Video: Recapping the SONY CR-44 Power Supply (for SE & SE/30)

[JDW]

I finally finished my video on recapping the SONY CR-44 PSU, which can be used in the SE and SE/30.  The video is long but informative.  A Mouser Cart is linked in the text description under the video (you'll have to watch it on YouTube to see that), for those of you wanting to easily purchase all the electrolytic capacitors required.  You also find a link in that description to my SEASONIC PSU replacement video, for those of you who haven't seen that one either.  There's still reason to recap the SONY PSU though -- it's fanless and dead silent when operating.  If you have only 1 PDS card and no major upgrades, the SONY PSU, once recapped, is more than adequate.  Enjoy.

 

[joshc]

@JDW Thank you so much for taking the time to make this video, I appreciate this must have taken a lot of your time.

I was struggling to find a replacement for the original 620 uF 400V capacitor for C162 but after watching your video I've found a United Chemi Con 680 uF 400V which should be fine, I hadn't originally realised that using higher capacitance was OK until I watched your video!

 

[Oberlehrer]

I have watched so far just the first 3 minutes. Is it accepted/veryfied knowledge that the Sony has a black switch and power connector and the Astec a white one? I'm asking because I'm having two SE/30's with Sonys and one has black components and the other one whites...

 

[JDW]

I was struggling to find a replacement for the original 620 uF 400V capacitor for C162 but after watching your video I've found a United Chemi Con 680 uF 400V which should be fine, I hadn't originally realised that using higher capacitance was OK until I watched your video!

That 680µF 400V capacitor is listed in the Mouser Cart that I always put in the Text Description beneath every one of my videos.  I would encourage everyone to always check the Text Description because it contains far more than just that.  I actually spend days crafting the Text Description alone to ensure not only that all information is 100% accurate, but that I feel satisfied that the information presented is sufficient to help people accomplish what is set forth in my videos.  The only downside to providing a Cart is the Mouser is always putting at least one item in the cart on backorder.  But if you search Mouser for the same voltage and capacitance and take note of the physical size of the caps in my Cart to ensure your replacement (for the backordered items) is the roughly the same, you'll be fine.

I have watched so far just the first 3 minutes. Is it accepted/veryfied knowledge that the Sony has a black switch and power connector and the Astec a white one? I'm asking because I'm having two SE/30's with Sonys and one has black components and the other one whites...

It's not only the color of the power switch that differs.  The vent holes in the side of the PSU also indicate different models.  In my experience, the SONY PSUs do have the Black power switch.  I've yet to see a white one on a SONY, but that isn't a 100% guarantee that there were never any.  In the world of sourcing electronic components, you never know!

 

[Oberlehrer]

In my experience, the SONY PSUs do have the Black power switch.  I've yet to see a white one on a SONY, but that isn't a 100% guarantee that there were never any.

 

[JDW]

Which is why I said, "In the world of sourcing electronic components, you never know!"  SONY might have wanted black parts but were only able to secure white at some point, or maybe white was cheaper at one point in time.  But as you can see, there are no heat vents on the side of the SONY PSU.  But on ASTEC PSUs, there are heat vents there.

 

[Rjp663]

JDW,

I'm getting ready to re-cap a CR-44 power supply I purchased on eBay. Prior to re-capping I wanted to bench check output voltages. The 5vdc output is fine; however the 12vdc is reading 13.9vdc and -12vdc reads -9vdc.  

Question: Can the +/-12vdc outputs be read if the power supply is unloaded?

Thank you

Rick

 

[JDW]

@Rjp663

No-load voltage measurements will show oddball numbers like that.  It's not necessary to test in the loaded condition prior to recap, but if you have a batch of resistors and want to see how the voltages change under load, just put a 1/4W or larger 1kΩ resistor between the individual voltage outputs and Ground, then measure at the voltage output.  That's a very tiny load, so the voltages may not vary too much.  A much better test would be 100Ω, but you will need a 2W (or larger) rated resistor in that case, but it would give a better idea of what the power supply will be like under a small but reasonable load.  As you go down in resistance though, you will need higher wattage ratings, such as a 5W for 47Ω and so on, otherwise you will burn your resistor during testing.  

You can also put resistors in parallel to gain a higher overall wattage rating, but you will need to do math to ensure you know what the end resistance will be.  For example, five 470Ω 1/2W resistors in parallel yields a 94Ω resistor rated for 2.5W.

Resistors in Parallel Calculator

Ohm's Law Calculator (Plug in 12V and then a Resistance value, and the click Calculate.)

 

[Rjp663]

JDW,

Thank you for the detailed technical reply. I’m going to proceed with the re-capping project. If I have problems afterwards, I explore making a dummy load as you suggest. Thanks again.

Rick

 

[JDW]

@Rjp663

Recapping is the easiest thing to do because you can then connect up everything and check voltages at the external floppy disk connector.  I would advise checking the no-load voltages first after you recap, just to make sure all seems reasonably well, and then after that connect everything on your Mac.  If you then measure voltages at the floppy disk connector and get something much lower than expected on the 5V line, the culprit is most definitely the main wire harness that connects the Analog Board to the Motherboard.  It could be corroded contacts or even a badly aging wire.  I've seen that before on my SE/30's.  Swapping out the harness or fixing the wires usually gets the 5V line very close to 5V again.

 

[Rjp663]

JDW,

I followed your CR44 recapping video to refurbish my power supply. Easy day! Thank you for producing the video, it was very helpful.

Rick

 

[JDW]

Thank you for sharing your recapping success story, @Rjp663!  That's great to hear!

 

[keropi6k6]

excellent video - I wish I knew about it before I recap my PSU , would have spared me the time to search for caps on mouser  :b&w:

 

[JDW]

excellent video - I wish I knew about it before I recap my PSU , would have spared me the time to search for caps on mouser  :b&w:

Thank you. I put Mouser Carts in the text description of all my videos.  

I also try to post links to my videos here and in other places where vintage Mac users get together and chat, but  there are still a lot of folks who haven't found those videos.  For the sake of curiosity, did you search this forum or Youtube before you did your recap and just not find my video?  If so, I've love to hear the keywords you used in your search.  Maybe I need to change the tags so folks can find it easier.

 

[keropi6k6]

Thank you. I put Mouser Carts in the text description of all my videos.  

I also try to post links to my videos here and in other places where vintage Mac users get together and chat, but  there are still a lot of folks who haven't found those videos.  For the sake of curiosity, did you search this forum or Youtube before you did your recap and just not find my video?  If so, I've love to hear the keywords you used in your search.  Maybe I need to change the tags so folks can find it easier.

I did not search at all for the PSU recap, I just removed the old caps, determined what series they were and just ordered replacements from mouser paying attention to the dimensions. 

Pretty much I did the same for the analog board.

When I searched google for the logic board I found your thread and the other one about the audio caps and I went by your advice on what caps to get for that.

It might be irrelevant but it appears that also the floppy (!) could use a recap: in my case the whole system started freezing when it tried to access a floppy disk.

I started looking at the logic board, reflowed the floppy controller and the chipset asic but it did not help. Then I found a reference on some forum that someone had the same issue and replacing the drive solved it for them. So I decided to look at the floppy drive and indeed at least a miniature 1uf/50v cap (C106 on MFD-75W-01G drive) had leaked. I replaced all electrolytic caps on the drive and no more freeze on floppy access. Such a weird issue!!!

 

[JDW]

...I decided to look at the floppy drive and indeed at least a miniature 1uf/50v cap (C106 on MFD-75W-01G drive) had leaked. I replaced all electrolytic caps on the drive and no more freeze on floppy access. Such a weird issue!!!

Here's the Mouser Cart I used to recap my 1.44MB floppy drive.