520ST - Is This The Correct Power Supply?

[800_Rocks]

Hi - TIA for any replies!!

 

1) Can you confirm if this is the correct power brick for the 520ST?  

 

2) Where is a good source for such information on the ST line?

 

3) Is there a great FAQ for the ST line like the one Michael Current maintains for the Atari 8bits?

 

4) Can you share a diagram of the pin-out of the power brick so I can test it?

 

 

 

[snarkdluG]

1. No. It looks that it is for the external floppy drive SF314/SF354. Power for 520ST, 520ST+ and STM has this connector.

 

https://docs.dev-docs.org/ has a lot of manuals and other information. Not what you are looking for but great non the less.

[800_Rocks]

OK my bad… I found this 2nd power brick and believe it is for the 520ST. It is much longer and has the DIN 7pin female plug. I will test both power bricks and clearly label them. 
 

 

 

 

 

[800_Rocks]

When I test the 520ST power supply (pictures in most recent prior reply) I get good +12V and -12V however both of the +5V pins are measuring +14.63V  nearly 3X what they should!!!  So it would seem this power brick is bad.  How common is this with the original 520ST power bricks... after so many years?  Is there a good source for a modern replacement?  With a 3X over-voltage what else on this board may be fried?  OR does this board have any safeguards against such an over-voltage?

 

This is the same 520ST I have another post about a frozen on/off power switch.  In the 2nd picture below we see the switch is rated at DC 5V  1.5A.  So it looks like the power supply went bad and maybe it fused the switch with 14.63V instead of its rated 5V

 

 

 

[snarkdluG]

I'm unsure if you can measure without a load on the PSU. But it seems high even without a load.

 

Anyway, CenturionTech have one.

[800_Rocks]

9 minutes ago, snarkdluG said:

I'm unsure if you can measure without a load on the PSU.

For a complete novice.... How would I put a load on the PSU for a more accurate measure?  TIA

[+DarkLord]

Exxos's Store and Forum are great places for advice/parts

for revitalizing our beloved ST computers.   

 

https://www.exxosforum.co.uk/atari/store2/

 

https://exxosforum.co.uk/forum/index.php

 

Hope this helps...

 

[+remowilliams]

My 520STf power supply without a load, measures 5.18V on the 5V lines.