Hi!

recently i bought a new power supply for my PC...unfortunately i can't connect the front LCD panel of my computer case because the old PSU had
a small connector comming out and the new one is not designed to have one.

The connector has 3 wires... i measured the voltages comming out from and i'm getting 5V

BLACK 5V- (ground)
RED 5V+
PURPLE 5V+ (5V+ standby)


these wires are connected to the correspoding ones of the ATX connector,
and i don't understand why it uses 3 wires and why it take the 5V+ from the purple wire of the ATX connector, i'm not willing to open the PSU so i can connect the way it was in the old PSU... can somebody help me so i don't mess anything?

 

The LCD panel was likely active or could be activated when in standby, so it would require 5VSBY. I don't see any reason to crack open the PSU. Just open the insulation on the corresponding wires in the main 20 pin harness, solder the wires together then tape them up.

 

when i'm saying that i don't want to mess anything it's mostly about the guarantee of the PSU.

what if i just give it 5V+ and ground? i'm wondering if everything is going to
be fine...

 

Seems odd if black is -5V. That means it needs a 10 volt supply. So supplying it +5V and ground (true 0) will either ruin the module or it just won't function. The LCD module isn't going to be drawing a lot of current so you should be able to get away using something like a header connector, or something thinner, like a trimmed needle/reem, to squeeze into the top of the 20 pin connector on the right voltage without hurting wiring, a needle/ream used to just wedge into the top of the connector a little for good physical contact should work fine and not disrupt anything, trim or shrinkwrap any extra wire/reap sticking out and make sure it's seated solidly and you should be fine. This is one thing Dremel tools are great for, mount a standard male .1" square header peg as if it were a bit and then use a grinding stone as if it were a micro lathe to give you a fine point, and then dull the point just a little so you don't kill anyone =)

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@sceadwian i did a small typo it's not 5V- it's ground! i'm sorry.

 

Then skip the standby, it should work unless the LCD has controls which lose memory on power failure. This is probably not a good idea, but I think most USB power buses are still active in standby so you could try to steal a +5V standby from a free internal USB connection.

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sceadwian i was thinking that if it doesn't hurt not to give it the 5V+ standby voltage then i should steal some power from one of the molex connectors of the psu... somewhere i got a male molex and maybe i can cut the wires and connect the body with the wires of the other connector going to the LCD panel... what do you think?

 

Sure, though whatever function the LCD serves will be reset every time the system goes into a power down mode.

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