[SOLVED] Voltage Problem: -15V pins are only at -5V
Posted: Nov 22nd, '19, 14:08
Hey fellow builders! Today I ran in a serious problem (at least I think so) after finishing the ride/crash section. When I plug in the PSU cable and check the voltage control points, I measure about 5V at the ICs and about +15V at the square marked pins of the op amps. So far, so good - but at the round control points of the op amps, where I should measure -15V, I only get about -5V, everywhere on the whole board 
What is wrong here?? How do I debug this and identify whats draining that power from there, lowering the voltage so much? The only thing I can think of is a shorty somewhere, working as a voltage divider, but I've got absolutely no idea on how to identify this. I already rechecked the PSU, but if not plugged in, it works as expected and outputs the adequate voltages.
I feel like I didn't make any mistake, like I doublechecked every component for the right polarity on the way, and didn't solder above 290°C anywhere, not staying on any solder joint for longer than a few seconds ... but still, this seems to be broken.
UPDATE:
So far I've changed the 7915 Voltage Regulator on the PSU for a fresh replacement with even better specifications (should hold until 1.5A), wrong voltage stays. Since it must be a short than, I'll have to find it. But how do I do that? I've got absolutely no experience in the field
The only reasonable solution I came up with is thermal imaging the board- but after I googled for IR cams, I hat to discover that suitable imagers cost a shitload of money. Any suggestions how to approach my problem with limited resources? And could somebody provide me with an 1.02 BRD-File? I just find the 1.0 available for Download ...
What is wrong here?? How do I debug this and identify whats draining that power from there, lowering the voltage so much? The only thing I can think of is a shorty somewhere, working as a voltage divider, but I've got absolutely no idea on how to identify this. I already rechecked the PSU, but if not plugged in, it works as expected and outputs the adequate voltages.I feel like I didn't make any mistake, like I doublechecked every component for the right polarity on the way, and didn't solder above 290°C anywhere, not staying on any solder joint for longer than a few seconds ... but still, this seems to be broken.
UPDATE:
So far I've changed the 7915 Voltage Regulator on the PSU for a fresh replacement with even better specifications (should hold until 1.5A), wrong voltage stays. Since it must be a short than, I'll have to find it. But how do I do that? I've got absolutely no experience in the field
The only reasonable solution I came up with is thermal imaging the board- but after I googled for IR cams, I hat to discover that suitable imagers cost a shitload of money. Any suggestions how to approach my problem with limited resources? And could somebody provide me with an 1.02 BRD-File? I just find the 1.0 available for Download ...