Modern Power Supply to replace the bricks of old

[TheEditor]

As we all know our machines are hitting close to the half-century mark and the power supplies are tending to die and take the computer with it to death.  That being said I am in search of a replacement power supply for the 400/800 series computers and peripherals as well as the XL and XL series.  First, the 400/800, which my research shows 9V AC output.  Would this work as a replacement?

 

https://www.amazon.com/Adapter-Regulated-Switching-Interchangeable-Equipment/dp/B0BFPXZ7S1

 

I am also looking to recap everything I can to avoid the blown cap issue as well.  Does anyone know the needed caps to make this happen?

 

Thanks

[Nezgar]

400, 800, 810, 1050 and a few others need 9V AC output at various minimum amperages. Your linked adapter outputs 9V DC, not AC.

 

Youll have to search a bit more for one with AC output - they are usually bigger bricks. With that said, because of the simple transformer circuit of AC stepdown transformers, the original bricks are usually perfectly safe to keep using if that's your concern.

 

Edit: Also, you need a barrel connector size of 5.5mm outer, 2.5mm inner. Watch out for the more common 2.1mm inner barrell size connectors nowadays.

 

[Panther]

The label doesn't actually specify the output, and the description mentions DC in some places.  I suspect this is actually a DC adapter.

 

[_The Doctor__]

No need to replace the stepdown transformer power supplies (AC). Most Atari power supplies can rebuilt for very little money. The epoxy filled US boat anchor supply is the only one that needs the cords cut off and transplanted to a quality power supply, usually mean well supplies provide clean solid DC power and can fit inside old Atari power brick plastics.

 

AC output supplies normally only need the fuse replaced if they blow.

 

DC normally only need a 7805 regulator or caps maybe a fuse very rarely diodes if ever

Edited January 18 by _The Doctor__

[TGB1718]

7 hours ago, TheEditor said:

https://www.amazon.com/Adapter-Regulated-Switching-Interchangeable-Equipment/dp/B0BFPXZ7S1

That is a switching regulator therefore the output is DC, I just hate these sort of adverts, as they imply the output

is AC where as the term AC is only there for the input voltage.

 

Typical of a seller who has no idea of what he/she is selling.

 

Also noted what @Panther said, no output voltage printed, doesn't say much for the quality if that's not there.

[mimo]

8 hours ago, TheEditor said:

the power supplies are tending to die and take the computer with it to death

Really?

After 30+ Atari 8bit computers owned in the last 20 years I've had no failed power supplies or faulty caps.

 

[Rybags]

Yeah - a transformer is formulaic (is that a word?) in that the resultant output is a function of the ratio of windings so shouldn't change.

Though I guess if insulation was shedded it might.  If a winding was severed it'd probably just stop working altogether.

 

But in my own experience - the problem I have with one of my trapezoid shaped AC adaptors is that the plastic has cracked and broken which can expose hazardous voltages - my fix has been to duct tape the thing to hold it together.

[TGB1718]

Have to agree with @mimo still have all my original PSU's both AC for 800/1050 and the house brick ones

for my XL and 130XE's and have never suffered a failure.

 

11 hours ago, TheEditor said:

https://www.amazon.com/Adapter-Regulated-Switching-Interchangeable-Equipment/dp/B0BFPXZ7S1

I also noticed it has the EU CE marking which implies it conforms to European Standards, one of which is clearly

marking input and output voltages and either the current rating or VA (Watts).

Only the input voltage is marked, so it's a cheap knock off DC PSU.

[+kheller2]

There is no need to replace the power transformer.  It isn’t a “power supply” in the conventional laptop sense.  It’s just a pile of copper windings.  If you want to save electricity, unplug it when not in use: power strip with a switch. Unlike every other modern vampire voltage sucking thing we have laying around the house. 
 

As for blown caps, sometimes they dry out, sometimes they get shorted out.  Remember this stuff is from the 70s/80s and should not be lumped in with the bad / fake china cap fiasco Capacitor Plague of the 00s.   It is RARE that caps need to be replaced on these Atari’s.  

[DustyCity]

I used to play guitar a lot, and my original Line6 POD (not sure if they’re still around or not) used a 9VAC 2A with a barrel that fits the 800/400. I’ve used that adapter for my 800 with no problems. You may have an easier time trying to find a new match for that device than anything Atari-specific. 

[Chri O.]

This only applies to XL/XE series of Atari 8-bit computers. Please double check the pinouts for 1200 and 1400 XL.

I was able to find some cool PDF file online. ( schematic diagrams ) Atari XL XE Power Supplies.zip

[Beeblebrox]

posted this a few times before on other threads, but if you are in the UK I use the following all the time for the 400, 800, 1200XL. It's a very well made and reliable, very reasonably priced. (Again as has been mentioned this is not for the XL (800XL or 600XL) or XE range, which take 7pin din plugs and different power requirements)

 

9v 2amp 18va AC power adapter. You just need a 2.1mm to 2.5mm end plug adapter:

 

https://www.poweradaptorsuk.co.uk/2000ma-2a-9v-18va-acac-ac-output-mains-power-adaptor-162-p.asp

 

https://www.ebay.co.uk/itm/174950199535

 

 

Edited January 18 by Beeblebrox

[ACML]

The good old CO17945 9VAC 50W is awesomely reliable.  Best to buy the ones made in Japan vs Taiwan.  They are both great and will last, but the fuse is the weak link and the Japanese made ones have four screws under the feet to easily access the fuse.  The Taiwan made ones are sealed and you pretty much have to cut them open with a Dremel tool and the shell is disfigured. 

 Taiwan

 

Japan

 

 

The CO17945 is 3.4 Amps and can power addons like SIO2SD, Fujinet, Sdrive MAX easily with plenty of margin.

 

 

Edited January 18 by ACML

[pcrow]

I have several that are dead.  My 800 died, and it died in a nasty way such that if you try to turn it on, it will kill the power supply.  I'm guessing there's a fuse in the supplies that I can replace.  There was a guy in my users group that would fix them for the computer store where we held our meetings.  I think he said he just replaced fuses.  I haven't seen him in forty years, or I would ask him.  (It's too bad the 800 needs +12v, +5v, and -5v, unlike the newer XL/XE systems that are just +5v, so I can't just convert it to USB power.)

 

So story aside, any tips for repairing dead Atari 9V power supplies?

[TGB1718]

6 minutes ago, ACML said:

Japanese made ones have four screws under the feet to easily access the fuse.

The UK ones have metal rivets, so easy to drill out, I had the wire where it enters the PSU break

on a 1050, was easy to drill it, repaired the wire, then used screws/nuts to secure it back together.

 

You can see the rivets in the photo of this 800 PSU

 

[Beeblebrox]

25 minutes ago, TGB1718 said:

The UK ones have metal rivets, so easy to drill out, I had the wire where it enters the PSU break

on a 1050, was easy to drill it, repaired the wire, then used screws/nuts to secure it back together.

 

You can see the rivets in the photo of this 800 PSU

 

Ah and those particular ones in the pics have the rare 2.5mm(?) power jack for the 410 cassette decks. I've a load of these Ingersol psu's for the 400/800 and 1200xl and 1050/810 drives but none with the little jack. 

Edited January 18 by Beeblebrox

[TGB1718]

3 minutes ago, Beeblebrox said:

Ah and those particular ones in the pics have the rare 2.5mm(?) power jack for the 410 cassette decks.

Yes, one of these, very first 410 model, you can see it's just a converted audio cassette deck, it even has a slide out carry handle

 

Still have it, but doesn't work very well and I can't really be bothered fixing it as I would never use it, have a working XC12 for that if needed.

 

[djglish]

I bought a power supply from 8-Bit Classics for my XEGS.  They also carry an AC power supply for the 800 series.

Here is the link

https://www.8bitclassics.com/product/atari-400-800-1050-ac-adapter/

[Chri O.]

6 hours ago, pcrow said:

I have several that are dead.  My 800 died, and it died in a nasty way such that if you try to turn it on, it will kill the power supply.  I'm guessing there's a fuse in the supplies that I can replace.  There was a guy in my users group that would fix them for the computer store where we held our meetings.  I think he said he just replaced fuses.  I haven't seen him in forty years, or I would ask him.  (It's too bad the 800 needs +12v, +5v, and -5v, unlike the newer XL/XE systems that are just +5v, so I can't just convert it to USB power.)

 

So story aside, any tips for repairing dead Atari 9V power supplies?

Ebay :10Pcs T5AL250V 5A 250V Axial 5 Amp SLOW Blow Fuse Time Delay 3.6x10mm 

[_The Doctor__]

 

[Chri O.]

🙂 ^^^^^^^^^^ 

 I did this cutting with knife not too long ago when I end up with two dead power supplies.

[_The Doctor__]

???? how would you end up with two dead supplies? That makes zero sense. The plastic box comes off, and you replace the fuse. If you some how slip and cut a wire you simply shorten the wire. The power supply is a step down transformer. You don't cut deeper than the plastic. You don't insert the implements deep enough to hit the internal parts. If you want to use a hammer and pound all the way into the transformer, that would not qualify as being careful then would it?

 

Over the years since these were first manufactured I have done this countless times and can't recollect a single using not being repairable.

 

Using the same method to get into the DC supplies that don't have screws to gain access pretty much the same. Still able to replace the other parts. I suppose a person could accidently cut a trace but in a power supply a quick scrape of the solder mask and bridging with solder at the scrape would also fix that. The power supplies are dead simple to fix. I haven't seen a fried transformer yet, unless someone bypassed the fuse etc.

Edited January 19 by _The Doctor__

[BillC]

10 hours ago, pcrow said:

I have several that are dead.  My 800 died, and it died in a nasty way such that if you try to turn it on, it will kill the power supply.  I'm guessing there's a fuse in the supplies that I can replace.  There was a guy in my users group that would fix them for the computer store where we held our meetings.  I think he said he just replaced fuses.  I haven't seen him in forty years, or I would ask him.  (It's too bad the 800 needs +12v, +5v, and -5v, unlike the newer XL/XE systems that are just +5v, so I can't just convert it to USB power.)

 

So story aside, any tips for repairing dead Atari 9V power supplies?

AFAIK the only components on the 400/800 that use -5VDC are the 4116 DRAM and the power LED, if the 4116 are eliminated by a RAM upgrade and the power LED rewired to use +5VDC this should eliminate the need for -5VDC. I also believe that +12VDC is only used by the 4116 DRAM, the color adjustment potentiometer, and SIO pin 12.

Edited January 19 by BillC

[pcrow]

3 minutes ago, BillC said:

AFAIK the only components on the 800 that use -5VDC 

That got cut off.  I'm under the impression that the answer is the RAM, and if I put in a new board that uses SRAM, then I don't need -5V anymore.  And I'm not sure anything uses the +12V other than the SIO pin, and that was dropped on newer systems, so nothing I have or ever will have will use it.  So if that's correct, I could put in a USB plug instead of the power plug, and get rid of all the power management.  I have a dead 32K RAM board already, so the RAM upgrade would make sense.  (It was a third-party board; I think it was Mosaic if I remember correctly  I had help repairing it once back in the 80s, but it failed again, and I think I messed it up more with my soldering kills.)

[TGB1718]

10 hours ago, djglish said:

https://www.8bitclassics.com/product/atari-400-800-1050-ac-adapter/

Would be ok for an 800 and 400, maybe 1200XL too, but I wouldn't use one on a 1050, it's about 1 amp short of the Atari ones,

it might run ok, but I would think it would get very hot.