Help with vmod!

[yaboc]

hey,

i just finished modding my True Control 550

i used

10ohm + 1k on 3.3V
33ohm + 10k on 5v
66ohm (2 x 33ohm in series) + 10k on 12v

i did everything inside the psu casing and now when i try to power up the psu, it just spins the fans and nothing happens. i tried connectin it to bare mobo too and start it up but the same things happens? possibly shorting out somewhere? i isolated all joints good.

one strange thing is that there's that connectivity test tells me that there's connection between 5v rail and ground, and not between the ground and any other rail. so is 5v rail shorting out? LMK what you guys think.

yabOC

[yaboc]

ok i checked everything and it turned out that 12v was shorting out on the PSU casing. so i isolated the joints with electric tape better and everything worked fine. i jumpstarted the PSU but turning the VR on any rail didnt change the voltage. i double checked the connections and everything seems fine. xtremesystems member Nebulous had the same problem and he said that taking off fixed resistors helped him to solve the problem. i'm gonna try this later on, but i would like to know why it is so. PSU is Antec True Control 550. any help is appreciated. thanks

yabOC

[Hell-Fire]

As far as I recall, for the Antec line of psu's, you have to use a fixed resistor inline with a VR in order for the mods to function.

You dont have to use anything real specific, so forget whatever you read elsewhere.

How I do them is to take a 40-70 ohm fixed and solder it between the cut sense wires. Then solder a wire to the top of that fixed resistor that then leads to the middle leg of your VR. Sometimes people want to make a mod sound cooler, or what not, by coming up with all these different configurations on how to do it. I used a 47ohm fixed and a 10K VR for every rail, and its been rock solid and steady ever since.

The same applies for every rail modded. Sounds to me like you are not properly grounding the VRs. I soldered molex plugs to my VRs and plugged them into those 2 Fan Only molex connectors that are on the psu. You can always strip away some insulation off the black Ground wires in the ATX connector and solder your ground wires to that.

[yaboc]

hey Hell-Fire

i did exactly as shown on the pic, with the difference that i did everything in the case. i triple checked for connectivity and that nothing is shorting out. btw PSU is turning on now opposed to before when it was shorting out. so there's definitely something wrong. Nebulous had similar problem. i'm gonna try just VRs alone on all three rails and see how tiz going to work out. anyway i 1 K on 3.3 is OK or should i go with 10k. im not gonna adjust the voltages on the fly but will there be less fluctuations using greater resitance potentiometer ? thanks

yabOC

[yaboc]

damn it , i took off the fixed resistors and still turning the VR doesn't work. any ideas?

i did everything like on the pic exept the fixed resistors. HELP!

[Hell-Fire]

For the Antec supplies, you HAVE to use the fixed resistor or the mod will not work.

I would use the same fixed resistor for each sense line, and I use the same VR for each rail as well...although you can use 1K-3.3v, and 10k for both 5v/12v rails.

I typically use the same fixed and VR just fomr simplicity sake.

Remember not to use the face plate after the mod for the TC line, and to check the grounds.