Hey @all,
my ipad Pro dont want to work anymore. I measured the incoming amps which is approx. 0.5A. Then I changed the Tristar IC and blow out some parts near this IC. Now I want to find the missing parts. Thats why i´m asking for the schematics & board view for this ipad pro.
820-00301-A
Thank for your help!
Best regards, Mike
Mogli1476
Member
Last Activity: 04-21-2024, 03:21 PM
Joined: 02-04-2015
Location: Hamburg
-
Ipad Pro A1652 12.9" Schematic + Board View needed
-
Hi! These parts are missing. One big cap on the upper left. Two medium caps on the upper middle and two small coils (black) below the middle caps.
The 6 Pin IC right beside the big upper left cap is available and only soldered out to get better access.
please help me with this missing parts. Thanks and best regards,
Mike -
820-00301-ALeave a comment:
-
Thanks!Leave a comment:
-
Ipad Pro A1652 12.9" Schematic + Board View needed
Hey @all,
my ipad Pro dont want to work anymore. I measured the incoming amps which is approx. 0.5A. Then I changed the Tristar IC and blow out some parts near this IC. Now I want to find the missing parts. Thats why i´m asking for the schematics & board view for this ipad pro.
Thank for your help!
Best regards, Mike -
Re: Help with Onkyo TX NR 838
For sure I have an infrared thermometer ;-) The next time i will measure the hottest parts in the receiver and post it here to check if everything is Ok.
I'm not sure yet but i think the Driver Transistors TTA/C 004B on the Pre Amp Board have had approx. 70 degrees after my last measurement but i will post actual values next time.
Regards, Mike...Leave a comment:
-
Re: Help with Onkyo TX NR 838
Otherwise I checked the whole receiver functions yesterday and found nothing corrupt. Everything is working like it should. Only the receiver is getting warm and warmer so that i cannot touch most parts of the PRE Amp Board and also the heatsink for the 15V regulators. Is this normal?
The receiver works and works and works, tested with every hdmi source, flat tv and loudspeakers. Only the heat growth seems not ok for me but the receiver runs for approx. 2 hours and all was ok.Leave a comment:
-
Re: Help with Onkyo TX NR 838
I think this was not the problem. I changed the old Relais from my 609 with this one inside my 838 and measured 330ohms on the old one (838) and 550ohms (609). The Voltage is now changed from 8,7v to 9,2v but everything was working like before.
I'm not sure if this is ok but at the moment it works. The relays in the 609 though is not the same but both have 9V Coil voltage and are switching 120A,250V. I don't know the exact difference between both relays.
Otherwise MPOWERD has now 0,52V instead of 0,37V and that means the...Leave a comment:
-
Re: Onkyo TX-NR414 doesn't switch on
Ok! Thanks ... I think this was not the problem. I changed the old Relais from my 609 with this one inside my 838 and measured 330ohms on the old one (838) and 550ohms (609). The Voltage is now changed from 8,7v to 9,2v but everything was working like before.
Otherwise MPOWERD has now 0,52V and that is the star for low input and that means Q7016 is working.
Thanks!...Leave a comment:
-
Re: Onkyo TX-NR414 doesn't switch on
Hey! I'm not sure to have the same problem like you but i think so. My Nr 838 have had some burned AMPs and now everything is fixed.
But the Voltage at MPOWERD is to low and i thought this is the Relais 9001.
My Relais has approx. 330 Ohms between the coils.
Is that the problem?
Regards, Mike...Leave a comment:
-
Re: Help with Onkyo TX NR 838
So! I'm back again with some more informations. I checked a working TX Nr609 from a friend to be sure which voltage is normal for MPOWER. After Powering on the 609 i measured a voltage of 3,1V on PIN 1 of connector 901. Also like the SM for the TX NR646.
But if i'm measuring the Pin 1 of my 838, there is only 0,5..V during run. This is not normal or what do you think?
I checked Q7016 and changed this too with a working one but it's the same. MPOWER on Q7016 is 3,1V during run and that seems ok i think.
Later i checked...Leave a comment:
-
Re: Help with Onkyo TX NR 838
Another last question before i will check everything is ...
What voltage should i have at PIN 1 on the HDMI Board connector P901? The SM from the 646 says 3V. But I only measure a voltage of 0,3 .. 0,6v. Is there something wrong?
Yesterday i determined that the HDMI Out Signal is like snow on the Main Screen when I switched to USB, NET or Bluetooth.
Also the Network test can't finished without errors but WLan, Ethernet and Bluetooth is working like it should.
Regards, Mike...Last edited by Mogli1476; 04-04-2018, 03:45 AM.Leave a comment:
-
Re: Help with Onkyo TX NR 838
Ok! I will do so ...
I will check all the things step by step tomorrow.
But some information i have before. Yesterday i tried to run the test mode 1.01 but it passes and jumps to test mode 4-19. This mode runs until 4-25 with turning the relays on and off. After this test run the messages RouteTest OK! and VideoDetection Ok! appears. After this NG is displayed.
The time on the display continues but nothing happens and only NG is still in the display.
And VOLH is still between 0,46V...Last edited by Mogli1476; 04-03-2018, 02:39 PM.Leave a comment:
-
Re: Help with Onkyo TX NR 838
Do you mean pressing CBL/SAT + ON/Standby and then Clear appears on the screen? Yes! Thats what i did.
It's possible for me to adjust the pots after warm up to 9-11 mV. I will try this next time. Otherwise i think there is another problem with the main Receiver. Today i removes the Pre AMP Board and turn on the Receiver to start the test modes again.
And whats happened? The same behaviour than with the Pre AMP Board installed. I tried to ran the idling test (Test 1-01) and the same error occurs on the display....Last edited by Mogli1476; 03-29-2018, 04:03 PM.Leave a comment:
-
Re: Help with Onkyo TX NR 838
Yes! I saw these lines in the SM too but that don't help me. In this test mode the receiver switches all channels through (The relays were clicking) and after the last channel, I think SBR+, it shows Video detection OK and after that comes NG.
No WIFi test is starting and the test mode stays in loop. the clock is running but nothing happens.
There is also no Voltage error in the debug window so why should there a voltage protection. The receiver runs good all he time and show no errors.
But what...Leave a comment:
-
Re: Help with Onkyo TX NR 838
Hey guys, good News!
The Receiver is working now. I'm not sure why but after replacing the old final Transistors in the R channel with ones now both are broken again.
Now i installed 2 new TTA/TTC 0002 Transistors from Mouser.
They don't fit perfect but i drilled two new holes in the heatsink and put the to another Position.
I decided to use the bigger TTA/TTC because it's easier to get both from mouser.
After testing the main functions everything seems ok. The Receiver is getting...Leave a comment:
-
Re: Help with Onkyo TX NR 838
Yes! That could be the reason for the fault but i checked all parts on the R Channel and found no error. And if the R Channel have some broken parts on it why there is nothing burned after turning on the receiver?
Is it possible that other parts, for example on the main board, were broken? Which areas do i have to check for a working R Channel?
Thanks, Mogli...Leave a comment:
-
Re: Help with Onkyo TX NR 838
So i have news in this case ...
Found another burned small transistor Q4110 in the ASP Section and a resistor R4120 which was not good. After changing both parts the Receiver stays on and seems to work.
I could adjust the idle current of all channels to the values in the service manual. But after i started the debug mode the display shows NG (Not good). After 15mins of running i adjusted all channels again and it shows no problems.
But after a new debug run the receiver shows NG again before the Wifi check...Leave a comment:
-
Re: Help with Onkyo TX NR 838
Yes! Me too! But a lot of experience is available. I'm not sure that the Pre Amp Board is responsible for the problem but I think so.
Today i disassembled the Pre Amp Board again to check all channels again and again. In hope to find another problem. DO you have an idea how to isolate one of the channels to restrict channel by channel?
Earlier I am using a DC voltmeter to apply a voltage to each channel. I was using 30V DC on Pin4 and Pin5 which is normally 64V but I want to check how the board is recognising.
I...Leave a comment:
-
Re: Help with Onkyo TX NR 838
Today I get new findings in this case.
The Receiver shows the same symptoms then yesterday. After powering on it stays on and approx. 10 - 15sec. later the receiver shuts down.
In the diag Mode the error V (Voltage error) occurs. I think if the VOLH is rising from 043 to 053 so that the receiver wants to change from LOW over MID to HIGH state and therefore voltage is needed from 0,4 - 2,3volts.
But changing from LOW to MID let the receiver go in voltage protection mode.
I'm not sure what exactly the problem...Leave a comment:
No activity results to display
Leave a comment: