Re: plus4 power supply

From: Gerrit Heitsch <>
Date: Wed, 19 Sep 2012 21:40:25 +0200
Message-ID: <>
On 09/19/2012 09:25 PM, Hegedűs István wrote:
> Hi,
> I have done a major repair service on my plus4 power supply. Replaced
> the electrolyte and tantal capacitors, the diodes. Now it supplies 5.6v
> while before it supplied 5.4v. Is it dangerous for the plus4? What
> should be the voltage level of a normal power supply? (Note that I have
> only a multimeter and no scope so might be measurement difference).

It shouldn't go above 5.2V. You should do a complete rework of the power 
supply remove the existing regulator, get a switching regulator, for 

This one is adjustable, so adjust to 5.2V _before_ connecting the Plus/4.

As a sideeffekt, the PSU will run much cooler.

If you feel _really_ adventurous, you can put a complete switching power 
supply that runs on 230V and supplies 5V 2A into the empty part of the 
Plus/4 PSU. The transformer will then only be used for 9V AC.
But since one has to work on 230V AC, this is only for people who know 
exactly what they're doing.


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Received on 2012-09-19 20:00:04

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