Amiga 4000 PSU 120V to 230V

giandac

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Jun 24, 2018
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Country
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rome
Hi everybody,

I have a 120V power supply for the Amiga 4000 that I'd like to swap for a 230V version.:huh:

My PSU is a Skynet 120V.

I think it could be useful to compare the tech specs of the components of the input circuit
of the 120V model against the 230V version (of course the schematics are the same for both version)
and try to adapt the 120V.

Here the 120V

R15Ohm Thermistor
F1250V 5A
R4390kOhm 5%
C10.22uF 250VA
L1??
Z1Varistor 14k 275
C33300pF 250V
C43300pF 250V
C510nF 250V
C5Abypassed
L7??
L8??
C20.22uF 250VA

Anyone can provide the specs for the 230V version ?


Many thanks in advance for your support.

GD
 
Last edited:
Normally computer power supplies are identical between their 120V and 230V versions, except for a single wire jumper (sometimes a switch) that rearranges the configuration of the rectifier circuit. For 230V it is wired as a conventional bridge rectifier. For 120V it is wired as a voltage doubler rectifier. It has been quite a while since I have opened my 230V A4000 power supply, so I don't recall where the wire jumper is.

What I do know is that the 120V version has a model number of COM-915-C1, and the 230V version is COM-915-C2. A schematic for the COM-915-C2 can be found here: http://amiga.serveftp.net/Schematics/A4000_schematics/A4000_Skynet_PSU_schematics.pdf
The jumper or link should be located between the positive side of C2 and the top of the bridge rectifier. You can see what looks like a link on the schematic. The 120V version will not have this link. Adding the link should convert your power supply to 230V. Hopefully this should be marked on the PCB.

I would only change this link and apply power if you are 100% confident the link is correctly placed. It would also be very wise to first test the power supply on its own, without being connected to your A4000. If correct, the fan will run, if not, it should be very obvious something is wrong!
 
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