Fixed: Onkyo TX-NR535 clicks, no display

[kubax]

Hi,

i've got a Onkyo TX-NR535 AV-Receiver that does not power on.

It only clicks and nothin happens. Not even the Display is lit up short.

I can force it to power up "completely" if i remove the power connector to the AMP Board (the one directly from the transofmrator) OR if i unplug the HDMI board from the vertical board (leaving any cables connected)

The vProtection and iProtection both are at 0,5v measured through the vias beneath the CPU and using ground from the P9001 connector

The problem stays even with the preAmp Board removed. I suspect the problem be either on the HDMI Board or the Amp Board, but i can not find any obvious problems.

Any ideas what i could test?

Service Manual: https://elektrotanya.com/onkyo_servicemanual_tx-nr535.pdf/download.html

[ambrosia heart]

The vProtection and iProtection both are at 0,5v measured through the vias beneath the CPU and using ground from the P9001 connector.

Of course, once over-current protect is triggered, any shorted CE transisors makes +B voltage flow to speaker terminal,
causing DC protect port voltage larger than 0.  Indeed,
these protect ports ,DC or I, keep zero voltage, always. 

The problem stays even with the preAmp Board removed. The above action proves you have a logical thought  and is,maybe,a good qualified tech.

I suspect the problem be either on the HDMI Board or the Amp Board, but i can not find any obvious problems.

Not related to HDMI board, check ALL  POWER TRANSISTORS mounted on the large heat sink.

How to check?
On board test, using an ohm meter to test ALL CE resistances to see if they are nearly zero.   
Then measure ALL CB and BE resistances and jot
them down.  no more than 2 channels are shorted,
enabling you to make a comparison.

The 3 pins white resistor will open with infinity resistance
instead of 0.22 ohm. Check them ALL.    Any open resistor means transistors is blown. Left 1-2-3 right pins 1-2 0.22ohm, 2-3 0.22 ohm.  In some  special cases,  it won‘t blow but  transistor will due to a very special reason. 

Don‘t tell me no any shorted power transistors.

Do 3 things:
take a photo on top. I tell you how to distinguish I or V protect with posted.
measure ALL CE,CB, & BE resistance jotting them downfor comparison.
Find out shorted one(s).

I am now playing a game no time to read lengthy composition.

[kubax]

Thanks for your help.

Now i'm a litle bit further, but iritated aswell.

I did try to measure in circuit, but the readings were way of close to 0. So i did unsolder every one of them and measured of circuit.

Here are my measurements.

Code: [Select]

1:

CE = OL
CB = 13m Ohm
BE = 13m Ohm
Diode Mode B+E- 0.57v, B+C- 0.57v all other combinations OL
2:

CE = OL
CB = 10m Ohm
BE = 11m Ohm
Diode Mode B-E+ 0.56v, B-C+ 0.56v all other combinations OL
3:

CE = OL
CB = 11m Ohm
BE = 11m Ohm
Diode Mode B+E- 0.56v, B+C- 0.56v all other combinations OL
4:

CE = OL
CB = 11.8m Ohm
BE = 12m Ohm
Diode Mode B-E+ 0.56v, B-C+ 0.56v all other combinations OL
5:

CE = OL
CB = 12.9m Ohm
BE = 12.9m Ohm
Diode Mode B+E- 0.58v, B+C- 0.58v all other combinations OL
6:

CE = OL
CB = 13m Ohm
BE = 13m Ohm
Diode Mode B-E+ 0.58v, B-C+ 0.58v all other combinations OL
7:

CE = OL
CB = 9.8m Ohm
BE = 9.8m Ohm
Diode Mode B+E- 0.54v, B+C- 0.55v all other combinations OL
8:

CE = OL
CB = 11.2m Ohm
BE = 11.5m Ohm
Diode Mode B-E+ 0.54v, B-C+ 0.54v all other combinations OL
9:

CE = OL
CB = 9.5m Ohm
BE = 9.5m Ohm
Diode Mode B+E- 0.54v, B+C- 0.54v all other combinations OL
10:

CE = OL
CB = 12.2m Ohm
BE = 12.5m Ohm
Diode Mode B-E+ 0.56v, B-C+ 0.56v all other combinations OL

After testing with every Transistor removed, i got at least some seconds of display before shutting down.

So i soldered every Transistor back on, and did test in between every single one to see if the problem reoccurs... To my complete surprise, it did not go of instantly as before.

I completely rebuild the AV Receiver to see if it changes when everything is in place, including some of the screws to the back plate to have ground distributed to every board.

Now the receiver stated "Check Speaker Wire" the first two times turning it on, and then returns to the previous behaviour of only clicking... I found that resetting the AV Receiver cycles this process.

Now at least i have a Display, but i don't know where to look next -.-

I think the unsoldering of the Transistors did the same as resetting the device with CBL/SAT + Power. It might have done this in the first place, if i would have known the key combination in advance 

Oh, and resetting the device does not seem to work with the pre amp board removed. Wich did led me to think the problem might be there, but the Transistors and foild caps measure good, i think (foil 4nF)

[ambrosia heart]

See pm 

[kubax]

Ok, so it gets even weirder... Now i can't get it to display "Check speaker wires" anymore. Same problem as in the first post. Resetting is not possible, becuase the relay kicks on and goes of imeadeatly. Unplugging U0030 (pre amp?) changes nothing.

Only if i disconnect the Powercable from the Amp Board it does boot and display works fine (hdmi untested so far)

I tested all the Resistors and Capasitors on the top layer, bottom layer will be tested later, have some work to do now and can't unscrew everything right now

All the 0.22Ohm resistors read 0.50 - 0.54 Ohm (also the big white ones, i forgot to mention this in my last post), but as all are the same, i thing it is because i checked in circuit... but i will desolder one big white one and check whenn is check the ones on the bottom layer of the Board (R6161, R6153, R6143 + Q6073)

Also i forgot to mention that Power Transistor 1 is Q6054 and they are numbered in this order up to Q6060.

I did test all channels, not just the SL one.

I did not mention this up until now, because i didn't think of that. But you could be right with the broken update. I bought the Receiver from a seller localy here, to fix it and replace my RX-V365 because of the missing Audio over HDMI with this old boy. I'm hoping to have 5.1 within Cyberpunk 2077 on Linux, because i can not get this working over Toslink - S/PDIF.

I am able to dump most Nand chips with my TL866+ (T56 is on the way from china, so i can dump even more Nand chips), do you think i should dump it before i try to update with another firmware? Also i have to update with the power cable unplugged from the Amp board, does this affact the update process?


EDIT: Now i did get it to boot properly, but have no clue why. All i did was measuring the components on the preAMP Board, and putting everything together. I had a speaker connected to Center to test with FM / AM if there is any sound, but did not have any (but i also did not have a antenna). After some seconds i did turn it of and noticed a litle electronic smell... The Power Transistors of the SL channel are hot like hell. although there was no heatsink attached, but to my understanding as there is no speaker connected the transistor should not be powered. the other ones were room temperature.

[ambrosia heart]

You are a very good tech. 
I learn a good technique from
you, thank you!!!

No need to do so, see pm
"I am able to dump most Nand chips with my TL866+ (T56 is on the way from china, so i can dump even more Nand chips), do you think i should dump it before i try to update with another firmware? Also i have to update with the power cable unplugged from the Amp board, does this affact the update process?"

Now observe your amp if it can keep turn on 20 minutes.
Remeber : no need to hurry.
See pm.

What I concern most is:
EDIT: Now i did get it to boot properly, but have no clue why. All i did was measuring the components on the preAMP Board, and putting everything together. I had a speaker connected to Center to test with FM / AM if there is any sound, but did not have any (but i also did not have a antenna). After some seconds i did turn it of and noticed a litle electronic smell... The Power Transistors of the SL channel are hot like hell. although there was no heatsink attached, but to my understanding as there is no speaker connected the transistor should not be powered. the other ones were room temperature.

Never do this without heatsink mounted.  If you really want
to test amp section, heatsink is a must OR adjust idling
resistors to minimum service manual P.23. Power transistors get hot once voltage applied.  They get very hot even -/+15v,
let alone -/+56V.


Transistors may thermally broke down/damage leading to
protection due to these steps mentioned above. You need
to check them ,ALL transsistors  and .22Ohm resistors, once again after firmware updated.

Do you have an oscilloscope and a 30-50W 10-30V transformer?  If yes, a fastest way to troubleshoot an amp section with an oscilloscope is good for you

[kubax]

Ok, the problem is almost fixed.

The problem must be (or must have been?) on the SL part of the AMP board. The two Transistors Q6063 and Q6053 were the ones getting hot, untin they suddenly didn't get hot...

I tested with my multimeter and these two transistors suddenly had close to 0 Ohm resistance. So they are blown.

At first soldering them out didn't fix anything.. no sound but running fine. So i did check a litle on the AMP Board, and found that both Fuses were blown. As i did not have 10A Fuses (or 125v) laying around, i did put in two 250V 5A Fuses until the ones i ordered right now arrive (currently all except food stores are closed because of a pandemic lockdown here in germany).

Trying to play a mp3 from a USB stick, i get sound on every channel except SL, but because of the missing Transistors thats fine, i guess 

I also ordered the two transistors (3 x each) so replace them, and see if the problem reoccurs. I doubt that only the Transistors were bad, but i can not find any other problems in the ciruit for now. At least i have some replacements then

First of all i want to thank you for your help, and i will surely report back when the replacements arrive... But now i will reasable it, to change my old receiver and test if i can now play Cyberpunk 2077 in surround from linux 

[kubax]

Just wanted to report back, the Receiver is working now on all channels.

Replacing the two Transistors fixed the problem. Although i have no idea why they measured ok, but seem to be defective.

Thanks for you help

On a site note, i allready did test Cyberpunk 2077 in Linux with now working 5.1 surround and this problem is fixed too. So now i can play it even better