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LECLLC
1 Copper

Replaced an Optiplex 755 Power Supply and now have no video feed

We replace the existing power supply (model no. L305P-01) with a new power supply (model no. N305P-06) and the computer will come on put we are not getting a signal to the monitor.  Are the two power supplies similar?  Really not sure where to go next and any help/direction would be appreciated.

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7 Replies
7- Thorium

RE: Replaced an Optiplex 755 Power Supply and now have no video feed

These units should both work on a 755 Mini Tower.   The DL2032 battery may need replacement.

Take out all ram and it should beep low and slow.

beeep  beeeep  beeeep beeep

Then add 1 ram stick.

Sort thru each chip one at a time which should be matching pairs of ram.

 


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Moderator
Moderator

RE: Replaced an Optiplex 755 Power Supply and now have no video feed

L305P-01 = NH493 305w Liteon PSU
N305P-06 = C248C 305w Delta PSU

They are both on the Optiplex 755 parts page. Does the PSU fan and fans in the Optiplex 755 spin up on boot?

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LECLLC
1 Copper

RE: Replaced an Optiplex 755 Power Supply and now have no video feed

I re-reseated the memory and now the monitor is working.  However, the back USB ports will not work for the mouse and the keyboard.  I plugged the mouse and keyboard into the front USB ports and they are working.  Any clue as to why the back USB ports would not be working?

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Moderator
Moderator

RE: Replaced an Optiplex 755 Power Supply and now have no video feed

Check the bios and see if there is an option to Enable them.

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LECLLC
1 Copper

RE: Replaced an Optiplex 755 Power Supply and now have no video feed

yes both fans are spinning and the computer seems to be working other than the back USB ports which were working before the PSU upgrade.  For some reason reseating the memory seems to have brought the computer back online.

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LECLLC
1 Copper

RE: Replaced an Optiplex 755 Power Supply and now have no video feed

I would need to do that at bootup correct?

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Moderator
Moderator

RE: Replaced an Optiplex 755 Power Supply and now have no video feed

Correct, press F2 on restart.

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