This amp powers up and plays but both channels have very distorted audio and the low impedance light is on along with the power light ..
Anyone have any ideas
Anyone have any ideas
Are you sure that it doesn't have any shorted output transistors or out of tolerance emitter resistors?
Does it have ± rail voltage?
Does it have ± regulated voltage at the op-amps?
How much current is it drawing?
Does the low impedance LED light up with no speakers connected?
Does it have ± rail voltage?
Does it have ± regulated voltage at the op-amps?
How much current is it drawing?
Does the low impedance LED light up with no speakers connected?
It only draws about 1 amp of current
All resistors are within tolerance
No outputs shorted at all
I think I found the problem I'm not getting any rail voltages
I do not get positive or negative rail voltages ..
Any ideas on what to check ?
I get regulated voltages + - 15 volts just no rail voltages
All resistors are within tolerance
No outputs shorted at all
I think I found the problem I'm not getting any rail voltages
I do not get positive or negative rail voltages ..
Any ideas on what to check ?
I get regulated voltages + - 15 volts just no rail voltages
The legs are intact I try gently pushing on them back and fourth and wiggling them .. Legs are intact and soldered to the board just get no rail voltage
I only get 0.51 volts on all of the rectifiers ..
Not sure if the power supply is working ..
On the gate legs of the power supply gets I only get 0.22 volts isn't it suppose to be around 5 volts ? And if so where is a good place to start
Not sure if the power supply is working ..
On the gate legs of the power supply gets I only get 0.22 volts isn't it suppose to be around 5 volts ? And if so where is a good place to start
Which revision a600 is this?
The power supply is regulated so the gate voltage may read less than an un-regulated supply.
The power supply is regulated so the gate voltage may read less than an un-regulated supply.
The left leg of CR2 and 4 should read 0 ohms to the center leg of all of the 6488 outputs.
The right leg of the other 2 rectifiers should read 0 ohms to the center legs of all of the 6491 outputs.
If one doesn't read 0 ohms, you may have a broken leg or solder connection on the power supply filter inductor.
By chance, one of these came in for repair a few days ago.
The right leg of the other 2 rectifiers should read 0 ohms to the center legs of all of the 6491 outputs.
If one doesn't read 0 ohms, you may have a broken leg or solder connection on the power supply filter inductor.
By chance, one of these came in for repair a few days ago.
Check again while twisting the inductor.
Did you check for DC on the rectifiers on both legs?
Do you read any rail voltage if you measure from the tab of the 6488 to the tab of the 6491?
Did you check for DC on the rectifiers on both legs?
Do you read any rail voltage if you measure from the tab of the 6488 to the tab of the 6491?
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Twisting the inductor makes no difference I still get 0.04 ohms to center legs ..
With black probe on tab of 2n6491 and red probe on tab of the 2n6488 I only get 2.00 volts of rail
With black probe on tab of 2n6491 and red probe on tab of the 2n6488 I only get 2.00 volts of rail
The transformer output feeds both the rail rectifiers and the regulated supply rectifiers. If you have a good regulated supply, that should mean that the supply is operating.
Are you sure that the regulated supply is holding it's voltage, even if the amp is left on for more than a few seconds?
Are you sure that the regulated supply is holding it's voltage, even if the amp is left on for more than a few seconds?
The positive regulated voltage drops then climbs back up to +15 volts and cycles The negative regulated voltage remains at -14.89 volts..
So the supply isn't working correctly any thoughts on where to start looking ?
So the supply isn't working correctly any thoughts on where to start looking ?
SG3525A
Pin 1:2.61
Pin 2:2.60
Pin 3:0.01
Pin 4:0.15
Pin 5:2.08
Pin 6:3.75
Pin 7:2.07
Pin 8:4.93
Pin 9:0.55
Pin 10:0.00
Pin 11::0.04
Pin 12:0.00
Pin 13:12.10
Pin 14:0.03
Pin 15:12.10
Pin 16:5.20
Non of the pins have pulsing voltages they all stay consistant
Pin 1:2.61
Pin 2:2.60
Pin 3:0.01
Pin 4:0.15
Pin 5:2.08
Pin 6:3.75
Pin 7:2.07
Pin 8:4.93
Pin 9:0.55
Pin 10:0.00
Pin 11::0.04
Pin 12:0.00
Pin 13:12.10
Pin 14:0.03
Pin 15:12.10
Pin 16:5.20
Non of the pins have pulsing voltages they all stay consistant
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