frusciante89
Newbie level 6
Hi everyone!
I'm using a power supply (mod. Oriel 68907) in my lab to power a 500W Xenon lamp for a solar simulator, but the power supply wasn't turning on yesterday (display off, fan off, etc.). I asked the manufacturer but since this is an old part (1999), they don't have support available and even not a schematic. What I was able to obtain was the pcb traces and the components mask (although the right part of the board is different since it appears to be a different board revision). I tried to match the info I have the best I could with Inkscape in order to try debugging this thing.
What I noticed is that there are 4 test points on top of this board, and only T1 reads what's expected, 12V. T2, T3, T4 all read zero (they are highlighted in blue in the attached picture to this thread).
Also, if I excite the VN10KLS transistor in the green circle (i.e. I check the continuity between ground and gate, thus supplying a small current input to the transistor), then the fan starts and the display switches on, and everything seems to work fine. When I remove the probe, everything blacks out again.
Do you have any idea of what could be wrong and what steps could I take to debug this?
I'm attaching the partial schematic I was able to obtain and the voltage measurements I took with respect to ground. The wall input comes, after the ON/OFF equipment switch, from the molex in the bottom left of the scheme
- - - Updated - - -
Here's a more complete layout
I'm using a power supply (mod. Oriel 68907) in my lab to power a 500W Xenon lamp for a solar simulator, but the power supply wasn't turning on yesterday (display off, fan off, etc.). I asked the manufacturer but since this is an old part (1999), they don't have support available and even not a schematic. What I was able to obtain was the pcb traces and the components mask (although the right part of the board is different since it appears to be a different board revision). I tried to match the info I have the best I could with Inkscape in order to try debugging this thing.
What I noticed is that there are 4 test points on top of this board, and only T1 reads what's expected, 12V. T2, T3, T4 all read zero (they are highlighted in blue in the attached picture to this thread).
Also, if I excite the VN10KLS transistor in the green circle (i.e. I check the continuity between ground and gate, thus supplying a small current input to the transistor), then the fan starts and the display switches on, and everything seems to work fine. When I remove the probe, everything blacks out again.
Do you have any idea of what could be wrong and what steps could I take to debug this?
I'm attaching the partial schematic I was able to obtain and the voltage measurements I took with respect to ground. The wall input comes, after the ON/OFF equipment switch, from the molex in the bottom left of the scheme
- - - Updated - - -
Here's a more complete layout
