Replacing LG PSU LGP32-11P with LGP32-09P?

[bdorset]

What resistor(s) do I have to change to reduce the standby voltage from 5V to 3.5V? See attach photo. I have several brand new LGP32-09P that could be dead stock so am trying to use them to replace LGP32-11P. The amps and voltage rating are written on both supply and are the same except for the standby voltage. I also know that the arrangements of the voltages at the connectors are different but I can fix that problem. I just need to get the 5V down to 3.5V on the LGP32-09P in a professional way . Thanks for helping in advance.

[fbooktablet]

Re: Replacing LG PSU LGP32-11P with LGP32-09P?

Change R204 to 1.5k resistor in the red rectangle..

[bdorset]

Re: Replacing LG PSU LGP32-11P with LGP32-09P?

Sorry it only took it down to 4.2V

[jetadm123]

Re: Replacing LG PSU LGP32-11P with LGP32-09P?

1.5k should be the correct value. The resistors used in the schematic are 1% precision resistors. Are you using a 1% resistor? Measure the value of the resistor with your meter to determine it's actual resistance.

[budm]

Re: Replacing LG PSU LGP32-11P with LGP32-09P?

BTW, when you bring down the Voltage from 5V to 3.5V, you need to adjust the value of R205, 206, 207 according otherwise the Opto current transfer will not be correct.

[bdorset]

Re: Replacing LG PSU LGP32-11P with LGP32-09P?

I did used 1.5k @ 1% and I did test before I install

[bdorset]

Re: Replacing LG PSU LGP32-11P with LGP32-09P?

I think I can solve the problem if I get a schematic Diagram for EAY60868901 LGP32-10P, EAX61464001 power supply

[arenat]

Re: Replacing LG PSU LGP32-11P with LGP32-09P?

You can´t go below 4,5v with a zener programmable , ic201 , which have a reference voltage of 2,4v .
Change it with an az431 1,24 v reference voltage.