SE/30 PDS Adapter Epic Blunder

[james_w]

@JDW I just did the exact same Epic Blunder, close to one year after you

Did you ever figure out a fix or find an easy way to test where the issue lay?

(One last note - it's not clear to me if I fried the Turbo 040 card or the adaptor card - my Turbo 030 card now won't work either, so I'm wondering if I did something to the adapter instead/as well as the accelerator)

 

[JDW]

@JDW I just did the exact same Epic Blunder, close to one year after you

Did you ever figure out a fix or find an easy way to test where the issue lay?

Tragically, no, I’ve not found a fix; and as evidenced by the lack of replies over the last year, everyone here appears stumped as well.  

I created the following to show what possibly was shorted:

View attachment 25617

I have no other accelerator I can use to test my TS Adapter, but I suspect it is still fine and the root problem lies on the 040 accelerator. I’m still shedding tears over that because I’ve not the faintest idea how to fix that valuable and rare card.

For the past year I held out hope that somebody might come along and offer some specific guidance for me on what to do next, but so far I’m still waiting. My wait may be eternal.

The only thing I can say for certain right now is that the TS adapter is fundamentally flawed in that it has no means of protection against PD cards being accidentally placed on the wrong connector. Not even a PTC fuse! That, to me is a serious design flaw. 
 

:-(

 

[Bolle]

Not even a PTC fuse!

That wouldn’t help, they are way too slow. As techknight already said earlier in this thread whatever silicone is connected to the higher voltage lines goes dead about instantly.

You could have left out the 12V altogether on the passthrough at the cost of certain PDS cards not working (mainly network cards I guess)

What confuses me a little bit is that the 030 card won’t work either in the case of @james_w.

I don’t see exactly why but chances are the accelerator survived and it’s indeed the adapter that dies. Only way that could happen if you ask me would be by the way that the 12V somehow make it into the GAL on there as well. That would only happen though if something went seriously wrong on the accelerator as well.

@james_w any chance you can test your accelerators in another machine?

 

[JDW]

@james_w any chance you can test your accelerators in another machine?

Interestingly, my name is “James“ and my last name starts with a W as well. What are the odds?

In the name of science and getting to the bottom of this once and for all with no more years and years of endless waiting around, I am willing to ship my TS Adapter at my expense to any responsible and trustworthy veteran member of this forum who has the means to test the adapter with a known good accelerator card.  In fact, I can include the 040 card too, if you have a machine in which you can test it, because I do not. The results of that test may assist the other “James“ in knowing which of his two cards is bad.

To be honest, I’m not sure how my reaction will be in either case. If the 040 card tests good in someone’s machine, that would be a tremendous relief to me; however, my TS adapter card cost me $200, so knowing that adapter is bad would still be a great loss.  Even so, the TS adapters are still built-in and sold whereas the 040 cards or not.

Anyone willing? Bolle?

 

[Bolle]

Interestingly, my name is “James“ and my last name starts with a W as well. What are the odds?

Haha, yes I thought of that as well already.

I can sure take a look at your Turbo040 and the adapter and test them both. I have got enough accelerators to test the adapter with one of my SE/30s and I got a IIci as well to check the Turbo040 on its own.

Didn’t you want to have a logicboard checked as well? We could combine all that

 

[JDW]

Bolle, PM sent.

 

[SE30_Neal]

Happy Christmas guys, i hope you fix the accelerator

 

[james_w]

@Bolle @JDW I have re-tested (with a less sleep-deprived brain) with my Turbo 030 and all is fine with the ProtoCache card  So at least I didn't screw *everything* up!

James, I know you know *a lot* more about electronics than I, so I think I've got an even smaller chance than you of rectifying my mistake. I'm working through getting over it.

When I have my IIci back out of storage I'm going to test the 040 again but I don't hold out much hope seeing as the 030 card works fine.

My assumption (with very little real digital electronics knowledge) that to fix it would involve replacing dead parts... but my understanding is that:
1) you have to figure out which parts are dead (I only have a multimeter and very low level of understanding)

2) the custom chips (ASICs?) that are likely dead would be nigh-on impossible to find replacements for

Not really sure what to say further than I could get another but I'm not sure I trust myself enough now!

 

[james_w]

Interestingly, my name is “James“ and my last name starts with a W as well. What are the odds?

Ha yes, we'd probably both find it more amusing if our common mistake hadn't resulted in likely dead Turbo 040 cards!

 

[james_w]

Happy Christmas guys, i hope you fix the accelerator

Ha thank you Neal! I think it is pretty unlikely but you never know...

 

[SE30_Neal]

Ha thank you Neal! I think it is pretty unlikely but you never know...

Fingers crossed! You’re in the right place... i keep looking and reading the latest so I’m hopeful for you  I’m afraid I have limited knowledge myself so just try and take it all in

 

[JDW]

@Bolle @JDW I have re-tested (with a less sleep-deprived brain) with my Turbo 030 and all is fine with the ProtoCache card  So at least I didn't screw *everything* up!

James, I know you know *a lot* more about electronics than I, so I think I've got an even smaller chance than you of rectifying my mistake. I'm working through getting over it.

Your statement above means you confirmed your TS Adapter is undamaged, correct?

There are varying degrees to electronics knowledge even among electrical engineers, and I give the humble nod to @Bolle as being far more practically savvy when it comes to vintage computing repairs.  Indeed, that is why I have obtained his very kind permission and cooperation to ship my TS Adapter and Turbo 040 (alongside 2 other boards) to him for detailed examination.  Bolle has the means to test the TS Adapter whereas I do not.  He also has some ideas about a possible chip-swap fix if my 040 is determined to be damaged.  My hope is that his findings can help you and others who find themselves newly initiated into our growing Epic Blunder Club.  

When doing a lot of parts swapping and testing in a vintage Mac (like my SE/30), the human brain can get so focused on doing things quickly it forgets the basics like never plugging in an accelerator PDS card into the top connector of the TS Adapter.  It's a blunder just waiting to happen to anyone, not just those of us with the name "James W." 

 

[james_w]

Your statement above means you confirmed your TS Adapter is undamaged, correct?

I don't have a TwinSpark adapter, mine is one of the ones that @Bolle kindly made and sold a couple of years ago. But yes, I've confirmed it is undamaged. Phew!

My hope is that his findings can help you and others who find themselves newly initiated into our growing Epic Blunder Club.  

I hope so too! Turns out you and I have different generations of Turbo 040 so the fixes (if hopefully figured out) will probably be different. I've learned you have a later board with one big ASIC, whereas I have the early board that is covered in chips, presumably all integrated into the ASIC later on. Mine is only 25mhz but does at least have the bolt-on cache card.

When doing a lot of parts swapping and testing in a vintage Mac (like my SE/30), the human brain can get so focused on doing things quickly it forgets the basics like never plugging in an accelerator PDS card into the top connector of the TS Adapter.  It's a blunder just waiting to happen to anyone, not just those of us with the name "James W." 

Totally agree! I was rebuilding an SE/30 from scratch and then troubleshooting some memory that I wasn't too sure was reliable so I'd pulled the motherboard countless times in one evening. It's a shame the stakes are so high when working with old and rather rare bits and bobs...

 

[Bolle]

Your Twinspark is still working fine, the Turbo040 however is shot.

I do get instant death chimes when turning on the IIci with it plugged in.

When measuring resistance to ground on the pin that got hit by 12V on the ASIC I get around 1k while on mine this is somewhere in the megaohms.

Even on some surrounding pins the resistance to ground is very low while on mine they are not. This indicates that something inside the chip shorted out.

Getting a replacement is going to be near impossible... some of those wonky chinese chip-trading-reseller-whatever sites say they stock a small amount of those.

@JDW care to send them an inquiry and see if they actually stock them? Chances are they are fakes, but that would be a weird part to fake as probably nobody ever is going to need one of those ever, except you :tongue:

Part number for the chip is VY14676 and a google search will turn up two sellers.

Not sure if I am brave enough to swap in my ASIC just for testing :/

 

[joethezombie]

I put out some requests for VY14676-2 from some US sellers about a year ago.  Out of several, two responded, but both required $50 minimum order.  I am super curious if they are legit.

 

[Bolle]

$50 minimum order

Most important question: how many chips would you get for $50?

 

[joethezombie]

Hi Joe,

 

 

Parts are new and stock, DAYSTAR/1994

 

10 pcs @ $5.00 per to hit our $50.00 min

It was 50-50 to take the chance, but in the end, I passed.

 

[Bolle]

Hm, might be different if we split the risk?

Let‘s see what @JDW says. I’d throw in some cash as well for a few chips.

 

[JDW]

Hm, might be different if we split the risk?

Let‘s see what @JDW says. I’d throw in some cash as well for a few chips.

If that reply to @joethezombie was 1 year ago, another reply back to them should be sent to confirm they still have them.  I would also suggest asking them how they managed to get their hands on so many "Daystar" chips, if indeed they really are official Daystar chips.  If they claim they are indeed Daystar chips, then they should be able to answer the question, "how were they used."  If they reply "accelerator cards," then perhaps the chips are legit. 

I've bought version-C 68030 CPUs from China before with success, but VLSI chips specific to a smaller manufacturer like Daystar is something altogether different, so we have to be careful here and do our best to confirm they are indeed what we need.

The chip we are talking about is the big one show in my photo here:

View attachment 25620

If indeed that VLSI chip is bad and if replacing that one chip would fix the card, assuming the Chinese chips are legit, it's worth buying them to replace the chip, especially since @james_w would need one too, seeing he did exactly the same thing I did.  This is assuming he has the same 040 card that I do, shown in the photo above.

 

[Bolle]

especially since @james_w would need one too, seeing he did exactly the same thing I did.

He however has the older Turbo 040 revision that does not have the ASIC but a lot of GALs instead. Totally different story.

There are going to be at least one (maybe more) dead GALs on there.

However keeping a few of those ICs around if they are legit might still be a good thing just in case.