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hemant_2222

Hemant

Last Activity: 04-19-2024, 12:13 AM

Joined: 07-19-2015

Location: Thane

hemant_2222 started a topic Wharfedale Movie Star 70+ Schematic Required.

in Troubleshooting Audio Equipment

04-18-2024, 01:17 AM
Wharfedale Movie Star 70+ Schematic Required.

Hello Friends,

Greetings!

I have taken this active subwoofer from Wharfedale for restoration. This is already in a bad shape as far as the connections goes. It has already been worked by local technicians. The most important part that I am looking forward is the schematic diagram, as there is jumper placed and a track has been cut, as if to bypass the actual connection. I am not sure if this is by design or someone has tried something to achieve.

Another thing is the TDA7294 was badly treated with its legs cut and it had a crack too, so I have replaced it...

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hemant_2222 replied to Marantz SR3001 Full dead

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10-18-2023, 02:01 AM
Re: Marantz SR3001 Full dead

================
The reset IC does gives a -ve pulse for a very short interval. Just like a blip and is maintained at near 5v.

And the reset pin of the micro is held high: near 5v as soon as the power button is switched on. As per the pin diagram it must be held LOW, right..if you could please confirm this.

I am not sure, how to measure the clock though i have an oscilloscope. I don't know the settings to see if the crystal is okay or not.

Any suggestions on the above.
...

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hemant_2222 replied to Marantz SR3001 Full dead

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10-16-2023, 11:30 PM
Re: Marantz SR3001 Full dead

Hello all,

Here are some updates that may help in getting further direction in troubleshooting.

When I keep the multimeter on 200 Ohms with one pin (-ve) grounded and other at pin number ST_BY=0V on CN80, the power relay clicks and there is a display as well, but in a bit skewed manner and when I takeout the +ve pin of multimeter, the relay switches off.

Another, when the same multimeter arrangement is touched on ST_LED=4.42V of CN83, the standby LED is lit up but then no other buttons work on the front panel....

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hemant_2222 replied to Marantz SR3001 Full dead

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10-10-2023, 02:05 AM
Re: Marantz SR3001 Full dead

Hello,

Can anybody put their suggestions, as I am unable to proceed. At least can someone check what are the voltages required by the micro at least to say it is alive.

Thanks,
Hemant

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Last edited by hemant_2222; 10-10-2023, 02:08 AM.
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hemant_2222 started a topic Marantz SR3001 Full dead

in Troubleshooting Audio Equipment

10-08-2023, 10:58 AM
Marantz SR3001 Full dead

Hello everyone,

Hope you are doing well.

This is my first attempt to repair Marantz and the receiver I am looking at is SR3001. It is in fully dead condition.

Here is what has been done/checked so far.

Earlier when I received this unit, I found the primary of the standby transformer was broken. I replaced the transformer with another which now give 5volts at the output of the regulator IC94.

The reset IC96 has the below voltages;
Pin1 --OUT--4.95v
Pin2 --INPUT--7.9v
Pin3 --GND--0v

Voltages...

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hemant_2222 replied to Schematic for Denon Remote Control RC1156

in Troubleshooting Audio Equipment

10-07-2023, 10:51 AM
Re: Schematic for Denon Remote Control RC1156

So Guys, here is the update.

I took out all the possible components, rebuilt the tracks and placed all the components back in place....And it is working now.

But I must say here, with anything we start ...we definitely get to learn something new through every thread..

Keep learning!!

Thank you for your interest in the post..

Regards,
Hemant

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hemant_2222 replied to Schematic for Denon Remote Control RC1156

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10-06-2023, 06:00 PM
Re: Schematic for Denon Remote Control RC1156

Iotas is right, its the crystal/resonator.

I have checked the continuity of those pads to their corresponding connections are they are fine but still I will have that done.

Anybody any more suggestions, like is the voltage divider missing a resistor?

Thanks,
Hemant....

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hemant_2222 started a topic Schematic for Denon Remote Control RC1156

in Troubleshooting Audio Equipment

10-06-2023, 02:05 AM
Schematic for Denon Remote Control RC1156

Hello Everyone,

Hope everyone is enjoying their repairs at hand!.

I am looking forward to get the schematic of Denon remote control RC1156. Actually long time no use of the remote leaked the battery thereby corroding few parts as well as the tracks.

I was able to join few of them but the remote is still not working, so i am looking forward for your help, in case anyone understand the schematic or the remote circuit diagram and could me assist me in repairing it.

Please refer to the attached picture, i think the voltage divider is missing...

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hemant_2222 replied to Yamaha RX-V373 no voltage on the standby switch

in Troubleshooting Audio Equipment

07-02-2023, 07:54 AM
Re: Yamaha RX-V373 no voltage on the standby switch

Hi,

Could anyone advice if we can replace the microcontroller directly or it will require to be progeammed as well.

Thanks,
Hemant

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hemant_2222 replied to Yamaha RX-V373 no voltage on the standby switch

in Troubleshooting Audio Equipment

06-29-2023, 10:10 AM
Re: Yamaha RX-V373 no voltage on the standby switch

The value of R2252 is near 10K....

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hemant_2222 replied to Yamaha RX-V373 no voltage on the standby switch

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06-29-2023, 10:08 AM
Re: Yamaha RX-V373 no voltage on the standby switch

The value of R2296 is approximately 100K (in ckt)....

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Last edited by hemant_2222; 06-29-2023, 10:11 AM.
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hemant_2222 replied to Yamaha RX-V373 no voltage on the standby switch

in Troubleshooting Audio Equipment

06-26-2023, 10:46 AM
Re: Yamaha RX-V373 no voltage on the standby switch

PIN 91 has 1.45v and goes to 0v when the power switch is pressed. I will check the value of R2296 (both in and out of ckt) and will let you know.

Regards,
Hemant...

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hemant_2222 replied to Yamaha RX-V373 no voltage on the standby switch

in Troubleshooting Audio Equipment

06-26-2023, 10:39 AM
Re: Yamaha RX-V373 no voltage on the standby switch

Hi R_J and All,

Here is the full update, I had a chance to work on it further.

With R2229 and R2230 replaced in the ckt, the voltages changed to the previous value. i.e. on KEY1 is 1.7v (PIN 12 of CB221) and KEY2 is 2.7v (PIN 11 of CB221).

Also, it was found that the voltage at either end of R2235 is at 1.32v. ( R2235 was also replaced as it was showing its in-circuit value as 4.2 ohms, which it was when tested out of the circuit.) but the voltage remained the same.

I have now...

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hemant_2222 replied to Yamaha RX-V373 no voltage on the standby switch

in Troubleshooting Audio Equipment

05-30-2023, 09:19 AM
Re: Yamaha RX-V373 no voltage on the standby switch

--------------------------------
Working on the below : from above comments.

When the power button is pressed, one side of R1045 gets shorted to ground and a voltage divider is set up (22K+2.2K+1.5K+1.5K+1K+1K+10K)
The voltage measured between R1043 and R1012 (Key2) is the voltage the micro sees to understand the power button is pressed. Given the voltage and resistances, when the power button is pressed there should be about a 0.8 volt drop across R1012 so the voltage on Key2 should...

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hemant_2222 replied to Yamaha RX-V373 no voltage on the standby switch

in Troubleshooting Audio Equipment

05-30-2023, 09:13 AM
Re: Yamaha RX-V373 no voltage on the standby switch

Hi,

Thank you R_J, I am following you

Here are the updates on the work done till now.

I replaced all the switches to eliminate any doubtful areas but no effect..2.8v remained at it is. Then started removing the resistors one by one from the KEY2 line..R1043, R1041, R1037, and so on but still no success.

Finally removing the R1045 gave the 3.3v on KEY2. (after confirming this, placed the resistors back in the circuit)

With R1045...

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hemant_2222 replied to Yamaha RX-V373 no voltage on the standby switch

in Troubleshooting Audio Equipment

05-28-2023, 01:06 PM
Re: Yamaha RX-V373 no voltage on the standby switch

With R2229 and R2230 removed (and all components placed back on the front panel PCB) I do get a 2.8v and 3.3v on pins 11 and 12 of the cb221 connector.

And on the micro side the volatages are 0.36 and 0.47v...so as said the micro is gone..

What if I get to replace the micro itself.. Any chances... Or it reuquires programming as well..
Or can the current micro be reprogramed..

OR.. Nothing more can be done... And use it for spare parts... Sadly......

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hemant_2222 replied to Yamaha RX-V373 no voltage on the standby switch

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05-28-2023, 04:40 AM
Re: Yamaha RX-V373 no voltage on the standby switch

Another information that I would like to add here is, I had removed R2229 and R2230, again for isolating, but it was lost (being micro in nature) so I had it replaced with 4.2 ohms of small resistance in its place. Would that make much of a difference in the operation. I know it was foolish of me

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hemant_2222 replied to Yamaha RX-V373 no voltage on the standby switch

in Troubleshooting Audio Equipment

05-28-2023, 04:13 AM
Re: Yamaha RX-V373 no voltage on the standby switch

Super explanation. I will try this all soon.

Considering the above detail, I removed R1042 and R1043 for isolation, the voltage on the other side (switches side) of the resistors is now 3.01 and 2.35v respectively. I will check more on this and update soon.

What should be the voltage at the main power switch. It is now at 1.4v in normal condition....

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Last edited by hemant_2222; 05-28-2023, 04:43 AM.
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hemant_2222 replied to Yamaha RX-V373 no voltage on the standby switch

in Troubleshooting Audio Equipment

05-28-2023, 04:08 AM
Re: Yamaha RX-V373 no voltage on the standby switch

I don't think it will do any change....

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