Were the RCA shields connected to chassis ground when you were measuring the voltage on the amp?
The Z48v will work in place of the N version.
The power supply FETs will have no effect on the regulated voltage.
You stated earlier that you had 12v on pin 14 of IC703. Unless I followed the wrong circuit. It appears that Q604 (8v reg) supplies voltage to pin 14 of IC703. Is this not correct (confirm with ohm meter)?
The Z48v will work in place of the N version.
The power supply FETs will have no effect on the regulated voltage.
You stated earlier that you had 12v on pin 14 of IC703. Unless I followed the wrong circuit. It appears that Q604 (8v reg) supplies voltage to pin 14 of IC703. Is this not correct (confirm with ohm meter)?
I had them grounded when measuring the 2nd ground
indication circuit..when checking the regulated voltage i didnt
had them grounded-
I can confirm that IC703 pin 14 is directly connected to Q604
wich has excatly 8 volts out....
Have to measure the voltage on IC702 again...strange
last time i measured i had 12volts with a small pulse.
About the +-15volt reg circuit...its taking voltage directly
after the rectifyer and feeding into the regulator circuit(15volts)
And IC702 (the battery indicator IC)
takes the supply voltage from this +-15Reg..
And its not giving me +-15Volts :S
Measured it to +17,5 and -13,3 wich in my eyes isnt good.
I am going to take a sleep now
just find more and more to dig in, and its not good to fault finding several things simultanius =)
indication circuit..when checking the regulated voltage i didnt
had them grounded-
I can confirm that IC703 pin 14 is directly connected to Q604
wich has excatly 8 volts out....
Have to measure the voltage on IC702 again...strange
last time i measured i had 12volts with a small pulse.
About the +-15volt reg circuit...its taking voltage directly
after the rectifyer and feeding into the regulator circuit(15volts)
And IC702 (the battery indicator IC)
takes the supply voltage from this +-15Reg..
And its not giving me +-15Volts :S
Measured it to +17,5 and -13,3 wich in my eyes isnt good.
I am going to take a sleep now
just find more and more to dig in, and its not good to fault finding several things simultanius =)after replacing some pow-fets i measured the
regulated voltage with black lead on rca ground.
Perfekt!
takes a week for my local shop to get me another DTA144EK
and if i order from digikey.com ord mouser they take 50$!!!!
in shipping flat rate... no way... whatg should i do
is it possible to just take a transistor from my junk boxes
and bias it with two 47k resistors as the DTA144 is biased?
or is it just a stupid idea :S
Cant measure the voltages untill i have the componet in
circuit i guess :S
regulated voltage with black lead on rca ground.
Perfekt!
takes a week for my local shop to get me another DTA144EK
and if i order from digikey.com ord mouser they take 50$!!!!
in shipping
flat rate... no way... whatg should i dois it possible to just take a transistor from my junk boxes
and bias it with two 47k resistors as the DTA144 is biased?
or is it just a stupid idea :S
Cant measure the voltages untill i have the componet in
circuit i guess :S
IC702
1 -13.6
2 5.3
3 6
4 -15
5 0.28
6 14,3
7 14,3
8 14,9
SHOULD BE
(15,5)
(4,67)
(7,1)
(-15,8)
(1,8)
(1,5mV)
(1,8)
(15,9)
IC703
1 0-10v pulsing
2 0.2
3 0.3
4 0-10v pulsing
5 0-10v pulsing
6 9.4p
7 0.3
8 11.5
9 0.28
10 0-10v pulsing
11 0.3
12 0.3
13 0-10v pulsing
14 0.3
SHOULD BE
pin1 1
pin2 7.4
pin3 1
pin4 1.7mV
pin5 1
pin6 15.5mV
pin7 1.6mV
pin8 11mV
pin9 1.7mV
pin10 1.7mV
pin11 1.8mV
pin12 1
pin13 1.6mV
pin14 8V
Very strange readings, what the hell??? have all ICs gone wacked? :S
The 8 volt supply is ok ive checked it!
and the +-15 volt reg is OK... what is happening here
1 -13.6
2 5.3
3 6
4 -15
5 0.28
6 14,3
7 14,3
8 14,9
SHOULD BE
(15,5)
(4,67)
(7,1)
(-15,8)
(1,8)
(1,5mV)
(1,8)
(15,9)
IC703
1 0-10v pulsing
2 0.2
3 0.3
4 0-10v pulsing
5 0-10v pulsing
6 9.4p
7 0.3
8 11.5
9 0.28
10 0-10v pulsing
11 0.3
12 0.3
13 0-10v pulsing
14 0.3
SHOULD BE
pin1 1
pin2 7.4
pin3 1
pin4 1.7mV
pin5 1
pin6 15.5mV
pin7 1.6mV
pin8 11mV
pin9 1.7mV
pin10 1.7mV
pin11 1.8mV
pin12 1
pin13 1.6mV
pin14 8V
Very strange readings, what the hell??? have all ICs gone wacked? :S
The 8 volt supply is ok ive checked it!
and the +-15 volt reg is OK... what is happening here
You have to be careful of the reference you use. If you leave the RCA shield grounded, you can use either the chassis ground or the shield as the reference. I'd suggest that you connect the shield to the chassis ground for all future measurements.
What is the voltage across ZD601 (black lead on anode)?
What is the voltage from the anode of ZD601 (black lead) to the emitter of Q604?
Is the voltage between the anode of ZD601 and chassis ground 0v.
What is the voltage across ZD601 (black lead on anode)?
What is the voltage from the anode of ZD601 (black lead) to the emitter of Q604?
Is the voltage between the anode of ZD601 and chassis ground 0v.
You have to be careful of the reference you use. If you leave the RCA shield grounded, you can use either the chassis ground or the shield as the reference. I'd suggest that you connect the shield to the chassis ground for all future measurements.
---Ok then i will !
What is the voltage across ZD601 (black lead on anode)?
---Voltage across ZD601 = 8.75V
What is the voltage from the anode of ZD601 (black lead) to the emitter of Q604?
---Voltage from anode ZD601 to emitter (leg 1...) of Q604 = 8.12
(someone have resolderd this before, donnow why...)
Is the voltage between the anode of ZD601 and chassis ground 0v.
---Voltage from anode ZD601 ---->>> chassie with black lead on RCA ground (still with chassie ground tiead to RCA shields = 0.82
Isnt that strange ? =)
---Ok then i will !
What is the voltage across ZD601 (black lead on anode)?
---Voltage across ZD601 = 8.75V
What is the voltage from the anode of ZD601 (black lead) to the emitter of Q604?
---Voltage from anode ZD601 to emitter (leg 1...) of Q604 = 8.12
(someone have resolderd this before, donnow why...)
Is the voltage between the anode of ZD601 and chassis ground 0v.
---Voltage from anode ZD601 ---->>> chassie with black lead on RCA ground (still with chassie ground tiead to RCA shields = 0.82
Isnt that strange ? =)
The regulator components appear to be OK. There may be a bad solder joint between the chassis ground and the anode of ZD601. Desolder and resolder all of the connections on Q604 and D601. If you still read nearly 0.9v, you need to determine why. There shouldn't be more than 0.1v. Ideally, there would be a 0.0v difference. The 0.82 difference probably isn't a real problem but it could indicate that there's a bad connection somewhere which could cause intermittent problems. I'm assuming that you still read 0v between the RCA and chassis grounds.
Hello Perry!
Now i have replaced ALL caps on the power supply board!
And i cleaned the "soldering" side gentle with some topz
and flux off as good as i could between components
and around the ICs.
Did the same thing on the "component" side. Was a lot of
"dust" on the board around the cooling fan and dust had
stuck between components (just a layer of dust...)
Not like dust balls whatever...
Now i have a reading of 0.002V if i place a lead on the Zener
and to ground (still with RCA ground connected to chassi)
Strange thing is that IC701 pin4 (is connected After ic 703)
here i have exactly 8Volts!!! Rock steady...
On IC703 pin 14 i still got around 11 volts with a small pulsing
around 10,8 and 11 volts..... the same frequensy as the LEDs flashing.
A very strange thing is if i place one lead on pin 4 of IC701
and the second on IC703 i get some wierd ohm reading.
Can i say from this that IC703 is leaking internally?
There would be nice if i could remove it without destroying the IC.
6 legs on each side :S Any tips of how to remove it with a ordinary
soldering iron? I have two of them if needed, even 3
But not 6 of them!!
If i could remove it then i could measure pin 14 without the IC
in place to see if i have 8Volts....
Now i have replaced ALL caps on the power supply board!
And i cleaned the "soldering" side gentle with some topz
and flux off as good as i could between components
and around the ICs.
Did the same thing on the "component" side. Was a lot of
"dust" on the board around the cooling fan and dust had
stuck between components (just a layer of dust...)
Not like dust balls
whatever...Now i have a reading of 0.002V if i place a lead on the Zener
and to ground (still with RCA ground connected to chassi)
Strange thing is that IC701 pin4 (is connected After ic 703)
here i have exactly 8Volts!!! Rock steady...
On IC703 pin 14 i still got around 11 volts with a small pulsing
around 10,8 and 11 volts..... the same frequensy as the LEDs flashing.
A very strange thing is if i place one lead on pin 4 of IC701
and the second on IC703 i get some wierd ohm reading.
Can i say from this that IC703 is leaking internally?
There would be nice if i could remove it without destroying the IC.
6 legs on each side :S Any tips of how to remove it with a ordinary
soldering iron? I have two of them if needed, even 3
But not 6 of them!!
If i could remove it then i could measure pin 14 without the IC
in place to see if i have 8Volts....
I followed the regulated 8Volts right from Q604 and forward
all the way to the last bit in the chain, IC701
looks like this.
Q604 8V (8volt regulator)
E606 8V <--positive leg...
Q811 8V
Q808 8V
Q815 8V
Q817 8V
Q705 10V very small pulse, visible on scope and DMM
Q721 10V very small pulse, visible on scope and DMM
IC703 (removed) "pad 14" 10V very small pulse, visible on scope and DMM
Q701 8V very small pulse
IC701 pin 4 (Vcc) 8V very very small pulse
Then at last i completly removed Q705 and Q721(removed this before)
And now the pulse dissapeard, still 10 volts on IC703.....pin14
seem like Q705 and Q721 draging enough current when "blinking" to create a voltage drop
visible on the scope and nearly not visible on multimeter.
Its still a mystery to me why i have 10 volts on IC703 pin 14...
Have cleaned the board with cotton topz and flux-off PCB Cleaner
around the SMDs.
MAYBE? Maybe its doesnt matter that ill have 10 volts on
pin 14 of IC703...and the small pulse...does it matter?
Its not in the audio path anyway...
Perry, say something or anyone, have a look at this.
Been working hard on this amp all night!
all the way to the last bit in the chain, IC701
looks like this.
Q604 8V (8volt regulator)
E606 8V <--positive leg...
Q811 8V
Q808 8V
Q815 8V
Q817 8V
Q705 10V very small pulse, visible on scope and DMM
Q721 10V very small pulse, visible on scope and DMM
IC703 (removed) "pad 14" 10V very small pulse, visible on scope and DMM
Q701 8V very small pulse
IC701 pin 4 (Vcc) 8V very very small pulse
Then at last i completly removed Q705 and Q721(removed this before)
And now the pulse dissapeard, still 10 volts on IC703.....pin14
seem like Q705 and Q721 draging enough current when "blinking" to create a voltage drop
visible on the scope and nearly not visible on multimeter.
Its still a mystery to me why i have 10 volts on IC703 pin 14...
Have cleaned the board with cotton topz and flux-off PCB Cleaner
around the SMDs.
MAYBE? Maybe its doesnt matter that ill have 10 volts on
pin 14 of IC703...and the small pulse...does it matter?
Its not in the audio path anyway...
Perry, say something
or anyone, have a look at this.Been working hard on this amp all night!
R717 R714 why do they have i direct connection???
They are not connected to each other on schematic
from what i can see...
They are placed just next to each other, tought
there was a solder bridge between them.
But after removing the solder it seem like there is a trace.
Because if there was not one of the pads lead NOWHERE.
There was no ohm from pin 14 IC703 to Q604 (8V)
BUT there is 565 ohm from pin 4 IC702 to 8V :S
This is getting more and more wierd =)
Been following traces all night, the go under SMD devices and
ICs and criss-cross my eyes are not happy
Have to continue tomorrow, cant get why the resistors are
connected tought, cant see that on schematic.
And the component layout are crappy in service manual.
Very poor quality, cant se the traces....
They are not connected to each other on schematic
from what i can see...
They are placed just next to each other, tought
there was a solder bridge between them.
But after removing the solder it seem like there is a trace.
Because if there was not one of the pads lead NOWHERE.
There was no ohm from pin 14 IC703 to Q604 (8V)
BUT there is 565 ohm from pin 4 IC702 to 8V :S
This is getting more and more wierd =)
Been following traces all night, the go under SMD devices and
ICs and criss-cross my eyes are not happy
Have to continue tomorrow, cant get why the resistors are
connected tought, cant see that on schematic.
And the component layout are crappy in service manual.
Very poor quality, cant se the traces....
i am completly sure, dubblechecked.
And if they was not connected, then one of the
pads have nowhere to go.
have to check one more time after work.
after removing some resistors i now have 8 volts on pin 14...
very strange its hard to se the traces also.
had to remove several SMD resistors...
some glue underneath that i cant remove.
And if they was not connected, then one of the
pads have nowhere to go.
have to check one more time after work.
after removing some resistors i now have 8 volts on pin 14...
very strange
its hard to se the traces also.had to remove several SMD resistors...
some glue underneath that i cant remove.
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