Mega ST2 & SatanDisk, a nightmare

[jltursan]

After finishing some upgrades to my ST2: 4MB, TOS 1.04 and Int/Ext drive swapping I was eager to try a SatanDisk and finally enjoy a fine looking machine. No way, I have two Satan and none of them work, I mean, they work but they ended corrupting the SD, always, no SD survived the experience.

 

I've need to rewrite the SD countless times, rendering the device as totally unusable, half an hour and it doesn't boots anymore and all partitions are lost.

 

I know about the "bad DMA" fact; but I'm not sure if it's an absolutely true story or maybe there's a little myth around it; so, there's a way to make the SatanDisk work with these machines or I need to start thinking in dumping the Satan and use a Gotek drive instead (that's why I modded the drive swapping)?

[ParanoidLittleMan]

It is not at all sure that Satandisks are the problem at you.

Possible reasons:  crap SD cards - and there is lot of it on market, especially online.

Weak PSU for Satandisk.

Failure in ACSI port, DMA section in your  Mega ST.  Note that I don't talk about 'bad DMA chip' - that's case with early STEs, and that's true, with published bad versions of chip.

Overall unreliable work of your Mega ST. Should at least check it's power supply, and recap by need.

And yes, Satandisk can be problem too, but I really did not hear about much problems with them.

 

Satandisk works fine with all ST, Mega ST, STE (with good DMA chip), Mega STE, TT .

 

[Wally1]

Same thing happened to me.  Satdisk got all corrupted and did not work!  Twice, with two different.

How can you trust a name like that!?!

[jltursan]

Thanks!, the PSU has been already completely replaced by a picoPSU, seems fine enough but of course, I'm not sure if it's causing some strange havoc, maybe it's noisy?, could this have any effect in the ACSI reliability?. The Satan PSUs seems both powerful enough, what are the minimum Amps required for a Satandisk?, just to be in the safe side...

The SD cards are not branded indeed, so I'll try first to make some test with the best SD I can found.

 

Is there any other area where I can focus my tests? 

[Zogging Hell]

There is a resister patch you need to do if you have the original Satandisk (rather than Ultrasatan) which might fix your problems. I had partitiion loss with my Satandisks and my Mega ST 2 before I got it done, afterwards no problem. Its a fairly easy mod even if you have only a slight bit of soldering skills.

 

Check for the power off partition loss link on here..

 

http://joo.kie.sk/?page_id=86

[jltursan]

Although promising, this resistor fix hasn't worked for me, at least with the first Satandisk. After the third or fourth power cycle, the (cheap) SD was corrupted.

I'll try with the second unit and of course, swap my SD with a good one. I barely remember that time ago checked the DMA IC code and it was one of the "bad" ones, maybe my Mega is beyond cure :(

[Zogging Hell]

Hhhm I suppose the other things to check are..

 

The cable (ribbon cable) between the ST is ok - perhaps replace (again as Paranoid mentioned)?

 

Might be worth checking over the Satandisk for any soldering faults - iirc these were put together by hand, and a small bit of soldering error like dry solder joints, could cause an issue.

 

Try another Satandisk psu

 

Of course there are the general things like reseat socketed chips, recap motherboard and so on. I'd be surprised if the DMA chip is to blame, but perhaps replacing it might put your mind at rest

[jltursan]

Oh, well, seems that at least with my second Satandisk things are getting better. After applying the patch (it was a little different rev and required some special care) and using a Sandisk 1GB SD, looks like it's working stable now!

[+DarkLord]

Just curious - does your version always require a "soft" reboot after first starting?

 

When I had a Satandisk with my STacy, it always did. I've got an Ultrasatan now.

 

[jltursan]

Oh, it works so!, sometimes I need to reset the Mega to make the Satandisk being recognized;...but sometimes it boots the SD flawlessly. 

 

I haven't tested yet the other Satandisk, of course with the same good SD. I would love to definitely narrow the problem to the card; but to be 100% sure I would need to desolder the resistor and test the Sandisk with an unmodified device.

[jltursan]

...and the last small update, after testing for some days the second Satandisk, I'm getting the same stable behaviour, no hiccups; so I think that this could be a valid path to get some stability from your Satandisks (I mean, a good SD and the resistor fix).

 

So far, so good :-)

Edited October 28, 2019 by jltursan
Typo

[Zogging Hell]

On 10/22/2019 at 4:02 PM, DarkLord said:

Just curious - does your version always require a "soft" reboot after first starting?

 

When I had a Satandisk with my STacy, it always did. I've got an Ultrasatan now.

 

Mine always did with my STs, iirc it did not require one with the TT. Always presumed it was the TOS version, all the STs I tried it on were 1.02.

[+DarkLord]

Hmm. Mine was Tos v1.04, on the STacy. I don't remember trying it with TOS v3.06

when I upgraded it to a Pak board. I had the Ultrasatan installed by then.