OK, and as for the test points that I suggested, they are the bare copper coils that show in the photos posted back a ways. You will need to either probe at the end of the coil or scrape off a patch of the clear insulation coating to get a good connection.
The voltage at the output of a correctly operating amplifier module is very close to zero once it has stabilized after switch-on.
If you examine the circuit schematic you will see that the coil is connected directly to the module output on pin 12.

Hi
Is it these coils as pictured, getting 22.2v from each one !.

 

Re your readings from post #38. On pins 7 and 8 I assume the two values are from both ends of the resistor. On this assumption all the voltages look OK except for pin 7. Looking at the datasheet for IC601 the capacitor and resistors connected to pin 7 provide a delay at power on to give things time to stabilise before the relay closes and connects the speakers. C603 may have gone short circuit, R605 may have gone open circuit (Unlikely.) or IC601 is faulty. With the speakers NOT connected it should be safe to remove C603 and see if you get the correct voltage (2.2 volts) on pin 7. It may take a second or two after power on the reach the correct level.

Les.

 

Ok, tks for that will do.

cheers
Spike

 

Re your readings from post #38. On pins 7 and 8 I assume the two values are from both ends of the resistor. On this assumption all the voltages look OK except for pin 7. Looking at the datasheet for IC601 the capacitor and resistors connected to pin 7 provide a delay at power on to give things time to stabilise before the relay closes and connects the speakers. C603 may have gone short circuit, R605 may have gone open circuit (Unlikely.) or IC601 is faulty. With the speakers NOT connected it should be safe to remove C603 and see if you get the correct voltage (2.2 volts) on pin 7. It may take a second or two after power on the reach the correct level.

Les.

Hi
Pin 7:
via each side of R605. -144mV then runs down to 20mV and 50mV up to 140mV then back down again, then repeats.
cheers
Spike

 

C310 needs changing !

 

In post #38 you say
7:---10mV and 3.3v ( R605)
8:---3.3v and 47.2v ( R606)
So for R606 The left hand end (On the schematic.) is connected to the +49 volt rail so 47.2 volts is about right. The right hand end is connected to pin 8 so 3.3 volts is correct according to the schematic. This is the same point a the left hand end of R605.
In post #44 you seem to be saying that BOTH ends of R605 are varying between -144 mV and + 140 mV. Is the right hand end of R606 varying in the same way ? (This should be electrically the same point.)
I had noticed that you said in post #33 that C301 was bad but you have not said what was wrong with it. I can't see that this can be related to the protection circuit fault.

Les.

 

In post #38 you say
7:---10mV and 3.3v ( R605)
8:---3.3v and 47.2v ( R606)
So for R606 The left hand end (On the schematic.) is connected to the +49 volt rail so 47.2 volts is about right. The right hand end is connected to pin 8 so 3.3 volts is correct according to the schematic. This is the same point a the left hand end of R605.
In post #44 you seem to be saying that BOTH ends of R605 are varying between -144 mV and + 140 mV. Is the right hand end of R606 varying in the same way ? (This should be electrically the same point.)
I had noticed that you said in post #33 that C301 was bad but you have not said what was wrong with it. I can't see that this can be related to the protection circuit fault.

Les.

Hi
Thanks again for your time n help, will have to re group and check back what I have said .
Regards
Spike

 

In post #38 you say
7:---10mV and 3.3v ( R605)
8:---3.3v and 47.2v ( R606)
So for R606 The left hand end (On the schematic.) is connected to the +49 volt rail so 47.2 volts is about right. The right hand end is connected to pin 8 so 3.3 volts is correct according to the schematic. This is the same point a the left hand end of R605.
In post #44 you seem to be saying that BOTH ends of R605 are varying between -144 mV and + 140 mV. Is the right hand end of R606 varying in the same way ? (This should be electrically the same point.)
I had noticed that you said in post #33 that C301 was bad but you have not said what was wrong with it. I can't see that this can be related to the protection circuit fault.

Les.

Hi Les
The fiures for R606 were given before I removd C603, they are now aroung 30mV building up to around 140mV and back down again then up again for both left - and right side +.
Yes they are the same has R605.
C310 is bulging at the top !.

Ps: C603 seems to be ok .

Spike

 

So are you now saying that you no longer have 47 volts on the left hand end of R606 ?

Les.

 

So are you now saying that you no longer have 47 volts on the left hand end of R606 ?

Les.

+

Yes don't have that figure, since I have removed c03 , they are now what I have just given.
Spike

 

Did you check that you still has about + 49 volts entering the board on connector CN951 pin 1 ? When you find that you do not have a voltage or signal at the point you are testing you need to follow the path back to the source. This is standard fault finding procedure.

Les,

 

So are you now saying that you no longer have 47 volts on the left hand end of R606 ?

Les.

Sorry there was a bad chassis connection at the rear, I didn't screw all the screws back, have also put c 603 back.

So the figures are now as:

R606:: left side 47.2v right side 3.2v
R605: left side 3.3v and right side 17.4mV
Spike

 

Did you check that you still has about + 49 volts entering the board on connector CN951 pin 1 ? When you find that you do not have a voltage or signal at the point you are testing you need to follow the path back to the source. This is standard fault finding procedure.

Les,

Yes have 47.2v at connector CN951
Spike

 

Hi
Yes I know you guys are fed up with me, but here I go again, .pdf doc giving all the readings from IC301 and IC901, could you just have a look for me please ? .
Regards
Spike

 

You seem to be giving two voltage readings for every pin. I am guessing you are giving the readings on BOTH ends of the component that is connected to that pin without telling us which reading is related to the end connected to the pin. If you cant follow the tracks the do a resistance test BUT SWITCH OFF THE POWER AND WAIT UNTIL THE SUPPLY CAPACITORS HAVE DISCHARGED BEFORE DOING THE RESISTANCE TEST.
I assume you have given up on the method of fault finding that I suggested to find out why the speaker relay was not being energised.
There is definitely something as you have 44 volts on pin 12 and the voltages on pins 10 and 11 should be negative NOT positive.

Les.

 

You seem to be giving two voltage readings for every pin. I am guessing you are giving the readings on BOTH ends of the component that is connected to that pin without telling us which reading is related to the end connected to the pin. If you cant follow the tracks the do a resistance test BUT SWITCH OFF THE POWER AND WAIT UNTIL THE SUPPLY CAPACITORS HAVE DISCHARGED BEFORE DOING THE RESISTANCE TEST.
I assume you have given up on the method of fault finding that I suggested to find out why the speaker relay was not being energised.
There is definitely something as you have 44 volts on pin 12 and the voltages on pins 10 and 11 should be negative NOT positive.

Les.

Hi
Thanks for your reply, no I havn't given up on fault finding, there was just too much info in all the replies, I was just getting lost with it all, that is why I have sort of re submitted the info.
Yes will find out which reading is for what pin.
Regards
Spike

 

Hi
Just a note while I get all the info, there is a feed of 47.2v to D601 that feeds the relay, that is there even when the speaker switch is off !.

spike

 

Relay is 24v !

 

There is continuity from pin 6 on the IC 601 to D601 at the relay coil, even when the speaker switch is off !.
Spike

 

The speaker switch is between the output of IC601 (Pin 6) and the other side of the relay. There are also two resistors in series with the relay coil. These are to drop the voltage on the relay coil down from 49 volts to 24 volts. (The relay coil voltage rating.) The relay does not pull in just because there is 49 volts on one end of the coil. There has to be current through the coil for it to pull. So the speaker switch has to be closed AND pin 6 of IC601has to be pulled down close to zero volts for the relay to close. IC601 only pulls pin 6 low when there are no fault conditions in it's inputs AND C603 has been charged up to 2.2 volts. This is done by current by current from the + 49 volt rail through R606 and R605 in series. I am waiting for the results of you removing C603 to see if that has become electrically leaky and shunting that current to ground. You have re fitted that capacitor before testing the voltage on pin 7 properly with the capacitor removed.
I initially assumed you had more experience than you have at repairing electronics. As a result of this wrong assumption I only said to test the voltage on IC301 pin 12 without saying to find a safe point to connect your meter probe if it was difficult to connect directly to pin 12.
Les.