Alright I have a autotek model 44 previously had issues with powering into protect mode. Replaced n4751 @zd1 next to ohm load switch. Switch selects between 1 and 2 ohms. Amp powers up now with input level turned down to lowest level if you turn of all the way up it goes to protect with no speakers or RCA cables connected. Connected RCA cables and a 3 ohm speaker up to channel 1with audio playing. No sound at all but speakers does full excursion in then out then rests. Does repeatedly. Does this on both channels. When speaker is bridged does nothing.
Tested all output fets all test fine.
Tested all output fets all test fine.
if your talking about the output fets.transistors, yes i did. If not, please inform me of what they look like.
thanks
thanks
as you can see the board got kind of "crispy" where the diode i guess it is blew. previous owner said he ran it below 1 ohm maybe even with switch in 2 ohm position. the amp is an autotek 44 revision d.
What's the resistance between the RCA shields and the non-bridging speaker terminals?
If you place the black probe on one of the non-bridging speaker terminals, what is the DC voltage on pins 4 and 11 of the 14-pin op-amps?
With no speakers connected, what's the DC voltage measured directly across the speaker terminals for each channel? Place the black probe on the non-bridging speaker terminal when reading the voltage on both channels.
If you place the black probe on one of the non-bridging speaker terminals, what is the DC voltage on pins 4 and 11 of the 14-pin op-amps?
With no speakers connected, what's the DC voltage measured directly across the speaker terminals for each channel? Place the black probe on the non-bridging speaker terminal when reading the voltage on both channels.
alright, resistance between rca shields and non bridging terminals is .4 on both terminals and both shields, which is the resistance of my probes touching, so 0 ohms.
secondly, i assumed when you said 14 pin op-amps, you meant the 3 14-pin ic chips.
if so then here are the measurements. as labeled on board.
ic-101
pin 4(19.55)
pin 11(11.67)
ic-201
pin4(19.63)
pin11(11.26)
ic-3
pin4(11.45)
pin11(11.09)
lastly w/no speakers connected the dc voltage measured directly across speaker terminals on each channel was
ch.1(.17)
ch.2(.15) fluctuating to (-.20)
If i a wrong about the op amps, please let me know what they look like. thanks
secondly, i assumed when you said 14 pin op-amps, you meant the 3 14-pin ic chips.
if so then here are the measurements. as labeled on board.
ic-101
pin 4(19.55)
pin 11(11.67)
ic-201
pin4(19.63)
pin11(11.26)
ic-3
pin4(11.45)
pin11(11.09)
lastly w/no speakers connected the dc voltage measured directly across speaker terminals on each channel was
ch.1(.17)
ch.2(.15) fluctuating to (-.20)
If i a wrong about the op amps, please let me know what they look like. thanks
Are the RCA shields on the head unit OK (0 ohms to the case of the head unit)?
Is the head unit ground connected to the amp ground?
Is the head unit ground connected to the amp ground?
Well both the radio and amplifier are grounded to vehicle but not on same spot. Rca'a measure fine. I have also hooked up another amplifier in my car and amp worked fine. What's weird is amp goes onto protect when turned up without. Any speakers connected.
yes the amp still does the pulsating to the speaker whether or not it is connected to a sound source or ANY rca's.
also i decided to turn amp up to 3/4 gain with speaker connected. it started making a high pitch to low pitch distorted bass sound.
also i decided to turn amp up to 3/4 gain with speaker connected. it started making a high pitch to low pitch distorted bass sound.
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Do both channels do this?
Do you only have the pulsing voltage across the speaker terminals with a speaker connected?
Do you only have the pulsing voltage across the speaker terminals with a speaker connected?
When the voltage is pulsing on the speaker terminals, do you get the same pulsing (at a much lower level (maybe 1/10th the voltage range) on the output pins of any of the op-amps?
The output pins are the ones on the corners of the 14-pin op-amps.
Does the voltage pulse until the amp is switched off or until it goes into protect?
The output pins are the ones on the corners of the 14-pin op-amps.
Does the voltage pulse until the amp is switched off or until it goes into protect?
There are no fluctuations on the open amps. Once of goes into protect. The voltages basically drop to zero volts
On any of the corner pins of the op-amps, is there any more than about 0.01v DC before it goes into protect?
Was the DC voltage on pin 11 of the op-amps negative or positive with the black probe on the RCA shields?
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