TP401 measurements seemed normal, but I included the test for reference only.

Here


TP501 + to Qxxx E tests:
Q507 E - tests the connenction
Q509 E - tests R547 and R549
Q515 E - tests R547 and R569
Q517 E - tests R547 and R571

TP501 - to Qxxx E tests:
Q507 E - tests R549 and R549
Q509 E - tests the connenction
Q515 E - tests R549 and R569
Q517 E - tests R549 and R571

TP401 L + to - tests R449 and R451 (4.4 ohms total)
TP401 R + to - tests R450 and R452 (4.4 ohms total)

 

That means that R548 went open between post #508 and #525.
I am a bit suspicious. These are ceramic 0.22Ω 2W.

I think there is more than meets the eye.

Talking about post #508 you are talking about the 0 ohm readings?

I believe i made a blunder there,reffering to 0 ohm as «nothing» when what i really meant was open circuit.... the other 1.5 ohm reading was because of my mini grabbers error. Sorry for the confusion

 

Talking about post #508 you are talking about the 0 ohm readings?

I believe i made a blunder there,reffering to 0 ohm as «nothing» when what i really meant was open circuit.... the other 1.5 ohm reading was because of my mini grabbers error

No. I am well aware of what you have been doing, I think.
I accept your reading of 1.5 ohms. This meant that the resistors were still good.
Now your readings are saying that the resistors are bad.

We are looking at R 548 and R550 for now.

You will have to check Q508, Q510, Q516, Q518.
Check resistors R548, R550, R570, R572. All should be 0.22 ohms.

 

TP401 measurements seemed normal, but I included the test for reference only.

Here


TP501 + to Qxxx E tests:
Q507 E - tests the connenction
Q509 E - tests R547 and R549
Q515 E - tests R547 and R569
Q517 E - tests R547 and R571

TP501 - to Qxxx E tests:
Q507 E - tests R549 and R549
Q509 E - tests the connenction
Q515 E - tests R549 and R569
Q517 E - tests R549 and R571

TP401 L + to - tests R449 and R451 (4.4 ohms total)
TP401 R + to - tests R450 and R452 (4.4 ohms total)

okey, some measurements again

TP501+ to Q507E: 0 ohm
TP501+ to Q509E: open circuit
TP501+ to Q515E: open circuit
TP501+ to Q517E: open circuit

TP501- to Q507E: open circuit
TP501- to Q509E: 0 ohm
TP501- to Q515E: open circuit
TP501- to Q517E: 0.6 ohm

TP401L : 4.8 ohm
TP401R: open circuit

R547: open
R549: 0.3 ohm
R571: 0.3 ohm
R569: open
R450: open
R449: 2.2 ohm
R452: 2.2 ohm
R451: 2.4 ohm

 

Let us assume at Q508 and R548 were both open to start.
This would satisfy the readings at post #491 because TP502 + is floating.

But wait, allow me to confirm the connection at TP502 + and -.
This is something you can double check.

Is TP502 + connected to Q508 E?
Is TP502 - connected to Q510 E?

Or are the markings reversed?

 

No. I am well aware of what you have been doing, I think.
I accept your reading of 1.5 ohms. This meant that the resistors were still good.
Now your readings are saying that the resistors are bad.

We are looking at R 548 and R550 for now.

You will have to check Q508, Q510, Q516, Q518.
Check resistors R548, R550, R570, R572. All should be 0.22 ohms.

hmmm...okey

i measured those resistors in #535
R548: open circuit
R550: 0.3 Ohm
R570: open circuit
R572: 0.3 Ohm


I can check the transistors.... should i take them out of circuit ?

 

Let us assume at Q508 and R548 were both open to start.
This would satisfy the readings at post #491 because TP502 + is floating.

But wait, allow me to confirm the connection at TP502 + and -.
This is something you can double check.

Is TP502 + connected to Q508 E?
Is TP502 - connected to Q510 E?

Or are the markings reversed?

Just checked now,
TP502+ to Q508 reads: 0 ohm, connected
TP502- to Q510E reads 0 ohm, connected

So then the markings are correct? Have i been writing something wrong earlier might

 

So then the markings are correct? Have i been writing something wrong earlier might

That is why we take good notes .... to try and prevent such things.

So with those few tests we discovered a number of resistors OPEN and maybe R451 is out of tolerance,

R547: open (Q507)
R569: open (Q515)
R450: open (Q428)
R548: open (Q508)
R570: open (Q516)

R451: 2.4 ohm (Q427) ... can you read the color bands on that resistor .... all I know is it's a quarter watt but I suspect it also is a 2 % resistor or 5% .... which would make it out of tolerance.

Good work ....

The associated transistors (in parenthesis) should be checked before ordering or seeing if you have some good ones in inventory.

Do you have an oscilloscope or access to one? Do you have a signal generator or access to one?

 

I looked at TP502. As far as I can tell looking at a not too sharp photo of the solder side. TP502 + also labeled 1 is connected to Q510.
TP502 - also labeled 2 is connected to Q508.

This matches the resistance readings in post #508.
Meter at 200.
Measured:
TP502 + to Q508 E : 1.5 Ohm
TP502 + to Q510 E : 0 ohm
TP502 - to Q508 E : 0 Ohm
TP502 - to Q510 E 1.5 Ohm




Here are your results from post #525
Meter at 200 ohm setting, checked the probe value first: 0Ω
Not using mini grabbers.

TP502 + TO Q508: 0Ω
TP502 + to Q510E: open circuit
TP502 - TO Q508E: open circuit
TP502 - TO Q510E: 0Ω

And post #530
okey!
Measured.. i only get open circuit except at Q518.... not 0.44 ohms...

TP502 + to Qxxx E tests the following:
Q508 E ... Tests the connection between the + and the emitter : 0 ohms
Q510 E ... Tests R548 and R550 : open circuit
Q516 E ... Tests R548 and R570 : open circuit
Q518 E ... Tests R548 and R572 : open circuit

TP502- to Qxxx E tests the following
Q508 E ... tests R550 and R548 : open circuit
Q510 E ... tests the connection between the - and the emitter : 0 ohms
Q516 E ... tests R550 and R570 : open circuit
Q518 E ... tests R550 and R572 : 0,6 Ohms

Again at post #547
Just checked now,
TP502+ to Q508 reads: 0 ohm, connected
TP502- to Q510E reads 0 ohm, connected

Are you certain that you are reading the + and - at TP502 correctly?
TP502 pin-1 has the + sign closest to it.

 

Mr Chips,

Here is an earlier photo that may show the run .... from TP502-1(+) to Q508. It looks like the trace goes towards the edge of the board and over to the Transistor. We may need a better picture to confirm.

 

I looked at TP502. As far as I can tell looking at a not too sharp photo of the solder side. TP502 + also labeled 1 is connected to Q510.
TP502 - also labeled 2 is connected to Q508.

This matches the resistance readings in post #508.
Meter at 200.
Measured:
TP502 + to Q508 E : 1.5 Ohm
TP502 + to Q510 E : 0 ohm
TP502 - to Q508 E : 0 Ohm
TP502 - to Q510 E 1.5 Ohm

View attachment 206057


Here are your results from post #525
Meter at 200 ohm setting, checked the probe value first: 0Ω
Not using mini grabbers.

TP502 + TO Q508: 0Ω
TP502 + to Q510E: open circuit
TP502 - TO Q508E: open circuit
TP502 - TO Q510E: 0Ω

And post #530
okey!
Measured.. i only get open circuit except at Q518.... not 0.44 ohms...

TP502 + to Qxxx E tests the following:
Q508 E ... Tests the connection between the + and the emitter : 0 ohms
Q510 E ... Tests R548 and R550 : open circuit
Q516 E ... Tests R548 and R570 : open circuit
Q518 E ... Tests R548 and R572 : open circuit

TP502- to Qxxx E tests the following
Q508 E ... tests R550 and R548 : open circuit
Q510 E ... tests the connection between the - and the emitter : 0 ohms
Q516 E ... tests R550 and R570 : open circuit
Q518 E ... tests R550 and R572 : 0,6 Ohms

Again at post #547
Just checked now,
TP502+ to Q508 reads: 0 ohm, connected
TP502- to Q510E reads 0 ohm, connected

Are you certain that you are reading the + and - at TP502 correctly?
TP502 pin-1 has the + sign closest to it.

Yes, i am reading pin-1 as + at TP502

As i wrote earlier, pretty certain i was not thinking straight in post #508 and wrote 0 ohm instead of open circuit
post #508 ...... Then it matches the #525 reading..
You don't agree about that ?

TP502 + to Q508 E : 1.5 Ohm
TP502 + to Q510 E : 0 ohm (open circuit)
TP502 - to Q508 E : 0 Ohm (open circuit)
TP502 - to Q510 E 1.5 Ohm

post #525
TP502 + TO Q508: 0Ω
TP502 + to Q510E: open circuit
TP502 - TO Q508E: open circuit
TP502 - TO Q510E: 0Ω

 

That is why we take good notes .... to try and prevent such things.

So with those few tests we discovered a number of resistors OPEN and maybe R451 is out of tolerance,

R547: open (Q507)
R569: open (Q515)
R450: open (Q428)
R548: open (Q508)
R570: open (Q516)

R451: 2.4 ohm (Q427) ... can you read the color bands on that resistor .... all I know is it's a quarter watt but I suspect it also is a 2 % resistor or 5% .... which would make it out of tolerance.

Good work ....

The associated transistors (in parenthesis) should be checked before ordering or seeing if you have some good ones in inventory.

Do you have an oscilloscope or access to one? Do you have a signal generator or access to one?

Yes i need to order some resistors there.... which will be the ones in parenthesis?

I will see if i can take a good picture off R541.

I only have my hobbyscope we used a little bit earlier, the DSO138

 

Cool ... but do you have a line level CD player or tape machine or a signal generator?

Hold off on the ordering till we do more checking. That way you will have a good order and hopefully it will be the last order.

Did you also have that ESR tester?

It's been so long I forgot you had that DS138 ....

 

Cool ... but do you have a line level CD player or tape machine or a signal generator?

Hold off on the ordering till we do more checking. That way you will have a good order and hopefully it will be the last order.

Did you also have that ESR tester?

It's been so long I forgot you had that DS138 ....

I don't have a signal generator.. but i have a cd player

And yes, i have a Daniu MK-328 ESR tester...

hehe... i can't blame you.. this thread was down for some time..

 

Ok ....

If you can make a CD ... I can give you a link to some standard level audio files .... left and right channel ....

I'd like you to do some resistance checks .... to see if we have other problems in the X5 Right Channel of the set. It will be point to point, so we are checking a number of components in some tests and a single one in others. You might have to remove some transistors, for this test, so if there are no discrepancies in these tests, you can check the transistors before re-installing them.

Do you have a 2.2 ohm resistor in stock?
Are you ready for more resistance checks?

 

Ok. There are multiple lessons to learn here. I will cover them in separate posts.
Back at post #508, you wrote:

Meter at 200.
Measured:
TP502 + to Q508 E : 1.5 Ohm
TP502 + to Q510 E : 0 ohm
TP502 - to Q508 E : 0 Ohm
TP502 - to Q510 E 1.5 Ohm

So you wrote "0 ohm" while the DMM showed OL.
OL stands for "Over Load" or "Over Limit" or "Open Loop".
Bear in mind that DMM are limited as to how many different characters they can show on seven-segment displays.

(Post #508 has now been edited to show the error.)

 

Lesson #2.

So we have to back track to post #491

Okey!

Measured TP502 + to - : +0.1V
+ to GND: 0V
- to GND: -3.2V

Measured TP401 RIGHT channel + to - : -0.7V
+ to GND: -2.5V
- to GND: -3.3V

You can see the readings at TP401 are consistent, expect for the sign.
(-2.5) - (-3.3) = 0.8V

Where as the readings at TP502 are not consistent. This was a flag that something was wrong.

 

We are going to take some resistance measurements with the POWER OFF.
While you have the board apart, please take two or three photos of the bottom side of the board.
1) Left hand side
2) Right hand side
3) Slightly closer view on the side under TP502, not too close but close enough so that we can clearly see the traces.
Try different lighting and angles to bring out the contrast in the copper traces.

 

Sorry, I referred to the wrong post. I edited my post #556. I will edit post #508 later.
I have deleted your post #559 to avoid confusion.

 

Electronics trouble shooting is detective work.
The path you take is directed by the evidence presented. As they say, "garbage in, garbage out".
When there is misinformation this may nullify all decisions made after that. Hence you have to trace back to where you took a wrong turn and work from there.

Hence let us first confirm how TP502 is connected.