I fried the ADB controller of a SE/30

[ironborn65]

This is a very sad post that will show my dumbness, I really would like to be anonymous now.

I was assembling my lovely SE/30 adding the Bolle's GreyCake card on top of the Carrera040 and the Ethernet card.
It was all fine, until the last reboot before closing the case, when I did the dumbest of all things (please don't ask) ... long story short, the ADB ports are non-functioning anymore and the +5V is not present in the connector, so it boots just fine but not no ADB device is working, of course ... there is no +5V anymore.
I very very very likely fried the UL11 ADB controller (the EGRET maybe) I can not express my depression mixed with barely controlled anger.
I'm tempted to sell all my collection and forget about retro-computing!

As the last resource, I'm begging here for the help of a member or a specialized shop who is willing to fix it, likely by replacing the UL11. Of course, I'll pay any fee required. In the past I did SMD soldering and chip replacement but at this time I'm scared about doing anything.

I'm based in Europe, so continental EU is preferred, but I can escalate to the USA or Australia to repair this LB.

Please be kind, depression is lurking

 

[Daniël]

Before panicking, have you checked fuse F1 on the logic board? It's behind the ADB ports, and is responsible for the 5V rail on the ADB ports. It may be all that's wrong here.

 

[croissantking]

Don’t worry, I accidentally destroyed an SE/30 GLUE chip the other month which is really expensive to obtain, but I’m not being too hard on myself. The ADB chip actually has been cloned/reverse engineered, so you could fabricate a replacement.

But yes, check the fuse first.

 

[robin-fo]

Without checking the schematics, I‘d be surprised if you loose 5V by frying the ADB controller…

please don't ask

I‘m so curious . Maybe you can help others to prevent a similar issue?

 

[ironborn65]

Hi mates for the suggestion @Daniël. I took courage and I tested the F1 fuse.
Indeed there is no continuity.
Can I just temporarily bypass it for testing purposes and later replace it with a new one?

thanks @croissantking for putting it in the right perspective... I'm too hard on myself

 

[croissantking]

Hi mates for the suggestion @Daniël. I took courage and I tested the F1 fuse.
Indeed there is no continuity.
Can I just temporarily bypass it for testing purposes and later replace it with a new one?

thanks @croissantking for putting it in the right perspective... I'm too hard on myself

That’s great news, maybe all that needs replacing is a cheap fuse.

I’m tempted to say it would be ok to bridge it for testing purposes, but maybe see what others say as well.

 

[falen5]

Go on ... Tell us how you blew it - we have all been there

I fully restored a 110 volt 128k here in Ireland. I put on the back cover for the last time and plugged it in one more time before putting it back in storage ............ and accidently plugged in a 240 volt lead instead of my 110 v lead .......... BANG !!!!........ the joys of it !!

 

[ironborn65]

... ok, take the popcorn, the soda, and enjoy the movie
-----------------------------------------------------
Once upon a time, there was an excited guy who wanted to assemble the 3rd Boole's card in his most loved SE/30.
But he wanted to monitor the +5V rail. to see if the PSU was performing fine and he decided to insert a pin in the ADB port.
The only thin and long enough wire the smart guy had at hand was the long wire of a ... capacitor.

He left one end open and connected the multimeter on the same side that was inserted in the connector, in this case, it was being used just like a wire. He knew he was playing with the fire but he kept going ... the smart guy could have done it in millions of different ways.

With both Carrera040 and Ethernet card, it was +4,87V.
he tested in the same way with only the GrayCake card, it was +4,97V.
He said, he could later tune the voltage but it was all good to go.

Excited about the new toy, he assembled all the 3 cards and re-inserted the wire to monitor the +5vV rail once again ... but this time on the wrong side ... he got +0,7V.
So, the brain-disconnected guy decided to remove and flip the capacitor ... he realized too late what he did

End of a sad story.
-----------------------------------------------------

@falen5 thanks for sharing... Ireland, I've been living in Ireland for 2 years

 

[cheesestraws]

Some brave people take the fuse out entirely and leave it like that. I wouldn't do that personally, but temporarily you're OK to bridge it. What happened here was the fuse doing its job: it prevented any further damage upstream of itself. So I'd replace it.

(Also, we all do things like that. I once attempted to discharge the filter capacitors of a power supply that was still plugged in. Oops. Big spark and reset of circuit breaker later, time to do repairs...)

 

[joshc]

(the EGRET maybe)

Egret came later (LC I think), there is no Egret on an SE/30.

 

[falen5]

... ok, take the popcorn, the soda, and enjoy the movie
-----------------------------------------------------
Once upon a time, there was an excited guy who wanted to assemble the 3rd Boole's card in his most loved SE/30.
But he wanted to monitor the +5V rail. to see if the PSU was performing fine and he decided to insert a pin in the ADB port.
The only thin and long enough wire the smart guy had at hand was the long wire of a ... capacitor.

He left one end open and connected the multimeter on the same side that was inserted in the connector, in this case, it was being used just like a wire. He knew he was playing with the fire but he kept going ... the smart guy could have done it in millions of different ways.

With both Carrera040 and Ethernet card, it was +4,87V.
he tested in the same way with only the GrayCake card, it was +4,97V.
He said, he could later tune the voltage but it was all good to go.

Excited about the new toy, he assembled all the 3 cards and re-inserted the wire to monitor the +5vV rail once again ... but this time on the wrong side ... he got +0,7V.
So, the brain-disconnected guy decided to remove and flip the capacitor ... he realized too late what he did

End of a sad story.
-----------------------------------------------------

@falen5 thanks for sharing... Ireland, I've been living in Ireland for 2 years

That is a good one , no doubt about it

And I know what it is like - you feel like throwing yourself out a window when this kind of stuff happens

But there is a bright side - when the anger EVENTUALY subsides you get to fix the mistake and then the machine finally springs back to life

Hopefully its just a blown fuse and all will be good

 

[jmacz]

I am guilty of so many of these types of brain dead moves, join the club

Hope it’s just the fuse, I believe it’s meant to protect against just this type of mistake.

 

[croissantking]

decided to remove and flip the capacitor ... he realized too late what he did

I don’t understand how that blew the fuse?

 

[ironborn65]

the opposite side of the capacitor had a -5V charge when I removed it
when it was inserted on that side there was a 10V difference and a surge of charge passed through the fuse, inside->out

this is what I thought, does it make sense?

 

[croissantking]

the opposite side of the capacitor had a -5V charge when I removed it
when it was inserted on that side there was a 10V difference and a surge of charge passed through the fuse, inside->out

this is what I thought, does it make sense?

Ah, as in the capacitor was charged up and then discharged into the port.

That’s quite funny! I can see why you would have missed that, because you weren’t really thinking of it as a capacitor at that moment; rather, a miscellaneous device with useful leads on either end.

 

[cheesestraws]

Yeah you really don't have to be too embarrassed about that, I can totally see myself doing the same thing.

 

[ironborn65]

thanks you *all* guys!!
My beloved Mac SE/30 is working, what a relief!!! I could not think clearly ... and I was not aware of the fuse with the form factor of a resistor.

It's a great community, thank thanks again.

And since you might be curious, here is the beast (Carrera040 + cache + GreyCake + Ethernet + 32MB RAM) ... ROM is still the stock one, I'm not able to fit it in properly despite springs, elastic bands, 3d printer supports ... I should replace the ROM connector.

 

[AndyMc1280]

Go on ... Tell us how you blew it - we have all been there

I fully restored a 110 volt 128k here in Ireland. I put on the back cover for the last time and plugged it in one more time before putting it back in storage ............ and accidently plugged in a 240 volt lead instead of my 110 v lead .......... BANG !!!!........ the joys of it !!

Ouch

The SE30 you've done for me was originally 110v. There's a story there which I forgot but yours has just reminded me. I was with brother when he'd just unpacked his shipping containers coming home to Scotland from USA in about 1990 and was showing me some stuff. My ten year old self got a rather large fright when he accidentally kicked his US powerstrip which was plugged into a transformer, loud bang and sparks from the power strip, mac cut off and couldn't be powered on. Much swearing and me in tears.

Not sure if anything damaged but I do know he went back to Apple In Ireland and a UK spec PSU was installed at cost. The machine was new/current at the time

 

[Arbee]

Great that your machine works again! For the record, SE/30 isn't Egret, it uses a PIC1654S. You can replace that with a more modern PIC and Tashtari's translation of the original PIC code.