Wrong voltages on power supply section

Hi guys!

After soldering together the power supply section of my SMR-4 I get the wrong voltage at the red points.

Input: 12V

7805 compared to ground (from left to right when the audio connectors points down):
17.3V - 15.6V - 15.5V

The green and the blue points all work fine.

Any idees on where to look?

Hmmm… Higher values on the 7805 than on the Input??? Could you please measure the Input Voltage on the Jack?

Are you shure its set to DC ??

Haha, sorry. My DC jack must be a 18V then. I’ll get a new one tomorrow.

After looking a bit more on the schematics could it be that I have broken 7805 in solding?

IC1 pin 5 and 8 are giving ±16.5V. Should be correct.

7805 are all showing positive voltages. Should not the one in the middle be ground which wold mean that it should show 0V when comparing to GND? What could cause this?

Or could it be C19 has a bad connection?

IF the Mid GND pin of the 7805 shows anything else than 0V you should check for a bad solder joint there…

Looking at the soldering again (was made a long time ago) there is no wonder it didnt work… Second try starts now!

Hm, how did I manage to screw up so badly for 2 years ago? A fresh start, no “burned solderings” and a new filter board is in the mail…

At least I know that I have gotten better :slight_smile: