Hi i got recently AVR 141, it have two issues one is it going protection mode some times and its surround right channel have volume issue when i am increasing the volume it goes on increasing but suddenly lowering when i reach -42db then it have no change till -28db when reaching --27db it again increasing to a level which is same level of other channel ... i dont know what is causing for this volume issue even i did reset no changes, regarding the random protection mode , i checked the voltage out put at speaker terminal in front right channel its showing around 2.1 volt but other channel shows in milli voltae range so i suspect problem with front right channel. hope it can be fix, but i dnt have any idea about volume issue on surround right channel any one can help me
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Re: Harman Kardan AVR 141 protect mode and volume issue
any one can help me -
Re: Harman Kardan AVR 141 protect mode and volume issue
Pictures on the insides will go a long way towards getting help
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Re: Harman Kardan AVR 141 protect mode and volume issue
hi,,, i want fix the volume issue first , is it problem wit IC njw1197 (dogital volume control ic) only have problem with Right surround, this IC have two unused pins for Surround back channels , but how i can enable this pins to divert audio signal from SB right to this - schematic i attached hereLast edited by srt1; 12-07-2017, 03:24 AM.Comment
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Re: Harman Kardan AVR 141 protect mode and volume issue
Maybe, that channel has a bad component.Comment
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Re: Harman Kardan AVR 141 protect mode and volume issue
I deverted the signal to other channel but ,its same ..so i am.thinking problem with mcu or this digital volume ic .but i need to confirm itComment
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Re: Harman Kardan AVR 141 protect mode and volume issue
Typical "Protect" problem on this model is bad transistors KTC3200 - the differential pair on the Power Amplifier circuit. You must to replace to 2SC1845 of all pair as Q514/519 ,Q818/819 etc.Comment
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Re: Harman Kardan AVR 141 protect mode and volume issue
Don't fix volume problem first, fix amplifier.
Capacitors C501,2,3,4,5 etc. shorted can blow up the DAC.Comment
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Re: Harman Kardan AVR 141 protect mode and volume issue
I measured voltages at points collector terminal of q876 & q886 its +3.2volt and 0.66volt respectively , but in other channel its +1.3volt and -1volt.. This protection mode only happening when i switch on in cold coundition after few times restart it will stay power on.. when i amm switch on cold condition its showing around 3 volt on speaker terminal , but after few minutes its lowering ,becaming 2 volt .. then receiver stay aliveComment
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Re: Harman Kardan AVR 141 protect mode and volume issue
Try to freeze the differential pair and you will see a change of the DC offset
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Re: Harman Kardan AVR 141 protect mode and volume issue
i need help regarding the volume issue also.. if it faulty NJW1197 ic , i want divert the audio signal to other channel which is unused as this ic has 8 channel volume control is ther now only its 6 channel used ,,hope i can use one channel out of 2 in remaining , but i dont know how to configure it..Comment
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Re: Harman Kardan AVR 141 protect mode and volume issue
HI, I replaced C3200 with C1845, now amplifier section is ok.. but i want fix the volume issue on Surround right channel.Comment
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Re: Harman Kardon AVR 141 protect mode and volume issue
hi,
i wil try too explain my problem in my best English (i'am from Belgium)
when i switch on my HK VR 141, after few seconds, "protect" appair on the screen and the HK shut down.
someone can tell me the origin of the problem?
best regardsComment
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Anyone run memory speed tests with an old X58-based triple channel 1st gen or any other >2 channel board? The one I have is a Gigabyte I think.
Anyway I had four 4GB DDR3-1333 modules in the 6 memory slots and got around 11GB/sec memory speeds assuming that it went dual channel since it didn't have enough modules for triple channel. Now I stuck in two more 4GB modules, but they are DDR3-1600. I'm still getting 11GB/sec speeds according to memtest86...
Just wondering, anyone do memory speed analysis on these triple (and higher) channel memory boards? Are there any... -
Hi friends
I have reverse engineered this tester, schematic is attached and is complete except for capacitor values. These testers annoyingly have no model number but they are the ones you find on the first page of just about any website if you type in "18650 4-channel tester". There is also a 2-channel variant and a newer 8-channel variant. They are very cheap (about £15) and can measure voltage, current, internal resistance and capacity. They have a multicolour display for all these statistics. They also have terminal blocks so that if you want to use a breakout board... -
Hi,
I bought a used Marantz SR5007 and it's giving me some issues that I can't seem to really place. It functions well in most settings, ARC mostly works, it has no issues driving my speakers in any of the digital input modes, but I'm having issues running analog inputs in direct or pure direct mode. For some reason in this mode there's distortion for every volume increment I give it, but once the volume is stable it has no issues. Muting creates a loud pop, switching to another source also causes a pop and so does turning off the amp in that mode. Again, no issue in the digital modes.... -
Hi everyone,
I'm working on a MacBook Air 2020 (A2337, board 820-02016) and running into a strange USB-C issue. I've gone through quite a bit of testing and part replacement, but I'm stuck — hoping someone here can shed some light.
🛠 Original Issue
The machine initially wouldn't negotiate 20V over USB-C — stuck at 5V.
Diagnosis showed PP1V5_UPC0_LDO_CORE shorted to ground.
I replaced U3100 (UF400) using a donor board (A2179), and the machine powers on fine now.
⚠️ New Problem: One USB-C Port Only Works in One Orientation... -
Hello,
I know some might say... just buy another one. Sell it as parts..!
So had this AMP for quite some time. Recently I saw light smoke coming out of the AMP. Had my fire extinguisher close by. Just kidding. Turned immediately all devices off from mains.
Let things cool a bit, and opened up the amp device. I clearly saw on the main board which hosts the 5X amp (5.1), 3 10 ohms 1W resistors had their leads looking black, while the rest of the remaining 2 x 10 ohms were brownish as being installed from factory.
Spent some time downloading the Service...06-11-2024, 08:38 AM
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