Atari 400/800,1050 PSU Quick & Dirty Repair

[RodLightning]

I put a new fuse in one of my old CO17945 power supplies tonight. This particular one has been out of service since around 1990.

I used scrap wire from my parts box to wrap around the fuse. A bit of hot glue holds it together.

I'm posting pictures here because images of a cracked open C017945 seem to be lacking on the internet.

 

I am neither proud nor ashamed of my ugly repair. I needed it to work again, so now it does. If the fuse blows, it should be easy enough to pull apart and replace they way I did it.

 

I will say that the rising cost of parts like inline fuse holders, boxes etc. borders on extortion.

 

This one will be used with a second 1050 floppy drive.

 

 

[oryan_dunn]

How did you open the case? I have two c017945 that both blew. I was a bit of an idiot plugging the second one in. I have a 400 and I had moved some things around, and when I powered it up, after about 2 or 3 seconds, it blew. I thought that was odd, and thought it must just have been the power supply going bad, so I plugged in the other one, and it blew after 2-3seconds. It was clearly the 400 that had an issue. I took it apart, and I think I know what caused the issue. The RF cable comes out from near the front, all the way to the back, and is wrapped around a ferrite donut. Very close to that, is a little plastic clip, that *was* stuck to the inside of the case. When I opened the case, the clip was not sticky any more. My guess is that when I moved the 400, the ferrite donut must have shorted out a couple pins, which caused the fuse to blow.

 

I've ordered a couple more supplies, but I'm curious that I may want to try replacing the fuse in one of the old ones to see if that works before I plug in the new ones I bought.

[Bikerbob]

I would like some tips on getting this open as well. Getting a knife in the gap is not working well for me.

 

James

[RodLightning]

It's not very elegant, but I originally used a hot knife edge on a soldering iron to melt a slot into one corner. The one I have has a bell shaped plastic top and a flat bottom piece where the transformer sits. It can be cracked or cut open along the bottom seam between pieces, once you mange to get a cut started. I used a flat screwdriver and pocket knife. It took a while.

 

A dremel tool with cutoff wheel might work better and produce a cleaner cut along that bottom edge. The bell shaped top piece just lifts off once you cut through the seam on all four sides along the bottom, where it is sealed. I think some of them had four screws and could be opened! The ones I have seen are all sealed.

[gargoyle]

I use a cutting disk with a dremel tool to open mine, and use hot glue to reassemble the enclosure. I wouldn't recommend using hot glue to hold the fuse wire in place as the glue will definitely melt or get soft when the adaptor warms up (and they do warm-up)

Edited March 24, 2017 by gargoyle

[cleoo]

On 3/24/2017 at 9:28 AM, gargoyle said:

I use a cutting disk with a dremel tool to open mine, and use hot glue to reassemble the enclosure. I wouldn't recommend using hot glue to hold the fuse wire in place as the glue will definitely melt or get soft when the adaptor warms up (and they do warm-up)

I found this post and wondered how to do it myself. 

 

I used a Dremel cutting disk and cut horizontally about a quarter inch into the plastic, which won’t hit any vital, unseen transformer parts.

 

I cut around the cords because I didn’t know the bottom part of that section is not glued to the bottom. 

 

Next time, I’ll just cut horizontally around the 3 sides and cut just a little deeper near the corners by the cords. I used a thin screwdriver to pry the plastic apart. 

 

I’d recommend a fan since the cutting of this plastic produces smoke and fumes that probably aren’t healthy. 

[RodLightning]

Looks good.  The sealed ones were never meant to be opened. Many perfectly good transformers probably went into the trash as a result of that short sighted and cheap design.  For a few more pennies per unit, they could have been made with replaceable fuse holder, accessible from the outside.

[Stephen Moss]

13 hours ago, RodLightning said:

Looks good.  The sealed ones were never meant to be opened. Many perfectly good transformers probably went into the trash as a result of that short sighted and cheap design.  For a few more pennies per unit, they could have been made with replaceable fuse holder, accessible from the outside.

Really? I think it looks terrible, if I found that in the wild there is no way I would plug it into anything that I owned.

 

I think that to say a sealed unit design was short sighted is an over statement, first the expected lifespan of most products is 10-15 years and so the expectation at time of manufacture would be that the unit and its power supply would be discarded long before it was likely to fail, not that the items would still be in use 30-40 later.

Second, the idea of a sealed unit was precisely to stop people (who generally don't know what they are doing) from tampering and trying to affecting repairs, because if done incorrectly and it subsequently lead to an electric shock or destroys the item it is powering the manufacture can clearly point to the very evident tampering/self repair and say it's not our fault, it would have been fine if someone had not not tampered with the PSU.

 

Would it not just be easier and more reliable to find another 9V, 3.5A DC power unit with the correct polarity (and size adaptor if necessary for the DC power Jack to get the correct fit).

[RodLightning]

On 4/26/2024 at 2:33 AM, Stephen Moss said:

Really? I think it looks terrible, if I found that in the wild there is no way I would plug it into anything that I owned.

 

I think that to say a sealed unit design was short sighted is an over statement, first the expected lifespan of most products is 10-15 years and so the expectation at time of manufacture would be that the unit and its power supply would be discarded long before it was likely to fail, not that the items would still be in use 30-40 later.

Second, the idea of a sealed unit was precisely to stop people (who generally don't know what they are doing) from tampering and trying to affecting repairs, because if done incorrectly and it subsequently lead to an electric shock or destroys the item it is powering the manufacture can clearly point to the very evident tampering/self repair and say it's not our fault, it would have been fine if someone had not not tampered with the PSU.

 

Would it not just be easier and more reliable to find another 9V, 3.5A DC power unit with the correct polarity (and size adaptor if necessary for the DC power Jack to get the correct fit).

Well, a poor design is a poor design.  Some have screws and are easily openable.  Those 9vac transformers can last for decades.  The fuse can blow if the supply was left plugged in and whatever it is powering is disconnected at the other end and later reconnected. If the output happens to spark when plugged back into a drive or computer, it's enough to blow the fuse.  I have seen it happen.  There is nothing wrong with replacing a fuse.  Would throwing a perfectly good transformer into e-waste be more responsible, because the damned thing is glued shut?

 

I have no desire to argue which people know what they are doing.  If changing a fuse is too difficult for some people, by all means let them buy a brand new replacement.  Many of us still tinkering with 40 year old computer hardware are capable of cutting through plastic to change a fuse.  It's well within our skillset.  I would rather see an original power supply restored and in use, than replaced.  The plastic can be filed down, resealed with glue, or the transformer put into another enclosure entirely if that would better suit your sensibilities.

I respect anyone who makes the effort to tear one down and put it back together.  This point of view is best described in ifixit's self repair manifesto:

 

https://www.ifixit.com/Manifesto

[_The Doctor__]

 

[Meall]

I am revising an older thread, but I was looking at information about this PSU for the 1050 disc drive. Is there any caps that could need replacing in this device to use it safely?

 

since it is quite difficult to open, I’d like to know if it is even worth trying before I break the casing. 
 

thanks

[SoundGammon]

On 9/8/2024 at 10:21 AM, Meall said:

I am revising an older thread, but I was looking at information about this PSU for the 1050 disc drive. Is there any caps that could need replacing in this device to use it safely?

 

since it is quite difficult to open, I’d like to know if it is even worth trying before I break the casing. 
 

thanks

There's no caps in the PSU power supply. It's just a transfomer to reduce to voltage down to 9 volts ac.

 

I wonder if a hack-saw would work to cut the sides?

[Meall]

19 hours ago, SoundGammon said:

There's no caps in the PSU power supply. It's just a transfomer to reduce to voltage down to 9 volts ac.

 

I wonder if a hack-saw would work to cut the sides?

Great. That’s what I was thinking just by looking at the pictures showing the interior of the PSU on this page, but wanted to confirm. I measured it and it gives a 10.5V steady, which is probably good I guess. 
 

thanks