9141tc US Ausführung

1. Insert the plug into the power supply (at this time all the indicators are off and there is no sound);
That is correct! The unit is now plugged onto Mains but not yet switched on. None of the two trafos is attached to mains power at this stage yet.

2. Press the power switch of 9141 (2 red LED lights near the power switch are on, one of the LED lights flashes), the others have no response and no sound;
That is correct! The unit is now switched on with its auxiliary power supply unit, but not yet with its main transformer. Thus the unit is in stand by (idle state). It is ready to receive signal from remote control or from any of the unit's signal keys Nos. 9-17 at the unit's front. But the functions are not yet active unless such key is pressed.

3. Press the FM button, all the indicator lights will light up for only 1 second, and all the indicator lights will automatically go out. The sound of the relay switch can be heard in this 1 second, and there is no other response.
That is correct! When pushing the FM button (FM button, No. 9, is one of the signal keys) the unit will switch on fully. The power relay RS653 kicks in and the mains transformer is powered up (that's the relay you are hearing). During this powering up, the LEDs all light up for a moment and then go out, except the LED right above the FM button, which will remain on.

All you wrote so far indicates that your unit powers up exactly as described in the SABA 9141tc owner's manual.

In case, after you pushed the FM button and the unit shuts on but there is no FM reception and even the FM-LED does not light, you might have the MONITOR button pushed. As written in the owner's manual the MONITOR button overrides all other functions and thus deactivates also fm. With other words, if the unit appears not to work, it could be due to the MONITOR button being "on".

Please check that the MONITOR button (no. 19) is not pushed (must be off).

Please show a photograph of the front with all LEDs, after you powered up the unit after you pushed the power-on button und then pushed the TAPE 1 key (No. 17); MONITOR off.
Please show another photograph after you powered up and then pushed the FM button (No. 9), MONITOR off.

If the unit does not react to any keys after it has been powered on with the FM button (and MONITOR is shut off), the unit's power supply board may not supply the required voltages. In that case please measure the voltage at the following test points (indicated on the main board's back side) against chassis ground (after you have switched on the unit with the "power on" button and then with the FM button and you have heard the power relay kicking in):

J1 (shall be 20V DC)
H5 (shall be 15V DC)

Regards,
Reinhard

Thank you friends for your advice,
I followed your instructions and found out if the remote control is faulty. There is no response when you press any key on the remote control. Please advise on how to repair the remote control. Thank you.Thank you friends for your advice,
I followed your instructions and found out if the remote control is faulty. There is no response when you press any key on the remote control. Please advise on how to repair the remote control. Thank you.' data-cke-saved-src='
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Let's stay stay with the receiver for now to confirm in a first place that the receiver works ok without using the remote control.
Does the receiver react correctly if you push the signal buttons on the front of the receiver?
Can you switch between FM, Tape1, Tape2, Phono, etc. with the buttons on the front?
Is there sound if switched to fm (speakers attached of course)?

We focus on the remote control only after you have confirmed that the receiver works correctly (all functions) when operating the buttons on the receiver.
If you can confirm that the receiver works ok if operated from its front buttons, however only the remote control does not work, we can move on - only then.

Sorry, that I am so stubborn. I want to be sure that I understand what works now and what doesn't. You tend to ignore the questions I asked.

Press the button FM-pilot, there is no response, no sound, and the indicator light is off. Press Tape1, Tape2, Phono, am, press these 4 buttons, the indicator light will light up, and it will turn off automatically when it lights up for 1 second.
Press the fm1-7 button, the indicator will light up, and it will automatically turn off in 1 second.

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I asked to push the button FM (button No.9 in the owner's manual) and then tell us, if the FM-LED lights up and you can receive FM.

Instead, you pushed the button FM-Pilot (button No. 18 in the owner's manual), which is for programming the fm pre-set stations. That is useless at this point.
You didn't make the photographs of the front after pushing the buttons fm and tape 1, I had asked for. Please make the photographs (total front, please).
You didn' measure the voltages at the test points J1 and H5 I had asked for. Please measure the voltages.

You wrote: "Press the fm1-7 button, the indicator will light up, and "it" will automatically turn off in 1 second."
Again,....what is "it" and which indicator? The LED light of the fm-station button you pressed turns off or all LEDs shut off?
On the last two photos there is the stereo light on and also the tape 2 indicator light on at the same time. Which buttons did you press and in which order to make these two LED's light up?

I acknowledge that your command of English is poor, may be with a translation program you could understand my questions and answer them. Otherwise we can't help you.



Reinhard

1. Press the FM button (No. 9 button in the instruction manual), the FM-LED lights up, and automatically goes out in 1 second, and there is no sound from fm.

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2. Measure the voltage of test points J1 and H5, there is no voltage, because it is automatically turned off after 1 second after starting, there is no voltage.

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As my English level is extremely poor, the GOOGLE translation software used has errors.

You need to measure the voltages correctly. Your DVM shows "AC" in both cases. That is not correct - you shall measure DC voltage! The display must show "DC".
Please remove the protective foil from the DVM display glass so that one can read more clearly. The foil is reflecting the light so that your photos are blurred.

It looks that on J1 you measure 0,43V AC ripple voltage behind the voltage regulator. In that case IC616 would be defective.

Switch your voltmeter to "Volts DC" and repeat the measurements.

If you still don't measure the correct DC voltages at J1 and H5 (against chassis ground) the power supply board is probably defective. Upon powering up, voltages are present for 1 second and then break down. Possible root cause could be defective parts, i.e. one of those I am indicating in the following (capacitor has an internal shortage or voltage regulator IC is/are defective or resistor is "open"/became highly resistive):

1. Remove the power supply board (power module board) and replace electrolytic capacitors C2218 (3300 µF) and C2217 (1000µF)
2. Check resistor R2217 (22 Ohm/5 W) - does it still have the correct resistance?
3. Replace IC618 (MC78M15) and C621 (10 µF)
4. Replace IC616 (MC78M20) and C617 (10µF)

IC618 and IC616 are both mounted on the heat sinks on the power supply board.

After you have completed these steps, check voltages at H5 and J1 again (against chassis ground). Do you find now the voltages +15V and +20V?

If these voltages are missing or break down the symptoms are those you described: The LEDs turn off and the function buttons don't work anymore. This gives you the false impression that the unit would shut off. But actually that is not true. The unit still remains powered up, but only the functions and LEDs depending on the voltages from J1 and H5 are not working anymore.

your good friend,
1. According to your instructions, I removed the No. 15 board, replaced the electrolytic capacitor, and checked the resistance and voltage regulator tube.
Now the power supply of board 15 is normal.
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2. Insert the No. 15 board into the 9141, press the power switch, and then press the FM button, the indicator light will be on, and it will automatically go out for 1 second, and the fault remains, indicating that it is not a problem with the No. 15 motherboard.
3. I borrowed a 9141 from a friend, and this 9141 is in normal condition. I conducted a comparison check and used the substitution method to replace each of my motherboards one by one on the new 9141. All of my motherboards can start normally, indicating that my motherboards are normal.
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4. Comparative inspection found a problem. The power relay of the original machine is red, but my relay is black, indicating that this relay is not original, but a relay that has been replaced. Please look at the picture I took. Since there is no data on the power relay, I don’t know if there is a problem with this black relay. Ask the data of the relay. What type of relay should be used instead? I don’t know if the analysis is correct.
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The relais you showed is not the original one but has been replaced already (Saba has not used in this model parts "made in China"). Its coil voltage of 24 V DC is correct. The colour plays no role. It is the correct relais on your photo.
Please measure the coil resistance of the relais. If it is in the range of about 800 Ohm to 1,4 kOhm, the relais is likely working ok.

If you want to relace it, you can use this relais:
Finder 40.31.9.024
sources:
reichelt.de/printrelais-1x-um-…n-40-31-9-24v-p28315.html

or ebay article no.: 361147782171

Watch out for:
correct size (about 29 x 11 mm) and correct pin positions
correct coil voltage (24 VDC)
correct coil resistance (within about 800-1400 Ohm)
rated for voltage to be switched across the switching contacts of at least 250V up to 400V and current of at least 5A, preferably 10A

Replace diode D653 (1N4003) located close to the relais. If that diode is leaky, it bypasses current and the relais may open, in case the coil does not get enough current when the unit is switched on.

Regards,
Reinhard

It is still not clear, WHY the LEDs light up and then after one second shut off, after the fm button is pressed.


There are two possible root causes, which should be clarified to figure out, where to search the faulty part:

1. The LEDs shut off and the other functions stop working because the power relay opens and therefore the main transformer is cut from mains voltage

OR

2. the LEDs shut off and the other functions stop working because the power supply does not provide the voltage and current supply (i.e. measuring point H5 and J1) although the power relais is still "on" and thus the main transformer is still powered up. But without the 15V and 20V being present, most of the electronics in the receiver isn't working, including the LEDs.

My questions and recommendations were directed to exclude second option. I asked to check or replace the power supply module (what you did) and the power supply's filter capacitors C2218 (3300 µF) and C2217 (1000µF) for a possible short, what you didn't do. Therefore, option 2. can still not be excluded.

In order to decide on option 2, there is another way:
Shut the receiver on, then press the fm-button so that the LEDs light up and after one second go out. Leave the receiver in this condition connected to mains, don't push any button and measure the DC voltage at measuring point "K1" against chassis ground right after the LEDs went off. If you measure about 13 V at K1, option 2 is correct (main transformer relais is ok and working, fault is in power supply) If you measure 0 V at K1, option 1 is correct (relais or relais switching electronics is defective).

It would be very helpful to narrow the search by deciding between the two options, rather than digging here and there without a reasonable plan and without convincing logic.

Regards,
Reinhard

I checked according to your instructions:
1. The filter capacitors C2218 (3300 µF) and C2217 (1000 µF) are in normal state and there is no problem;
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2. Insert the power cord into the 220v power supply, and then press the power button to make the LED light up and go out after one second. After the LED is off, measure the DC voltage against the chassis ground on the measuring "K1". The result is that the voltage measured at K1 is approximately 15 V.
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3. Then unplug the power cord and measure the K1 DC voltage again, the result is still 15v.
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Can it be concluded that the power transformer is faulty?

I am getting more and more confused.

wyx12007cba schrieb:

Can it be concluded that the power transformer is faulty?

Definitively not! Its shows that the transformer works ok!

Please repeat the measurement of the voltage at K1, but after you pushed the fm-button and the LEDs went off, wait 15 Minutes before you measure the voltage. Keep the power cord plugged in. Within the waiting time of 15 minutes capacitor C2216 slowly discharges through module 31 if supply from the main transformer and rectifier is off. It remains charged if supply from the transformer stll continues. After 15 minutes you should measure ...

....less than 5V at K1 if the power relais has opened
....or still 15V, if the power relay keeps closed.

Therefore, this measurement will tell if the power relais works ok or not.

Please report.

Regards
Reinhard

Your analysis is completely correct, keep the power cord plugged in, and keep measuring K1, 12V without powering on, and keep changing and shrinking the value.
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OK, then the power relais has opened and we shall look for the fault at the power relais and its surrounding.

• Replace the power relay (as you had planned to do)
  
• Replace diode D653 (1N4003)
  

check again afterwards.

regards,
Reinhard

Dear Reinhard and wyx12007cba (this is not your name?),

sorry for rushing late into this topic but I did not read the thread earlier. You are already quite deeply into the repair process but I did get the powering procedure at the very beginning.

“2. Press the power switch of 9141 (2 red LED lights near the power switch are on, one of the LED lights flashes), the others have no response and no sound;”

I have two such receivers in operation and I can’t confirm such behavior.

If I press the power button labelled “stand-by” only ONE LED (above the power button) does light up (permanently).

I know only one flashing LED at this receiver which is the indicator for the remote control labelled “IR sensor”. It flashes if you press one of the source or station buttons at the receiver of any key on your remote control.

Wyx12007cba,
can you please describe, which 2nd LED light up if you press the power button (the mains cable plugged into the power socket)?

Maybe this helps to reduce the amount of possible errors.

Regards,
Wolfgang

Hello Wolfgang.h friend
Your prompt is very accurate,
1/Plug into the 220v power socket, 2/Press the power button, the LED next to the power button will light up, and the other LED will blink constantly, please see the picture:

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Regards,
wyx12007cba

Hello wyx12007cba,

thanks for your feedback and confirmation!

The LED above the IR sensor should not flash after pushing the power button. I tried to study the schematics to find out the reason for the flashing LED.
In my opinion there is something wrong in the IR receiver module (No. 60 in the schematics) probably the integrated circuit IS1706 (SAA1251). Both, the IR-indicator LED and the power relay will be triggered by the IR-receiver module.
Further measurements at the IR receiver module are necessary to locate the error. Reinhard has much more experience than me, I hope he will give some comments on my thoughts.

Regards,
Wolfgang

Wolfgang is right. The power relay is switched on, if there is a positive voltage (>0,6V, most likely several volts, max. 18V) at pin 19 of IC 1706 (SAA1251) of module 60 (IR receiver module) which is connected with the basis of the relay switching transistor T636. If the collector emitter path of T636 switches on, the power relay closes and the unit powers up. This IC is also responsible for the flashing of the IR remote control LED on the unit's front.

The power relay could be defective (mentioned already)
diode D653 could be defective (mentioned already)
or
IC 1706 located on module 60 (IR receiver module) could be defective
or...?

There seems to be a 2nd SABA 9141 available, so that modules can be swapped among both units. That could further narrow the possible causes.
What is the result, after module 60 is swapped?
...It was said above: "I conducted a comparison check and used the substitution method to replace each of my motherboards one by one on the new 9141. All of my motherboards can start normally, indicating that my motherboards are normal." Did this check include swapping module 60, the IR receiver module?





Regards
Reinhard

Hello, two friends,

1/ A chip SAA1251 was found. After replacing it, the LED light continued to flash and the fault remained.

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2/ Remove the No. 60 motherboard on the 9141 which is in good condition, insert it, the LED light continues to flash, and the fault remains.

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I will continue to find the cause of the failure according to the method you provided, thank you.

I plugged two No. 60 motherboards into my other 9141, and it started normally without the LED lights flashing.
I am buying a new power relay and continue testing.

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I am buying a new power relay and continue testing.