eduardofsjr

U4: approximately 1 volt drop, both directions. U6: approximately 1 volt drop, just one direction U51: approximately 0.6 volt drop, both directions Parallel components affect measurements.

@Krisztoszteron I just measured 1.000 k ohm. It is possible to read “102” (1000 ohms) at R20 in my last picture too, if you need a picture reference of another board. At output, there are 4 capacitors (3300 uF 80V)

@Krisztoszteron, thanks for the information! Now I’m sure this transformer needs repair on my board. About your case: There are few components on the left side of the board. Check diodes, resistors. What are DC voltages before transformer (right side)? I measured 330 V (be careful). AC input: 120V You can disconnect audio board from PSU (5V, 15V+PSON, 62V). You should get only 5V on the left side, but the other side should work OK, except main transformer, because SSC9522S is off (no power on signal)

@Krisztoszteron, did you get 0.2 ohms on those marked pins (picture that I posted) too? Transformer pins connected to ground and R56 resistor. I appreciate if you can measure it for me! About the problem of your PSU, I suggest checking diodes, resistors, capacitors. Try to check and understand the “path” of current from transformers to output.

@Krisztoszteron Yes, the little transformer, for 5V, close to A6069H IC. There is no continuity in this auxiliary coil. Primary coil: 5 ohms Secondary coil: 0.2 ohms I suppose this is the fault… No high Vcc, no power to main IC (controller of higher voltages) The transformer has a code: 042-010317-001ZR I could not find any specification to replace it. I’ll try to desolder and check the transformer.

@DerHouy, thanks! Please share with us when you can. I am still investigating this part of PSU. I am getting 5V (V_out), but Vcc of A6069H is only 9.3V (maybe Vcc bias according to datasheet). This Vcc feeds the main IC of PSU (15V and 62V) when you move the power switch to ON. But undervoltage of this main IC (SSC9522S) is 9.8 V. Thus, no power output. Edit: Resistance at auxiliary winding D is huge (megaohms) and unstable. Did I find the problem? Edit 2: Yes, that was the problem. I removed the transformer and soldered a new wire to the transformer socket. Then the resistance returned to 1.5 ohm and Vcc is around 17 volts. Subwoofer is working properly and now I’m using the 12V trigger from Denon AVR to control the main AC power of the subwoofer (AC outlet).

@DerHouy or anyone, can you measure the voltage at this pin (Vcc, pin 5)? You can use heatsink as ground or the pin 3 of this IC. I got 9.3 V and I suspect it should be higher.

@Roamin Updates: U1 (SSC9522S) controls power mosfet (Q1 on top side) Vcc when PSON=5V: 8.6V Vcc comes from A6069H Vcc (9.3 V), but not directly. What are the expected Vcc voltages for both ICs?

@Roamin, thank you! Here are some pictures of the PSU. Edit: Left side of that white line, where we can see D1, D2, D3 and D4: zero volt Right side: Big capacitors: 165 Vdc Some points: 330 Vdc Big soldering points next to white line, upper side: zero

@Roamin, I don’t have +- 15V and +- 62V. I measured zero volt at the input of -15V regulator. 5V is fine. Can you share any idea where to check more voltages and find a defective component? Thanks!

Update: 7915A regulator (U3): Input: -0,43 V A6069H (U50): Vcc: 9,43 V

Hello, I have a R-115SW unit since 2019. For the last 6 months I left it disconnected (no power cord and no signal cable). Now I turned it on: front LED is on, but no sound (buzz test failed too). I can’t see any burned component. I tried to check some voltages: +5 VDC: OK +-15 VDC: zero +- 62 VDC: zero I disconnected the cables that go to audio pcb. I had read here in this topic about connecting 5V to PSON/OFF: still no +-15V or +-62V (CN2). Edit: different GNDs (15V and 5V connectors), so disconsider this PSON part, because GNDs were not connected. Edit 2: still no 15V or 62V, even with grounds properly connected and PSON = 5V Any suggestion?