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?

have a pc, could i use audio output from that instead of using a cd player?

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?

I have a computer here i could use for audio output, would that work?

Yes i have a couple of 2.2 ohm resistors in stock.

I am ready for more tests

Attached a picture of R451

 

Took out the board, and took some pictures of the underside.

I hope they are like you wanted.

At the zoomed in picture, the red arrow points at TP502 +

 

I removed Q508, Q510, Q516 and Q518

I used my MK-328 instrument.
See pictures for readings, not the best contrast on this display but...
Does the readings say they are ok?
I believe so

 

Thanks for the excellent photos.

Confirmed:
TP502 is correctly labeled and matches the circuit schematics.
TP502 + connected to Q508 E
TP502 - connected to Q510 E

Now back to the trouble shooting.

 

Yes, the readings look OK.

ICEO and ICEs are leakage currents and should be zero.

Here is the right channel X5 tests .... make sure the transistors are not installed. No power is applied, in fact unplug it.

copy this to a notepad or a text file .... then you can record the numbers right next to the test. Take your time .... Report the results

This test assumes all the pre-troubleshooting adjustments were done.

Set your meter to the scale just above the resistor value. i.e. 4400 would be the 20k scale.

Right Channel

Q502 E to Q502 C : close to 4400 ohms
Q502 C TO Q504 B: 680 ohms
Q502 E TO Q506 B: 680 ohms

Q504 E TO Q508 B : 2.2 ohms
Q504 E TO Q516 B : 2.2 ohms

Q506 E TO Q510 B : 2.2 ohms
Q506 E TO Q518 B : 2.2 ohms

TP502-2 (assuming the emitter resistor is good, otherwise use TP502-1) to Q512 E - 270.33 ohms + (L502 DC resistance)
TP502-2 (assuming the emitter resistor is good, otherwise use TP502-1) to Q512 B - 0.44 ohms + (L502 and L504 DC resistance)

Q512 B to relay 503 contact ... 180 ohms
Q512 B to relay 502 contact ... 0 ohms
Q512 B to relay 501 contact ... 0 ohms
Q512 B to IC501 pin 1 ... 56k (depending on L504 dc resistance)

Q512 C to D504 anode ... 15k

Relay 501 common contact to R CH B Speaker + : 0 ohms + (L554 dc resistance)
Relay 502 common contact to R CH A Speaker + : 0 ohms + (L553 dc resistance)
Relay 503 common contact to R CH headphones + : 150 ohms

----------------------------------------------------------

Ask if you have any questions.

 

Yes, the readings look OK.

ICEO and ICEs are leakage currents and should be zero.

Here is the right channel X5 tests .... make sure the transistors are not installed. No power is applied, in fact unplug it.

copy this to a notepad or a text file .... then you can record the numbers right next to the test. Take your time .... Report the results

This test assumes all the pre-troubleshooting adjustments were done.

Set your meter to the scale just above the resistor value. i.e. 4400 would be the 20k scale.

Right Channel

Q502 E to Q502 C : close to 4400 ohms
Q502 C TO Q504 B: 680 ohms
Q502 E TO Q506 B: 680 ohms

Q504 E TO Q508 B : 2.2 ohms
Q504 E TO Q516 B : 2.2 ohms

Q506 E TO Q510 B : 2.2 ohms
Q506 E TO Q518 B : 2.2 ohms

TP502-2 (assuming the emitter resistor is good, otherwise use TP502-1) to Q512 E - 270.33 ohms + (L502 DC resistance)
TP502-2 (assuming the emitter resistor is good, otherwise use TP502-1) to Q512 B - 0.44 ohms + (L502 and L504 DC resistance)

Q512 B to relay 503 contact ... 180 ohms
Q512 B to relay 502 contact ... 0 ohms
Q512 B to relay 501 contact ... 0 ohms
Q512 B to IC501 pin 1 ... 56k (depending on L504 dc resistance)

Q512 C to D504 anode ... 15k

Relay 501 common contact to R CH B Speaker + : 0 ohms + (L554 dc resistance)
Relay 502 common contact to R CH A Speaker + : 0 ohms + (L553 dc resistance)
Relay 503 common contact to R CH headphones + : 150 ohms

----------------------------------------------------------

Ask if you have any questions.

Here are my measurements under, in RED color.
Tested probes! -They have a 0.1 Ohm error... just have to say that, i get sometimes 0 ohm, but more often 0.1 ohm.
Don't know what to do to fix it..

Q502 E to Q502 C : close to 4400 ohms - Tested: 3.53 Kohm
Q502 C TO Q504 B: 680 ohms : Tested: 675 ohm
Q502 E TO Q506 B: 680 ohms : Tested: 676 ohm

Q504 E TO Q508 B : 2.2 ohms : Tested: 2.4 ohm
Q504 E TO Q516 B : 2.2 ohms : Tested: 2.3 ohm

Q506 E TO Q510 B : 2.2 ohms : Tested: 2.3 ohm
Q506 E TO Q518 B : 2.2 ohms : Tested: 2.3 ohm

TP502-2 (assuming the emitter resistor is good, otherwise use TP502-1) to Q512 E - 270.33 ohms + (L502 DC resistance)
Tested: (TP502-2) : 264 ohm
TP502-2 (assuming the emitter resistor is good, otherwise use TP502-1) to Q512 B - 0.44 ohms + (L502 and L504 DC resistance)
Tested: (TP502-2) : 0.5 ohm

Q512 B to IC501 pin 1 ... 56k (depending on L504 dc resistance) : Tested: No reading at any range. DMM, OL.

Q512 C to D504 anode ... 15k : Tested: 14.85 Kohm


I have questions about these under here, i see the relays 501,502 and 503 but no markings over or under, i have some numbers on 501 and 502 but don't know how to interpret it, and i will need to measure from the underside, but which pins ?

Q512 B to relay 503 contact ... 180 ohms
Q512 B to relay 502 contact ... 0 ohms
Q512 B to relay 501 contact ... 0 ohms

Relay 501 common contact to R CH B Speaker + : 0 ohms + (L554 dc resistance)
Relay 502 common contact to R CH A Speaker + : 0 ohms + (L553 dc resistance)
Relay 503 common contact to R CH headphones + : 150 ohms

 

Ok ... attached is the datasheet.


Decoding the part number shows it's a two pole relay. On page two of the datasheet shows a diagram.

measure two pins .... one on each side of the relay. Two sets should show and open .... they are the contacts. The third will have some resistance .... about 700 ohms according to the datasheet. on the contact side ... one will go will connect to the speaker output jack (+) and the other will connect to the test point labled.

 

Q502 E to Q502 C : close to 4400 ohms - Tested: 3.53 Kohm

i
Here is the circuit we are addressing. I am assuming Q502 is NOT installed.



Between the E and C we have VR404, which should be in the complete CCW position. That wold be the easiest to check and can vary the reading by 500 ohms. Next component is R504, a 680 ohm resistor. The third component is the parallel combination of R502 and the series connectd R504 and a NTC resistor. There are five components to check. The NTC, Negative Temperature Compensated thermistor can range, on the extremes from zero to 100,000 based on the temperature. I calculated a low end of 1 ohm for that NTC and that made the test at 3.662 k ohms. Let's test the four resistors

VR404: 500 ohms
R504: 680 ohms

Q502 C to Q502 B ... 2.481 k to 3.203 k .....

The lower end could indicate a bad NTC or a resistor out of tolerance. The tests outlined will tell us if you have to desolder some to fully check the other three components.


Q512 B to IC501 pin 1 basically tests R536 (56k). Another way to check that is from TP502 to IC501. If that reading is open, Test TP502 to Q512 B. it's probably close to 0.33 ohms and will tell us the run is good to that point.

The rest are reasonably within a 5% tolerance.

 

i
Here is the circuit we are addressing. I am assuming Q502 is NOT installed.

oops, here is a misunderstanding, i removed the big transistors, but Q502 is still in circuit.

Remove and check again?

 

yes .... please do .... your meter may have started Q502 conducting .........throwing the monkee wrench hard.

 

yes .... please do .... your meter may have started Q502 conducting .........throwing the monkee wrench hard.

hehe.
Measured Q502E to Q502C, without Q502 in circuit: 3.53 Kohm .. so it's the same value.

 

i
Here is the circuit we are addressing. I am assuming Q502 is NOT installed.

View attachment 206175

Between the E and C we have VR404, which should be in the complete CCW position. That wold be the easiest to check and can vary the reading by 500 ohms. Next component is R504, a 680 ohm resistor. The third component is the parallel combination of R502 and the series connectd R504 and a NTC resistor. There are five components to check. The NTC, Negative Temperature Compensated thermistor can range, on the extremes from zero to 100,000 based on the temperature. I calculated a low end of 1 ohm for that NTC and that made the test at 3.662 k ohms. Let's test the four resistors

VR404: 500 ohms
R504: 680 ohms

Q502 C to Q502 B ... 2.481 k to 3.203 k .....

The lower end could indicate a bad NTC or a resistor out of tolerance. The tests outlined will tell us if you have to desolder some to fully check the other three components.


Q512 B to IC501 pin 1 basically tests R536 (56k). Another way to check that is from TP502 to IC501. If that reading is open, Test TP502 to Q512 B. it's probably close to 0.33 ohms and will tell us the run is good to that point.

The rest are reasonably within a 5% tolerance.

Measured:

VR404: 500 ohms TESTED: 482 ohms
R504: 680 ohms TESTED: This resistor is open.. no reading: OL.

Q502 C to Q502 B ... 2.481 k to 3.203 k : TESTED: 34 Kohm


Q512 B to IC501 pin 1 basically tests R536 (56k). Another way to check that is from TP502 to IC501. If that reading is open, Test TP502 to Q512 B. it's probably close to 0.33 ohms and will tell us the run is good to that point.
TESTED: TP502 - IC501 : 34 Kohm
TESTED: TP502 - Q502B : no reading, OL.

 

Ok ... attached is the datasheet.


Decoding the part number shows it's a two pole relay. On page two of the datasheet shows a diagram.

measure two pins .... one on each side of the relay. Two sets should show and open .... they are the contacts. The third will have some resistance .... about 700 ohms according to the datasheet. on the contact side ... one will go will connect to the speaker output jack (+) and the other will connect to the test point labled.

Tested Relay R503

I saw the schematic in your .pdf
It's open at two and has 550 ohm at the third, so guess that's ok then.

I also tested the two bigger relays, they seem to have the circuit between the pins in one end, measured about 1000 ohm both.
And in the other end , the four connectors which goes to the + speaker terminals.
Measurements are open between the four sets of pins in the other end, which they should be as i understand.
Also tested resistance from the four points the relay will connect in to, out to all + speaker terminals, all showes 0 ohm.

EDIT:

Q512B - R503 : 167.7 ohm
Q512B - R502: 0 ohm
Q512B - R501: 0 ohm

R503 - RCH Headphone: ... but this goes through the front panel before jackplug as you know... but you meant the resistance at the board right.... i get 0.5 Ohm .. it goes straight over the board to the connector, not through any component.

 

When you select the speaker ... the relay energizes and the contacts are closed. It will be real evident when you fire it up for the first time if the relay has a problem.

Q502 C to Q502 B ... 2.481 k to 3.203 k : TESTED: 34 Kohm

34 khom would be too high. Are you sure it's not 3.4 kohm

TESTED: TP502 - Q502B : no reading, OL.

Remember ... TP502-1 (+) was open, did you test from TP502-2 (-)?


The colored portion is what you were testing. it shows a connection to Q512 B. I'll assume you removed Q512 from the circuit.

 

When you select the speaker ... the relay energizes and the contacts are closed. It will be real evident when you fire it up for the first time if the relay has a problem.




34 khom would be too high. Are you sure it's not 3.4 kohm




Remember ... TP502-1 (+) was open, did you test from TP502-2 (-)?


The colored portion is what you were testing. it shows a connection to Q512 B. I'll assume you removed Q512 from the circuit.

I will need to check the value Q502C to Q502B again... to be sure.

I see TP502 has a connection to Q512 on your picture, but i didn't get a reading at any of TP502 pins to Q512B.
I have not removed Q512, it is still in circuit.

I will check again soon

 

You know that the TP502 DID go all the way to the speaker relay ..... so half of that circuit you know is connected. I chose those points as they were easily found .... and checked a number of things ....

 

Trying to clean up my errors... i think sometimes, even i write it all down and measures i mix things up...as the amateur i am.
It should not happen.
THANKS for beeing patient with me

Measured again:

Q502B to Q502C: 2.67 K ohm
I believe i measured at the wrong pins earlier

I see in post #572 you wrote this, and i answered under in blue.
Q512 B to IC501 pin 1 basically tests R536 (56k). Another way to check that is from TP502 to IC501. If that reading is open, Test TP502 to Q512 B. it's probably close to 0.33 ohms and will tell us the run is good to that point.
TESTED: TP502 - IC501 : 34 Kohm
TESTED: TP502 - Q502B : no reading, OL.

And i probably measured to Q502, cause i wrote it in my papers, but you wrote i should measure to Q512B.

Here is the correct measurement:

TP5022 - to Q512B: 0.5 ohm

 

Q502 C - B reading is on the lower side of the calculation .... and that worries me because if that thermistor is not working, there is no protection against overheating. If it is working, Can you identify any numbers on that thermistor .....

On the Q512 B to IC501-1 34k ohms is real low as R536 is 56k ohms. That should be examined as well.

IC501 is a protection circuit. It would be nice for it to work properly.

Before this string gets too far along ... it would be nice to make a list of parts needed so when your finished checking, you'll have a list.

I don't see a parallel path that would cause the Q512 B to IC501-1 to drop to 34k.

 

Q502 C - B reading is on the lower side of the calculation .... and that worries me because if that thermistor is not working, there is no protection against overheating. If it is working, Can you identify any numbers on that thermistor .....

On the Q512 B to IC501-1 34k ohms is real low as R536 is 56k ohms. That should be examined as well.

IC501 is a protection circuit. It would be nice for it to work properly.

Before this string gets too far along ... it would be nice to make a list of parts needed so when your finished checking, you'll have a list.

I don't see a parallel path that would cause the Q512 B to IC501-1 to drop to 34k.

The thermistor would be TH502 right? It has only some color code on it.
See attached picture.

Measured right at TH502: 18.47 Kohm
And i measured TH501 on LEFT channel just for comparison: 18.76 Kohm

Measured R536: 34 Kohm ... so it need to be replaced then..

I will make a list shortly, i will check all ceramic resistors so i know how many i will need of them.

 

Now, at 25C the thermistor called for in the service manual would typically be 100 kohms.

That color code could be 100k brown-black-yellow.

I think we should check the x5 left channel before ordering. are you feeling up to it?

If so .....


Left Channel

Q501 E to Q501 C :

Q503 E TO Q507 B : 2.2 ohms
Q503 E TO Q515 B : 2.2 ohms
Q503 C TO Q505 B: 680 ohms
Q503 E TO Q507 B: 680 ohms

Q503 E TO Q507 B : 2.2 ohms
Q503 E TO Q515 B : 2.2 ohms

Q505 E TO Q509 B : 2.2 ohms
Q505 E TO Q517 B : 2.2 ohms

TP501-2 (assuming the emitter resistor is good, otherwise use TP502-1) to Q512 E - 270.33 ohms + (L501 DC resistance)
TP501-2 (assuming the emitter resistor is good, otherwise use TP502-1) to Q512 B - 0.44 ohms + (L501 and L503 DC resistance)

Q511 B to relay 503 contact ... 180 ohms
Q511 B to relay 502 contact ... 0 ohms
Q511 B to relay 501 contact ... 0 ohms
Q511 B to IC501 pin 1 ... 47k ( + L504 dc resistance)

Q511 C to D504 anode ... 15k

Relay 501 common contact to L CH B Speaker + : 0 ohms + (L552 dc resistance)
Relay 502 common contact to L CH A Speaker + : 0 ohms + (L551 dc resistance)
Relay 503 common contact to L CH headphones + : 150 ohms


Let me know when your done.

Once that is done, with no transistors in the x5 section, we will fire it up .... make sure everything is working up to the X5 subsection.

I'll have that test procedure for you before we do it.