SX-1+ Mini with MegaFlashRom SCC+ SD problem(s)

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By tooloud

Rookie (25)

tooloud's picture

22-11-2020, 02:06

@SkalTura, my Megaflashrom SCC+ SD works fine in 1st slot (top) of SX1mini+. I have disabled internal microsd slot and summing - I'm using set to on just on #2-#3 dipswitches (the rest is set to off). I do not have this SX-1mini for more then a few days, but - as for now - all works as expected. If any to test and compare - just ask me.

By SkalTura

Champion (264)

SkalTura's picture

23-11-2020, 14:42

@tooloud, I also have only dipswitches 2 and 3 to on and the rest off, and MFR inserted in the top slot.
But mine (or at least, the combination) is very unstable...

By SkalTura

Champion (264)

SkalTura's picture

03-12-2020, 15:11

Okay, new update...

Found a few more dodgy soldering, so ended up re-soldering every single components and chip pin by hand.
Sadly, still the same issues.

Then I replaced the pull-up resistors array for the 10k version.
A bit more stable, but still fails.

Added a larger capacitors over the 5V power regulator.
Again a bit more stable, but still fails.

However...
Ice-cold start (meaning having the power completely off for more than a minute), makes the MFR startup normally every single time now.
Shorter cold starts, or warm starts (reset button), still fails.

So, we have some improvement...!
Still find it strange that the problem only seems to happen with the MFR and not with other cartridges...

By KdL

Paragon (1363)

KdL's picture

03-12-2020, 15:28

I have a very recent discovery to report to you. The SX-1 and SX-1 Mini+ external slots appear to have a slight nominal voltage deficit due to the length of the power cable. So I also recommend that you test a power supply with a 50cm cable.

By SkalTura

Champion (264)

SkalTura's picture

03-12-2020, 16:17

KdL wrote:

So I also recommend that you test a power supply with a 50cm cable.

That was one of the first things I tried when testing with different cables and power supplies.
Cable I ended up using is only 30cm's long, and thick wire (0.75mm²).
So that's not the issue I think.

What I could try is to solder a capacitor (for example 100μF) directly over the power pins of the cartridge slot...?

By KdL

Paragon (1363)

KdL's picture

03-12-2020, 20:21

I think you should try the MFR on another OCM machine like Zemmix Neo to see if the problem persists. Making random changes to the SX-1 Mini+ may compromise the use of other cartridges.

10K pull ups are wrong, for example the Goonies "R" Good Enough cartridge and others may not work with those pull ups.

>>What I could try is to solder a capacitor (for example 100μF) directly over the power pins of the cartridge slot...?
I don't have a cartridge like yours to test, so I don't know. I only have an old MFR first version without SD card.

By SkalTura

Champion (264)

SkalTura's picture

04-12-2020, 07:59

KdL wrote:

I think you should try the MFR on another OCM machine like Zemmix Neo to see if the problem persists. Making random changes to the SX-1 Mini+ may compromise the use of other cartridges.

Don't have many other cartridges, and was only planning to use the MFR in the SXmini...
So for now I will try some other options, including removing the extra memory from the MFR, just to make sure that that is not causing the problem.

By SkalTura

Champion (264)

SkalTura's picture

05-12-2020, 08:36

A bit off topic maybe...

I really like the multirom menu for the MFR, so you have all your games visible and can select them with a joystick.
Can this same multirom menu be loaded from an SD card directly without using the MFR and using one of the SX-1 mini+ slots as a megaram ?
Been looking at SofaRom, but that's more a directory structure instead of a real menu...

By Guillian

Prophet (3382)

Guillian's picture

05-12-2020, 11:50

The MultiROM menu will not work on a MegaRAM. It uses hardware features of the MFR SD.

By SkalTura

Champion (264)

SkalTura's picture

10-12-2020, 10:54

Okay, new update

I found that when I have the MFR inserted, and (for example) my FM-Pak in the other slot, the SX-1Mini+ was also a lot more stable then with only the MFR inserted.
That got me thinking... What is the effect if I jumper the SX as a MageSCC+ for the slot that I'm not using.
And indeed, more stable.

So, my setup is now:
- MFR in slot 2 (flat laying slot)
- Extra capacitor 470μF soldered over the +5V (USB connector)
- Jumper settings 2, 3, 4 and 7 to ON, rest is OFF

With this setup it startsup normally 90 out of 100 times, both with cold or warm starts.
Still not sure why, but this is the most stable setup I found so far.

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