Never run the amp without the current limiter bulb until it is repaired. It should be able to play music at a watt or 5 with the light bulb limiter in circuit.
Don't have a drawing program or a camara. Hot of wall plug goes to circuit breaker. Output of circuit breaker goes to center pin of incandescent (edison) socket. Ring of edison socket goes to hot pin of AC socket on your light bulb box.
Other hot pin from input (europe) goes through breaker directly to other hot pin of AC socket.
Breaker is 2 pole. If don't have a 2 pole 15 A breaker, insert a 2 pole light switch on the breaker side.
Connect metal case of light bulb box to safety pin of wall plug, and to safety pin of load socket. Reason for grounded case, if wire comes loose on the light bulb socket and hits case, it will blow the breaker.
Don't have a drawing program or a camara. Hot of wall plug goes to circuit breaker. Output of circuit breaker goes to center pin of incandescent (edison) socket. Ring of edison socket goes to hot pin of AC socket on your light bulb box.
Other hot pin from input (europe) goes through breaker directly to other hot pin of AC socket.
Breaker is 2 pole. If don't have a 2 pole 15 A breaker, insert a 2 pole light switch on the breaker side.
Connect metal case of light bulb box to safety pin of wall plug, and to safety pin of load socket. Reason for grounded case, if wire comes loose on the light bulb socket and hits case, it will blow the breaker.
I asked - do you own a variac.
We can not know you use essential tools or not.
Edit : I thought it was clear you already use the bulb limiter (post 18).
We can not know you use essential tools or not.
Edit : I thought it was clear you already use the bulb limiter (post 18).
Last edited:
With the amplifier off, have you tried measuring across the output devices (Q329, Q331, Q332 etc from the schematic I see), with resistance/diode check on a multi-meter (between collect/emitter or all pins), to check for short circuits on the output stage?
While shopping, don't forget a strain relief or conduit cord fitting for the power cord. If rubber cord insulation passes through the wall of a metal box, the metal could rub the insulation off and cause a short.
I used a salvage box from a 3 phase 480 v motor drive for my light bulb box. Already had the cord fitting and the power switch. Some circuit breakers can double as a power switch (with the toggle lever), but not the push in ones.
All transistors are ok.
I don't understand why the red led no light on
Can i test this led,what voltage?
I don't understand why the red led no light on
Can i test this led,what voltage?
disconnect torodial on secundary side and check whether the fuse blown again. If yes, transformer shorting - is to replace
Why don't you test the steel case to see if it is broken somewhere?
Data on LED is on wikipedia.
Data on LED is on wikipedia.
The red led is dead,the green led is ok.
Now I understand the amplifier is in Protect mode without red led because her death.
I desoldered all output transistors and now the amplifier power on relay clicks and the green led light up.
The fuse F501 ok.
I will replaced bad output transistors
Now I understand the amplifier is in Protect mode without red led because her death.
I desoldered all output transistors and now the amplifier power on relay clicks and the green led light up.
The fuse F501 ok.
I will replaced bad output transistors
Last edited:
Frequently bad output transistors take out devices ahead of them, and around them. Like the drivers (q326 etc) & the VI limiter? Q338.
You can tell things about them by voltage checks while the worst of the down stream parts are removed (like output transistors) and the power supply is limited in energy by the light bulb in series with the AC input of the transformer.
As for example, 9 v across led is improbable. Correct red LED voltage is ~1.4. How ever, some manufactures install "LED"s with also an internal resistor, which may have any voltage across it lit up, usually 5 or 12. These are more properly called "lamps" but such precision in nomenclature can't be expected.
You can tell things about them by voltage checks while the worst of the down stream parts are removed (like output transistors) and the power supply is limited in energy by the light bulb in series with the AC input of the transformer.
As for example, 9 v across led is improbable. Correct red LED voltage is ~1.4. How ever, some manufactures install "LED"s with also an internal resistor, which may have any voltage across it lit up, usually 5 or 12. These are more properly called "lamps" but such precision in nomenclature can't be expected.
Last edited: