And you're sure that you're not heating anything like caps or anything else in the area?
If you're not sure, heat the reg then freeze the caps and other components at the base of the regulator.
If you're not sure, heat the reg then freeze the caps and other components at the base of the regulator.
99% sure. There’s nothing between the regulators and the torrid or maybe 1cm from its base. The cardboard extends from the pcb to 3” above the regulator and opens towards the torrid, hugging the stamped heatsink.
I’ll keep playing with it though.
I’ll keep playing with it though.
Ok… so using just a dmm the negative rail starts at -11.2v cold then warms up to -12.4. The positive rail stays at 13.6-7 warm or cold.
Using the 1.25*(1+R2/R1) rule for the regulators I get a calculated output voltage of 13.75. Negative rail is way off - in practice it may not matter but the noise combined with the hunting voltage seems to point to an issue here.
I was careful not to heat the resistors but it’s possible the board is just conducting heat.
R33 is at about 3% but r34 is close to 8% out, cold. I’m going to start by replacing r34 then maybe the regulator
Using the 1.25*(1+R2/R1) rule for the regulators I get a calculated output voltage of 13.75. Negative rail is way off - in practice it may not matter but the noise combined with the hunting voltage seems to point to an issue here.
I was careful not to heat the resistors but it’s possible the board is just conducting heat.
R33 is at about 3% but r34 is close to 8% out, cold. I’m going to start by replacing r34 then maybe the regulator
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A constant 1.25 between adjust and output tends to mean the regulator is OK but that's not 100%.