Hello,
I built my CP4500 kit, and the first channel is just working fine, but not the second one (PCB B). When I feed the unit with a 2VAC, 1kHZ signal, the max output level i get when the "in" control is engaged si about 1,5VAC at maximum. This level is also not affected by the "thresold" or "makeup gain" controls, contrary to the first channel.
I checked the solder and cleaned the whole PCB in an isopropyl dip since it seems to be a frequent issue. Nothing changed for now. All the ICs seem to be in the good spots and in the right directions.
Here are the results i measured following the troubleshooting procedure .
Channel 2Step..... | Conditions | Result |
1 | Mix = 100% Ratio = 10 Attack = 0.1 Release =1.2 IN button pressed HF lift, 100Hz, 50Hz buttons released Negative meter probe on 0V | - V+ =+15 to +16VDC, +16VDC
- V- =-15 to -16VDC), -16VDC
- +12V = +11.1 to +12.9VDC, don't know where to measure it
- -12V = -11.1 to -12.9VDC same
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2 | Step 1 conditions plus: Input signal = 0V Threshold on +15 Makeup on 0 | TP6, TP7, TP8, TP9 = 0VDC 0VDC |
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3 | input signal = 3VAC Threshold on +15 Makeup on 0 | Signal level (VAC) on
- TP6=1.5VAC, 1.16VAC
- TP7=1.5VAC, 2.02 VAC
- TP8=1.5VAC, 1.16 VAC
- TP9=0.06VAC 1,09 VAC
DC voltage (VDC) on
- pin 1 of U16 (white dot) = 0V. -0.023 VDC
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4 | input signal = 3VAC Threshold on -15 Makeup on +20 | Signal level (VAC) on
- TP6=1.5VAC, 1.16VAC
- TP7=0.4VAC, 2.02 VAC
- TP8=1.5VAC, 1.16 VAC
- TP9=0.2VAC 1.09 VAC
DC voltage (VDC) on
- pin 1 of U16 (white dot) = +0.2V -0.023 VDC
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Thank you guys,