PowMax Leadman Robantron 12v mod?

[HKPolice]

I got a 600watt Robantron, which is just a leadman/powmax OEM unit. It has NO 5v or 12v sense wires, and no pots inside, how do I mod the 12v rail?

The PCB is different than the enermax, so there is no R82, or at least I can't find it...

Sometimes it will boot for 2 sec, then shut off. If I turn the PSU off for a while, then turn it back on, it'll be fine until I shut down, then sometimes it'll turn off after booting for 2 seconds again.

The 12v rail is at a low 11.6v with a P4 3.0C setup, I think the PSU is cutting off due to too high of an initial draw from the 12v rail. The 5v and 3.3v rails are at healthy levels though.

Please help! :(

[HKPolice]

Also, the model number is LP-6100F which basically uses the same PCB as the LP-6100D and E (400w and 500w models)

I can provide pics if anyone can help out.

Thanks

[enzoR]

post pics of the inside :)

[HKPolice]

http://img19.imageshack.us/img19/7903/IMG_0620.jpg
http://img19.imageshack.us/img19/5944/IMG_0621.jpg
http://img19.imageshack.us/img19/130/IMG_0622.jpg
http://img19.imageshack.us/img19/2448/IMG_0623.jpg
http://img39.imageshack.us/img39/5613/IMG_0624.jpg

[HKPolice]

Leadman is a very big OEM PSU maker, I'm pretty sure someone figured out rail mods for them?? :confused:

[Hell-Fire]

Whats on the chip labeled U2 on the PCB? Its on pic #3 between the green and grey wires.

Also, can you post the marking on the IC thats in pic #4 as well? Its got 4 legs per side, and has ATC on it.

[enzoR]

damn thats confusing. can u maybe post pics of the psu as one whole then if needed we can circle chips and you can take close-ups of the specific chip?

[HKPolice]

No probs, i'll get on it after i've prime'd for 24hrs, it's currently up 'n running:

http://www.xtremesystems.org/forums/showthread.php?s=&threadid=37825

I updated the IC7-G bios from 23 to 24 and one of the features was "better compatibility with certain PSUs" which seems to work since the PSU isn't shutting down anymore.

BUT, my 12v rail sags down to 11.5v :( multimeter reads 11.7-11.8 though

[STEvil]

picture #3 on far right (to left of "fan1") is that wire all by itself orange (kinda hard to tell)? May be the sense wire..

You can also take the PCB out of the case and examine the bottom for a sense trace, or the top for a sense trace...

edit

forgot you wanted 12v.. my bad :rolleyes:


Check around the +12 lead block on the back for traces leading to it from any specific IC's on the front.

[Hell-Fire]

I am leaning towards the chip marked U2 on the pcb...between the orange and grey wires.

HK, make sure they havent snuck the 5v or 12v sense wire(s) in the middle of the ATX bundle. I have seen that from time to time.