Hi¡
Im working on a kicker cx300.4. It turn on red then green. 4 channels plays audio but its crispy and the volume change every 8 seconds. +-15 volts in the preamp, all checked.
I change the smd cap in the control board, upper left corner, the old one had resistance (270k) and put the amp in red. I try with another tl494, lm358, pulled out ps rail caps, etc and the ps only have +-21v. Im change the irfz46 and the same thing. 4.5v on all gates.
The tl494 have a fluctuation on pin16, not goes to protect, changes between 3 and 4.5 volts. The pin 9 and 10 changes also, so the ps isnt working properly.
With the protection diodes lifted the amps turns on in red.
I try to lift 10k protection resistors on the control area and in the output section near the speaker terminals and same thing. I checked the c945 and 4401 protection circuit transistor all are ok. What voltage is normal at this diodes?
The control board have the diodes and resistors ok.
All output transistor are ok too.
Any ideas?
Im working on a kicker cx300.4. It turn on red then green. 4 channels plays audio but its crispy and the volume change every 8 seconds. +-15 volts in the preamp, all checked.
I change the smd cap in the control board, upper left corner, the old one had resistance (270k) and put the amp in red. I try with another tl494, lm358, pulled out ps rail caps, etc and the ps only have +-21v. Im change the irfz46 and the same thing. 4.5v on all gates.
The tl494 have a fluctuation on pin16, not goes to protect, changes between 3 and 4.5 volts. The pin 9 and 10 changes also, so the ps isnt working properly.
With the protection diodes lifted the amps turns on in red.
I try to lift 10k protection resistors on the control area and in the output section near the speaker terminals and same thing. I checked the c945 and 4401 protection circuit transistor all are ok. What voltage is normal at this diodes?
The control board have the diodes and resistors ok.
All output transistor are ok too.
Any ideas?
It looks like output protection
Lift DP7. If this allows the amp to power up, green light solid, check for DC voltage on the speaker terminals. If none check the output for audio.
With the protection diodes lifted the amps turns on in red.
What are the locator designations for the diodes and the 10K ohm resistors you refer to below?
I try to lift 10k protection resistors on the control area and in the output section near the speaker terminals and same thing. I checked the c945 and 4401 protection circuit transistor all are ok. What voltage is normal at this diodes?
Send good pics of the boards top side and a close up of the control board.
Lift DP7. If this allows the amp to power up, green light solid, check for DC voltage on the speaker terminals. If none check the output for audio.
With the protection diodes lifted the amps turns on in red.
What are the locator designations for the diodes and the 10K ohm resistors you refer to below?
I try to lift 10k protection resistors on the control area and in the output section near the speaker terminals and same thing. I checked the c945 and 4401 protection circuit transistor all are ok. What voltage is normal at this diodes?
Send good pics of the boards top side and a close up of the control board.
I cant find rp87, where is located?? 0 ohms between power and ground??? Why?
No zd nomenclature on control board. No adhesive on ot.
Ray, The zero ohm resistor replaces what in the past would be a low value, high wattage resistor, such as a 1Kohm 1 watt and a capacitor in parallel.
The zero ohm resistor in parallel with CP31-104/c does the same task in shunting any AC component to ground. The resistor shunts any DC component and acts as a fusible link if there is excessive voltage, protecting the board and traces and any components that might be vulnerable. I see this fairly often. This is an educated guess, I would be curious if other amp manufactures use the same method.
The zero ohm resistor in parallel with CP31-104/c does the same task in shunting any AC component to ground. The resistor shunts any DC component and acts as a fusible link if there is excessive voltage, protecting the board and traces and any components that might be vulnerable. I see this fairly often. This is an educated guess, I would be curious if other amp manufactures use the same method.
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