My genelec 1031A pops when I turn it on ?

Description: All of the above would be internal hardware issues. Still, there is a possible fix, though it is not quick or easy and there is no workaround. The unit would need to be opened for visual inspection, voltage measurements, confirmation of faults, and subsequent repairs. Are you considering a DIY (do-it-yourself) repair approach? Are you familiar with electronic components, and do you have access to or feel comfortable using a multimeter and perhaps a soldering iron or hot-air station? After reviewing the schematics and service manual, likely suspects would be the muting circuitry that activates when turning the amplifier on or off. Both transistors are connected to the audio feed line; T101 for the tweeter amplifier and T102 for the woofer amplifier. Upon turning on, there is a momentary small voltage at the base of both transistors. This "spike" causes the collector-emitter to conduct. The collectors are connected to ground, which temporarily grounds the audio feed line. Consequently, the "pop" is not amplified and is not heard through the tweeter or woofer. If a "pop" is heard from the woofer, then T102 is not momentarily activating when the Genelec is powered on. The only voltage that can be measured would be at the base when the speaker is being turned on, supplied through resistor R126 from the collector of T12. Although no speakers would not affect voltage measurements, it is preferable to have them connected to apply a load on the amplifiers. Using low-ohm/high-wattage resistors is also an option. If both the tweeter and woofer exhibit the same issue and voltage is measured at the base of the transistor, the focus would return to the T12 circuitry. The simplest method to check capacitors for leaks is with an analog multimeter set to the X10 or X100 scale. Testing the capacitor should cause the needle to deflect to the right and then return to the left position. If it is leaky, the needle will slowly swing back towards the right after returning to the rest position. Good capacitors will not move after the initial deflection. For T101 and T102, the base-to-emitter and base-to-collector should test like diodes, with a forward bias of around 5-10 ohms, while there should be no resistance or continuity from collector to emitter. The same test should be performed on the three diodes, D10, D11, and D12, with particular attention to D11. Each diode should be tested with at least one leg desoldered or lifted. Similar to the base-to-emitter and base-to-collector tests, the diode should show a reading in one direction but not the other. After testing, reassemble all components, including soldering back the diodes, transistors, capacitors, and any other components that were desoldered. Determine if the unit still produces a "pop" when first turned on while observing and measuring the voltage at the collector of T12. Caution is advised, as the unit will be plugged in and therefore live. The highest voltage supplied to the circuitry is +15V. There is no source for 37V with reference to ground. It is suggested to try again; however, it has been noted that the bump has disappeared, and while the power light on the front of the speaker comes on (the red overload light does not—it used to), there is no sound when music is played. Refer to the schematics above. As previously mentioned, before R51 should be a negative voltage, -15V. Before R51 is connected to pin 1 of IC5. If pin 1 of IC5 is -15, then resistor R51 should also have -15 (not ". before R51; 2. 67."). With the unit unplugged, measure continuity from pin 1 of IC5 to the leg before R51. It is likely that the output transistors are affecting the readings of T2, T3, T7, and T8. Desolder or remove these components, taking care to remember which transistor goes where and which pin/leg corresponds to which hole. Alternatively, check for infinity or very high readings. The basic test is from base to emitter.

The described circuit involves a multi-stage amplifier system, where specific transistors (T101 and T102) play crucial roles in managing the audio signal and preventing unwanted noise during power transitions. The muting circuitry is designed to engage briefly at startup, creating a momentary grounding of the audio path to eliminate pops or clicks that could be audible through the speakers.

The transistors' operation can be verified through basic diode testing techniques, ensuring that they function correctly in both forward and reverse bias conditions. Capacitors in the circuit must also be inspected for leakage, as this can significantly impact performance. The use of an analog multimeter is recommended for these tests due to its sensitivity in detecting leakage currents.

Furthermore, the presence of a negative voltage at specific points in the circuit, such as before R51 and at pin 1 of IC5, is critical for proper operation. This suggests that the power supply circuit is functioning correctly and providing the necessary voltages to the amplifier stages.

It is essential to handle all components with care during testing and reassembly, ensuring that any desoldered components are returned to their original positions to maintain circuit integrity. The overall troubleshooting process should be methodical, checking each component's functionality and ensuring continuity throughout the circuit to isolate and repair the fault effectively.All of the above would be internal hardware issuesa. Still, there is a possible fix; though not quick-n-easy and neither is there a workaround. The unit would have to be opened up for visual inspection, voltage measurements, confirm fault and effect repairs. Offhand, are you then considering a DIY (do-it-yourself) repair approach Are you familiar with electronic components, have access to / comfortable in the use of a multimeter and perhaps even a soldering iron/hot-air station Offhand and after a review of the schematics/Service Manual, likely suspects would be muting circuitry that kicks in when turning the amplifier on or off as described below. Both transistors are tied to the audio feed line; T101 for the tweeter amp and T102 for the woofer amp.

On turning on, there is a momentary small voltage on the base of both transistors. This "spike" makes the collector-emitter conduct. The collectors are tied to the ground. What happens then is that the audio feedline is temporarily grounded. The "pop" is then not amplified hence not heard on the tweeter nor the woofer. If there is a"pop" heard on the woofer, then T102 is not momentarily acting when the Genelec is turned on. The only voltage that may be measured would be on the base when the speaker is being turned on. It is supplied through resistor R126 as supplied by the collector of T12. No speakers would not affect the voltage measurements but it would be preferable that they be connected so as to put a load on the amps.

Or even consider using low © / high wattage resistors That it is likely that both tweeter and woofer have the same issue and that there was voltage measured at the base of the transistor, then it would be back to the T12 circuitry. The simplest approach to check capacitor for leaks would be with the use of an analog multimeter set to © X 10 or X 100.

Test the capacitor - the needle would deflect (right) and go back to rest (left) position. If it is leaky, the needle after going back to the rest position would slowly swing back towards the right. Good capacitors would no longer move after the initial deflection. For the T101 & 102, the base to emitter and base to collector would test like a diode. The forward bias would be around 5~10 © while there should be no resistance/continuity from collector to emitter.

Please do the same to the 3 diodes; D10, 11 and 12 with particular attention to D11. Do the test with at least 1 leg of the diode de-soldered/lifted. Just like the base-to-emitter and base-to-collector, the diode would have a reading one-way but not the other. Please assemble everything as they normally are; i. e. solder back in the diodes, transistors, capacitors and whatever components that may have been de-soldered.

Determine if it will still pop when first turned on while observing/measuring the voltage at the collector of T12. Again, please exercise care and caution, the unit would be plugged in and therefore LIVE! Incidentally, the highest voltage supplied to the circuitry is +15V. With reference to ground, there is no source for the 37V. Would it be possible to give it a try again HOWEVER MY BUMP HAS DISSAPEARED BUT WHILE THE POWER LIGHT COMES ON ON THE FRONT OF THE SPEAKER (THE RED OVERLOAD LIGHT DOESNT-IT USED TO ) I HAVE NO SOUND WHEN I APPLY MUSIC.

Please reference the schematics above. And as earlier posted, ". Before R51 should be a negative voltage, -15V. " Before R51 is tied to pin 1 of IC5. If pin 1 of IC5 is -15, then the resistor R51 should also have a -15 (not ". before R51; 2. 67. "). With the unit unplugged, please measure the continuity from pin 1 of IC5 to the before leg of R51. Likely that the output transistors are affecting the readings of T2, 3, 7 & 8. Desolder/remove and please please remember which transistor goes where and equally important, which pin/leg to which hole. Or the other way around where is infinity or UL or very very high reading. The basic is B to E