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JDW

Modern PSU for the SE/30

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/PFW does nothing.  It's just always high.  Must of been in Oregon too long.  It would be just a straight through connection to the THRU slot on the ProtoCache, and doesn't exist on the CACHE slot.

 

DCaDftMF states:

Quote

*On the Macintosh SE/30, this signal name has been referred to as PWROFF, but its function is the same on both theMacintosh IIsi and the Macintosh SE/30.

 

But this is a lie.  It serves no function on the SE/30.  (I hooked up my logic analyzer to the C1 pin, and it never changes until one flicks the power switch to off)

Edited by joethezombie

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Did you try grounding the line to see what happens when it goes low? I wonder how it's implemented in the IIsi now. I'll take a look at the three available schematics and docs, maybe I can come up with something crazy. :blink:

 

Offhand, hacking the system shutdown command so it triggers an ADB powerdown event would sidestep the immovable /PFW signal issue. Blipping the switch in the ATX PSU circuit via that generated ADB event would mimic the KBD power key from the Mac side in place of displaying the "it's safe to power down you macintosh" dialog box.. Coupling that kluge with the Power Key event on the other side via an internal ADB signal tap comes to mind. Might need to use diodes or logic to decouple the two ADB event signals of the synthesized soft power down from the Mac dialog side and soft power up from the KBD. That would get around the lack of the "are you sure you want to power down or just restart" dialog from the KBD event. This approach isn't at all kosher, but might it be just good enough if it could be pulled off?

Edited by Trash80toHP_Mini

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So here's a build log, perhaps this will help others wishing to do the same:

 

First thing I did was take the and remove internals of the FSP220 from the casing.  I unscrewed the ground lug and desoldered the leads from the power connector (there is no power switch on this model).  Don’t mix up the neutral and hot leads, definately mark them somehow.  Here it is inside the empty Astec casing for fitment trials:

IMG_0426.thumb.jpg.5a9c8e535b6438b4ee0b71221b611790.jpg

 

Yay, it fits!  So now lets make a method to screw the PCB to the case.  Firstly, bend down the center standoff and make it flat with the case because we wont be using it.  Then, use standard PC motherboard standoffs, drilled and screwed into the casing with the same hole pattern as the FSP220 PCB.  Make sure to leave the clear insulation sheet in place:

IMG_2030.thumb.jpg.88642985d12867dfa9af828d4f92a393.jpg

 

Here is the backside of the casing, showing the PC motherboard standoffs drilled through.  The depth was shallow compared to the casings normal standoffs, so there is no clearance issues with stabbing the analog board:

IMG_2036.thumb.jpg.76bd164b0b689c98e787ae22d7d868fc.jpg

 

On the original Astec power supply, the PCB and the power switch are connected with a cable.  I got the idea to desolder the connector from the old PCB and use it to make a similar plug in cable.  First, solder a white (neutral) and a black (power) appropriately  gauged wire to the bare leads on the FSP220. (Remember we had desoldered them from the power connector earlier, and didn’t mix them up).  After soldering, secure and insulate them with heat-shrink.  Now take the other ends of the wire, and attach them to the that desoldered power connector, and insulate them with heat-shrink.  The green (ground) wire, I was going to attach to the empty pin, but the original power connector is missing the matching terminal inside.  I was going find one to order, but in the end just soldered it directly to the ground lead on the power connector.

IMG_2034.thumb.jpg.3a9b2f34c0f06dc7580971f454820240.jpg

 

Normally, this style of power supply is operated by soft-power.  A momentary switch on the computer case issues a latch which the motherboard places on the PS-ON pin of the power supply.  Our SE/30 does not have the circuitry to do this, so we need to force the power supply to be on when the switch is on.  We do this by shorting the PS-ON pin (green wire) to GND (black wire).  After placing the small shunt, the power supply will turn on fully as soon as the power switch is flipped on.  You can secure the shunt with a dab of hot glue.  Also in this picture you see the connector with red, brown, and orange wires.  I left this intact for a couple of reasons which I will explain in just a bit.

IMG_2032.thumb.jpg.3827923d84c0eda55e9876ac7b033e56.jpg

 

Now we need take the ATX connector from the FSP220 and remove the terminals corresponding to our power requirements.  They make a special terminal removal tool, or you can cheap out and use your wife’s flat sewing machine needle.  I used yellow/black for the 12v Sweep, yellow for the 12v Drive, blue is -12v, red is 5v, and blacks are ground.  Take the old SE-SE/30 connector from the old PSU and remove all the terminals so it is empty.  Now because ATX and the SE-SE/30 connector use the same housing, we can directly place the terminals from the ATX connector into the correct ports.  I also left a Molex and floppy style connector attached for SCSI2SD power:

IMG_0442.thumb.jpg.da0c2ce96ce529ec6a9c18761038be77.jpg

 

Looking at the above picture, everything to the left that’s in the bread tie needs to be removed.  The best way to do this is by color.  Take everything yellow that you don’t want, and clip them off.  Then place some heat-shrink around the bundle of yellow, and fill the top with hot glue.  Proceed to the next color.  By keeping the colors together, you remove any risk of shorting:

IMG_2035.thumb.jpg.f11133581c28fd0fc342962b27e37bcd.jpg

 

So why didn’t I just recap the existing PCB?  It was ruined due to capacitor leakage:

IMG_0427.thumb.jpg.61e9ad98d6f2d3ba055f9fc1935d8ce3.jpg

 

 

Afterthoughts, notes for next time:

 

Now that I have a nice terminal crimper, I wouldn’t have removed the terminals from the ATX connector.  I would have just lopped it off and put new terminals on the wires I needed.  Then, I could have had a shorter cable going from the power supply to the analog board.  It’s too long for my liking, but not unwieldy .

 

I wouldn’t make the little cable to attach the power switch to the PCB.  I’d just solder the power leads directly to the switch.

 

I left the fan installed for a short while, but ended up clipping it completely out.  Don't forget to insulate the ends of the wire after clipping it out.

 

I did this back in December of 2016, and I haven't had a single issue.

 

 

Edited by joethezombie

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1 hour ago, joethezombie said:

So here's a build log, perhaps this will help others wishing to do the same...

Superbly written and photographed, Joe!  A thousand thanks for your time in doing this.

 

QUESTION No.1: Regarding your "bread tie" bundle of wires, you suggest cutting them off but then you say to use heat shrink and hot glue.  I'm not clear on your intentions here.  If you don't need wires and potentially won't ever, why not cut them off right at the PCB so there is no chance of shorting and you eliminate all of the wire entire, which means no hot glue or heat shrink would be needed on them at all.  Can you explain?

 

QUESTION No.2: What drill bit size did you use to cut those 4 holes in the stock metal PSU case?  Since you purchase standards that are "just the right length" and since you are expecting the screw side to keep the new PSU well mounted for years, having the right drill hole size is very important.  (Normally, it would be best to use a longer screw and the apply a nut on the back side, but there is no clearance for the nut, which is why you did what you did.  I might put some superglue on there to absolutely ensure vibrations don't cause the screws to loosen over time.)

 

QUESTION No.3: Have you used your SE/30 continuously for more than an hour and then felt the PSU (outside of the stock metal enclosure in which the new power supply is housed) to see how warm it gets relative to the stock PSU?  No doubt the new one runs cooler.  I'm just curious.

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Answer 1:  The reason I used heat-shrink and hot glue, is because the huge mass of wires make it very difficult to cut off right at the PCB, especially if the removal target is in the middle of the bundle.  It's not as easy as you would think to spread wires and clip at the base with so many in such a small area.   Plus, there is the vertical PCB right next to the wire bundle that makes it very difficult to fit in the nippers.  I didn't want any chance for different voltage wires to be able to short together.  Desoldering can work, but the underside of the PCB is a mess, and if you are not careful, you could definitely cause problems.  If you are able to clip off right at the PCB, do it!  Just don't leave a stub that the insulation could slip off and cause the bare wire to short against the PCB.  There are many voltages in a very small space.

 

Answer 2: I used a "stepper drill bit" to make the hole larger and larger until the motherboard standoffs self-tapped into the holes.  I did this because I didn't know the size of the standoffs I had on hand.  If you purchased some, they would probably have a specification for proper hole/tap size.   One of the holes I made too big by mistake, but you can use a dab of solder or epoxy to permanently attach the standoff to the casing.

 

Answer 3: After snipping the fan, I was a bit worried about over heating.  I ran Apple Personal Diagnostics in loop mode all day long.  The casing to the power supply becomes warm, but not as warm as the flyback shielding, and certainly not anywhere near hot.   Coincidentally enough, I just ordered a laser thermometer because I wanted to test the temperature of a Radius Rocket on which I replaced the CPU, so if you give me a week or so, I can take comparison tests with my other SE/30 which houses a recapped Sony PSU.

 

 

 

Edited by joethezombie

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Thank you Joe for posting this.  Very comprehensive.  I have a couple of follow-up questions:

 

1. Did you remove the fan due to the noise, or were there other considerations as to why you removed it?

2. Although this will be apparent when I take my power supply apart:  I would assume the switch just switches the line?  From the description above, it seems like both the line and load leads are connected to the cable that attaches to the power switch.

3. With all of the prior discussion about the importance of an isolated 12V for the Sweep, have you noticed any display issues?  After doing some reading, it seems like a lot of these power supplies don't actually have separate rails so I wasn't sure if things like disk access might cause some noise.  I guess the SCSI2SD is just 5V so it wouldn't matter, but I'm thinking the floppy would use 12V.

 

Thanks again!!!

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1.  Yes, I removed the fan only due to noise.  There is no other reason to remove it.  If you are fine with noise, go ahead a leave it in.  Like JDW, I absolutely hate the sound of a fan.  I replaced the fans in all my compacts with a silent model as well.

 

2.  If you look at the 2nd picture of the empty power supply case, you will see that it is a DPST switch, so both the line and load is switched.

 

3.  There is no display issues, even while floppy drive access.  The FSP220 is advertised as having two isolated 12V rails (one is marked yellow with a black stripe, the other is solid yellow).   Also:

Quote

I had previously (in that other thread that is now gone) dissected an original Sony PSU for the SE-SE/30 and found the only "isolation" between the 12V Sweep and the Drive outputs were a single diode and filter capacitor.  

So if you are concerned with "Apple approved isolation", simply add a diode and a filter capacitor to the yellow/black wire.  But I find it is not needed.  I can only imagine power supplies have improved just a little over the past 30 years.  It would be an interesting experiment to throw the scope on each and see what the differences are.

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3 hours ago, joethezombie said:

Answer 3: ...if you give me a week or so, I can take comparison tests with my other SE/30 which houses a recapped Sony PSU.

I look forward to it. Thank you!

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On 5/5/2018 at 3:15 PM, joethezombie said:

So here's a build log, perhaps this will help others wishing to do the same:

 

Now that I have a nice terminal crimper, I wouldn’t have removed the terminals from the ATX connector.

 

 

Nice explanation.    Thank you!

 

Which terminal crimper did you choose?  Did you try more than one?   I'm in the market for one, but there's a dizzying array.  I should probably consult with the hardware guys in the lab upstairs at work...   But they have a little different focus than us hobbyist users.

 

Are you quoting yourself or someone else about dissecting the Sony PSU and finding just a single isolation diode on the 12V rail?

 

The reason I ask is that I wonder if the rail was 12V before the diode or 12V after the diode.    Vf is going to cut .7V - 1.3V off of the voltage.    If the rail must be 12V after the diode, that's inconvenient.   If the sweep will tolerate the loss, then I see no reason not to add a diode on the wire to the sweep.    Covering the amperage will be  a little challenging.   Was it close to 3A?

Edited by trag

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26 minutes ago, trag said:

Which terminal crimper did you choose?  Did you try more than one?   I'm in the market for one, but there's a dizzying array. 

But even if you have a terminal crimper, you would also need to buy appropriately sized terminals that would be an exact fit for the plastic connector you intend to use.

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28 minutes ago, trag said:

...I wonder if the rail was 12V before the diode or 12V after the diode.    Vf is going to cut .7V - 1.3V off of the voltage.    If the rail must be 12V after the diode, that's inconvenient.   If the sweep will tolerate the loss, then I see no reason not to add a diode on the wire to the sweep.    Covering the amperage will be  a little challenging.   Was it close to 3A?

When considering the ASTEC version of the SE/30 PSU and the 1.25A SWEEP output, there's actually more to it than a single diode.  The single diode being talked about is likely D14, but as you can see below, that diode merely links the SWEEP output to the +12V 2.1A output.  I've not had time to do a complete analysis of the entire circuit, but when examining the output portion, it certainly looks like high-going voltage spikes from the +12V 2.1A output are being clamped to the SWEEP line via D14.

 

AstecPSU-outputs.png

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1 hour ago, trag said:

Which terminal crimper did you choose?  Did you try more than one?

I bought one just like this from ebay.  I haven't yet used it enough to really give an opinion.  I've crimped some small terminals for an ADB project using digikey WM14852 and WM4561CT-ND, and that's about it, but they did a very neat, professional looking, and (more importantly) well-working job.

 

1 hour ago, JDW said:

But even if you have a terminal crimper, you would also need to buy appropriately sized terminals

Right, but most of the molex terminals are "universal" per se, as the ones from the FSP220 fit and locked into the old SE-SE/30 connector without issue.  The same (a guess, I didn't buy one) connector can be found at digikey with WM3704-ND, which also lists compatible terminals.

 

1 hour ago, trag said:

Are you quoting yourself or someone else about dissecting the Sony PSU and finding just a single isolation diode on the 12V rail?

"Dissecting" is definitely much to strong a word.  I should also clarify it wasn't Sony, rather Astec, as referenced in the photos.  While musing around looking for a modern replacement, I was curious why I couldn't just use a single 12V supply, so I started sketching out the circuit from the outputs working back to spot the differences.   Keep in mind, this was on a non-working unit, so I have no voltage measurements.  Anyway, this turned out to be a partial effort-- after finding the FSP220 with two 12V rails, I just went with that and never went back to complete/verify.  Apologies my quickly typed sentence had such a strong inference.

 

58 minutes ago, JDW said:

When considering the ASTEC version of the SE/30 PSU and the 1.25A SWEEP output, there's actually more to it than a single diode.

Thanks for posting, I remember having a difficult time trying to find the schematics when I searched.  I see the complete schematics have now been linked recently.

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4 hours ago, JDW said:

But even if you have a terminal crimper, you would also need to buy appropriately sized terminals that would be an exact fit for the plastic connector you intend to use.

 

They're usually Molex connector housings, and once one identifies them on Digi-Key, the product page will yield links to compatible pins and mating housings.   So finding the right pins is not usually a problem.   Plus, all the Mini-fit Jr. housings use the same pins, and every power cable connector I've seen so far (at last the two row ones) are Molex Mini-fit Jr. line.    It could be a problem for some connectors, but I haven't run into a problematical one yet.    Of course, I haven't been doing much of that kind of running the last 10 years.

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With regard to crimping, isn't it more trouble than it's worth?  You need to buy the correct crimper tool, then buy the correct terminals, then make sure you have the means to remove the terminals from your existing connector.  And if like me you live outside the US and decide to buy all that from the US, you have international shipping charges with which to contend.

 

Wouldn't it just be easier to cut off all the wires from a connector on your new PSU, then slip on some heat-shrink tubing on each wire, then cut off the stock SE/30 connector but leave 10cm or so of wire length dangling, then solder the appropriate wires together, then slide over the heatshirink tubing and shrink it?  Wire insulation colors will be different, but Steve Jobs won't be looking, so it's okay! :-)

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1 hour ago, JDW said:

Steve Jobs won't be looking, so it's okay! :-)

What? He's *always* looking, as he is omnipotent now :lol:

 

c

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10 hours ago, JDW said:

Wouldn't it just be easier to cut off all the wires from a connector on your new PSU, then slip on some heat-shrink tubing on each wire, then cut off the stock SE/30 connector but leave 10cm or so of wire length dangling, then solder the appropriate wires together, then slide over the heatshirink tubing and shrink it?  Wire insulation colors will be different, but Steve Jobs won't be looking, so it's okay! :-)

 

Not satisfactory to my OCD impulses.    Plus, with practice, crimping the pins isn't that difficult.   Crimpers are (or can be) more or less universal.  They have different imprints for different diameter "legs".   So getting the right one isn't really an issue.   It's more a matter of there being a myriad of crimping tools, with varying degrees of comfort and convenience.

 

I find it easier to just buy new housings rather than try to salvage old housing by removing the pins.  They're not pricey.

 

Being outside the USA puts a different dimension on it though.

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I was finally able to finish this mod.  I ended up ordering two different power supplies and ended up starting with the easier one to retrofit first.

 

This time, I used a Seasonic SSP-250SUB.  This supply serves up the right power mix and has the added benefit of being modular so that you don't have the rats nest of wires coming out of the supply, but instead a 26 pin molex connector.  When I took it apart, the added benefit was that the power plug wasn't soldered in like on the other supply I bought and instead just had to be unplugged from the power board and slipped through the back of the supply on disassembly.

 

I took out all of the pins from the 26 pin molex connector and just re-wired back in the pins I needed.  I bought a crimpling tool and some 10 pin molex plugs to match up with the SE/30's analog board plug.  I ended up wiring the power switch on the SE/30 to the Power On/Ground rather than switching the power from the wall.  I used brass standoffs to mount power supply PCB, similar to what was done above.

 

I'm not sure if there is any independance between the "two" 12V rails (There was no resistance between any of the 12V wires) but I sent +12V from the main motherboard connector to one 12V pin on the SE/30 connector and the other 12V from a 4 pin motherboard connector to the other 12V pin on the SE/30.

 

I tested the power supply with a couple of hard drives before placing into the Mac and then removed the hard disk molex cables from the power supply before finalizing.  System booted up the first time and voltages seem rock solid when tested through the floppy port (whether hard disk / floppy etc. are being accessed).  I still need to recap the analog board.  The system is brighter than it was (still not as bring as it should be) and there is some ghosting of the images where there are window title bars or when menus are pulled down.

 

 

IMG_2885.thumb.jpg.a871f00abed01951acc79ede3c38cf6c.jpgIMG_2886.thumb.jpg.762106e4d842fa506845d35dc555a8ab.jpgIMG_2890.thumb.jpg.1d3d1aaf6b60b968893b52edab1c9cc7.jpgIMG_2898.thumb.jpg.d8cdec67005de819ec21ae0b5514045d.jpgIMG_2899.thumb.jpg.e385a3bcf565cc3a1671b35804c1fdc4.jpgIMG_2902.thumb.JPG.c6a8d24d2e8103583d128ffda71418ac.JPG

IMG_2896.jpg

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Most excellent! That vented side panel is pretty interesting, mine (SE/30 & SE) have solid side panels thermal pasted atop the heatsinks in the PSU. Who made that particular PSU and are they common?

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Interesting.  The Seasonic is an “industrial” power supply.  Specs are clearly more than adequate in terms of current capability which makes me wonder about that cause of the ghosting.  I assume you did not have any ghosting with your old power supply?

 

joethezombie, do you have any ghosting with your new power supply? 

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33 minutes ago, JDW said:

Interesting.  The Seasonic is an “industrial” power supply.  Specs are clearly more than adequate in terms of current capability which makes me wonder about that cause of the ghosting.  I assume you did not have any ghosting with your old power supply?

 

joethezombie, do you have any ghosting with your new power supply? 

I did have ghosting before. Based on some research I did I think it's the CRT. I did this mod on this SE/30 rather than my good SE/30 with a perfect screen just in case it started on fire. :)  The screen is brighter than before though. 

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56 minutes ago, Trash80toHP_Mini said:

Most excellent! That vented side panel is pretty interesting, mine (SE/30 & SE) have solid side panels thermal pasted atop the heatsinks in the PSU. Who made that particular PSU and are they common?

It's an Astec. My other SE/30 to be worked on next is a Sony PSU. 

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On 5/19/2018 at 1:44 PM, superjer2000 said:

I was finally able to finish this mod.  I ended up ordering two different power supplies and ended up starting with the easier one to retrofit first.

 

This time, I used a Seasonic SSP-250SUB.  This supply serves up the right power mix and has the added benefit of being modular so that you don't have the rats nest of wires coming out of the supply, but instead a 26 pin molex connector.  When I took it apart, the added benefit was that the power plug wasn't soldered in like on the other supply I bought and instead just had to be unplugged from the power board and slipped through the back of the supply on disassembly.

 

I took out all of the pins from the 26 pin molex connector and just re-wired back in the pins I needed.  I bought a crimpling tool and some 10 pin molex plugs to match up with the SE/30's analog board plug.  I ended up wiring the power switch on the SE/30 to the Power On/Ground rather than switching the power from the wall.  I used brass standoffs to mount power supply PCB, similar to what was done above.

 

I'm not sure if there is any independance between the "two" 12V rails (There was no resistance between any of the 12V wires) but I sent +12V from the main motherboard connector to one 12V pin on the SE/30 connector and the other 12V from a 4 pin motherboard connector to the other 12V pin on the SE/30.

 

I tested the power supply with a couple of hard drives before placing into the Mac and then removed the hard disk molex cables from the power supply before finalizing.  System booted up the first time and voltages seem rock solid when tested through the floppy port (whether hard disk / floppy etc. are being accessed).  I still need to recap the analog board.  The system is brighter than it was (still not as bring as it should be) and there is some ghosting of the images where there are window title bars or when menus are pulled down.

 

 

IMG_2896.jpg

OK, I am in.  I just ordered one of these from NewEgg.com for just under $50 shipped to deal with my leaky PSU. It will arrive early next week and this should be a fun project.

 

Does anyone have a diagram that maps the colored wires from the original PSU to their needed voltages?

 

Here is what I have:

BK, BK, BK OR, YW

BR, BK, BK OR, RD

 

THx!

 

 

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