v.

 

The standalone 32K expansion had been working fine for a while with RXB and the some homebrew stuff I have put on an UberGROM board, so I'm not really entirely sure what the deal was, but it seems to be okay now.

 

Thanks again for the troubleshooting advice!

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I wonder if we should get a list of the 32K sidecars that have been tested with the FlashROM together. That way there is a single place to look when new folks turn up looking for answers. There were a lot of sidecars out there, although the numbers go down some when you eliminate the two or three company name changes some of them had.

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I wonder if we should get a list of the 32K sidecars that have been tested with the FlashROM together. That way there is a single place to look when new folks turn up looking for answers. There were a lot of sidecars out there, although the numbers go down some when you eliminate the two or three company name changes some of them had.

Mine's just the modern JediMatt one. I'm not doubting the craftsmanship, but there could certainly be something ever so slightly wrong with my machine that combined with perhaps a different power draw or something like that causes the voltage to be too high. I can't remember if I tried it with the card running on an external power supply, but that might be worth trying just to see.

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There is plenty of electronics theory I don't know yet... Power Supply is definately a weak-ness for me.

 

But, the SPI SD Card reader attached to the flashrom is given 5v, and is supposed to have a regulator on board, that drops that to 3.3v. They also typically have a logic level converter on them that must be powered by 3.3v that comes from the onboard voltage regulator. I have read that this 3.3v regulator is very important. It is said that SD Card readers do not work well with resister based voltage dividers.

 

All of my testing of the 32k card have been with the FlashROM99. But 90% of that with the power coming off of the sideport itself.

 

There are two varieties of my 32k card out there.

  • Rev 2 boards, have a jumper wire on the back, and an 74LS245 with Alliance 62256 SRAM chips. These use about 65ma.
  • Rev 3 boards, no jumper, it has been revised into the pcboard layout, and 74HCT245 with Cypress 62256 SRAM. These use about 25ms.

AuTomato? and Greg? Is there a commonality there too? Are you both having trouble when combined with a Rev 2 32k board?

 

-M@

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There is plenty of electronics theory I don't know yet... Power Supply is definately a weak-ness for me.

 

But, the SPI SD Card reader attached to the flashrom is given 5v, and is supposed to have a regulator on board, that drops that to 3.3v. They also typically have a logic level converter on them that must be powered by 3.3v that comes from the onboard voltage regulator. I have read that this 3.3v regulator is very important. It is said that SD Card readers do not work well with resister based voltage dividers.

 

All of my testing of the 32k card have been with the FlashROM99. But 90% of that with the power coming off of the sideport itself.

 

There are two varieties of my 32k card out there.

  • Rev 2 boards, have a jumper wire on the back, and an 74LS245 with Alliance 62256 SRAM chips. These use about 65ma.
  • Rev 3 boards, no jumper, it has been revised into the pcboard layout, and 74HCT245 with Cypress 62256 SRAM. These use about 25ms.

AuTomato? and Greg? Is there a commonality there too? Are you both having trouble when combined with a Rev 2 32k board?

 

-M@

 

mine is the original board from day 1 that you gave me to test, the smallholes one :)

 

Greg

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mine is the original board from day 1 that you gave me to test, the smallholes one :)

 

Greg

 

That is the rev1 board ( printed on the pcboard ). It has the same electrical characteristics as the Rev 2 boards, a single jumper wire to get power to the +5 to VCC on most of the chips, and the hungrier chips. 65ma. By the way, the chips can be swapped for the same chips as Rev 3 boards if you want it to run lower power. You are the only one besides myself with a Rev 1 board... :)

 

Greg, I can get you a pair of the lower power chips, and maybe we can see if that eliminates the problem for you? You are using external power, so this is sort of grasping at straws... but If there is something about my board that is causing the voltage on the FlashROM input into the SPI SD Card adapter to be too low, maybe the regulator there is not performing correctly? Some regulators have minimum input voltages or they fall back to no regulation... Or at least that is the impression I have. A little process of elimination never hearts.

 

-M@

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There is plenty of electronics theory I don't know yet... Power Supply is definately a weak-ness for me.

 

But, the SPI SD Card reader attached to the flashrom is given 5v, and is supposed to have a regulator on board, that drops that to 3.3v. They also typically have a logic level converter on them that must be powered by 3.3v that comes from the onboard voltage regulator. I have read that this 3.3v regulator is very important. It is said that SD Card readers do not work well with resister based voltage dividers.

 

All of my testing of the 32k card have been with the FlashROM99. But 90% of that with the power coming off of the sideport itself.

 

There are two varieties of my 32k card out there.

  • Rev 2 boards, have a jumper wire on the back, and an 74LS245 with Alliance 62256 SRAM chips. These use about 65ma.
  • Rev 3 boards, no jumper, it has been revised into the pcboard layout, and 74HCT245 with Cypress 62256 SRAM. These use about 25ms.

AuTomato? and Greg? Is there a commonality there too? Are you both having trouble when combined with a Rev 2 32k board?

 

-M@

Mine's a Rev. 3

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I just built and tested a new board with a different model SDcard reader and it's working 100% on my problem 4/a... so I'm really thinking it's the voltage regulator on that other sdcard reader that's the real problem. Happy to swap it out for you if you want to send it back..

 

Greg

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Hello all,

 

I have 2 of the 32k Sidecar Rev.3 boards (Rev 3 boards: no jumper, it has been revised into the pcboard layout, and 74HCT245 with Cypress 62256 SRAM. These use about 25ma.)

 

I always use them in conjunction with a FlashROM99 board.

 

I have tried on two different TI's and also with 2 different Flashrom99 boards, without issue.

 

Cheers,

Shane.

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