Fixing Low Voltage On 1.6 Psu Options

[venomusss]

Hi All,
Finally decided to get out my old XBOX and modify and Upgrade it. I installed a larger hard drive and everything seemed to be working fine. After a couple times of using it, it would give me error code 7. I opened it back up and put in the stock hard drive. The XBOX powered up and worked perfectly. I then put in the upgraded hard Drive and error code 7 again. I hooked up an external power supply to the hard drive and booted the XBOX. It worked perfectly with the upgraded Hard Drive.

I then checked all the voltages with a meter on the stock 1.6 power supply. They are all low. The 5 volt shows 3.9 and the 12 volt shows 9.57
Apparently the stock drive and motherboard can get away with running at those low voltages , but the new drive needs more power.

I am not a genius when it comes to repairs, but I have been able to make my way through them on various electronic items for many years. I have always shied away from power supply repair, but as these XBOX units are getting older and harder to find. I might need to learn a little more for the future

Can anyone steer me in the right direction to troubleshooting the repair of the low voltage? The power supply is a Delta DPSN-96BP. I have inspected it thoroughly and see no signs of leaking or swelling of any caps. I know that does not mean they could be bad though. I see no burn marks and nothing smells funny.

Thanks for any help. Chris

[shambles1980]

There is a potentiomiter on the top of the psu (farthest away from the 8 pin input connection) "little white plastic philips screw in a blue plastic case thing usualy"
You can twist that slightly. id say anti clockwize but it depends on the way your looking at it..

just twist it slightly and measure the voltages as your doing it.

But you should probably check for dying / dead caps.

you dont need to get the 12V rail up to 12v though. 11.6 or so would be fine. but check the 5v as well as that could be going higher than 5v whilst the 12v stays below 12..
So you may end up with something like 11.4v (12v) and 5.1V (5v) that should be fine also. but try to get them both as close to the correct voltage as possible. (preferably slightly lower)

This post has been edited by shambles1980: Mar 29 2012, 06:46 PM

[venomusss]

There is a potentiomiter on the top of the psu (farthest away from the 8 pin input connection) "little white plastic philips screw in a blue plastic case thing usualy"
You can twist that slightly. id say anti clockwize but it depends on the way your looking at it..

just twist it slightly and measure the voltages as your doing it.

But you should probably check for dying / dead caps.

you dont need to get the 12V rail up to 12v though. 11.6 or so would be fine. but check the 5v as well as that could be going higher than 5v whilst the 12v stays below 12..
So you may end up with something like 11.4v (12v) and 5.1V (5v) that should be fine also. but try to get them both as close to the correct voltage as possible. (preferably slightly lower)

The potentiometer makes a slight increase to maybe 4.2 volts and 9.97 volts, nothing higher than that. I will start testing all the caps. Thanks for the reply.

[venomusss]

There is a potentiomiter on the top of the psu (farthest away from the 8 pin input connection) "little white plastic philips screw in a blue plastic case thing usualy"
You can twist that slightly. id say anti clockwize but it depends on the way your looking at it..

just twist it slightly and measure the voltages as your doing it.

But you should probably check for dying / dead caps.

you dont need to get the 12V rail up to 12v though. 11.6 or so would be fine. but check the 5v as well as that could be going higher than 5v whilst the 12v stays below 12..
So you may end up with something like 11.4v (12v) and 5.1V (5v) that should be fine also. but try to get them both as close to the correct voltage as possible. (preferably slightly lower)

I borrowed an ESR meter and found two bad caps one 47uf 25 Volt and one 100uf 25 Volt. I replaced them and was then able to adjust the pot up to the correct voltages.
The fix seemed to easy, but it is working. Thanks for the help.
Chris