Onkyo TX-SR308 Only picture No sound

[syaoran123]

Hi there,
I picked up this onkyo receiver hoping I could fix it. I have done alot of TV repairs before and just started repairing AVRs where this is my third one.

The problem is there's picture but no sound from the main channels or even hdmi out. There is also OSD issues where the text changes and become scrambled as I move the cursor down (see images).

First, I think I should reset/update the OSD firmware before anything else. How is such possible without even a USB port or internet connection? Is it possible to just simply reset the eeprom? Or can I order the chip, replace it, and it will write itself?

FYI: I have already tried factory reset by holding down VCR/DVR and then ON/STANDBY.

[keeney123]

Re: Onkyo TX-SR308 Only picture No sound

I would try first to figure out why you have no sound as this may be causing the other problems with picture scramble. Check the voltages first. Seems like the eeprom may be OK as it is producing a image correctly on the screen.

[syaoran123]

Re: Onkyo TX-SR308 Only picture No sound

Where do I start? Help

[keeney123]

Re: Onkyo TX-SR308 Only picture No sound

Where do I start? Help

First you will need schematics in order to tell where you can make the measurements. Usually you can find these in service manuals. Some service manuals are available on line. You can also start a new thread asking for this service manual for this receiver model number. If you have never repair a receiver or do not have and understanding of electronics this will be very difficult for you to do. You will need a lot of patients. You will need a good DVM and if would be recommended to have a Oscilloscope, depends on how complicated the problem is. You will need to know how to operate these pieces of test equipment. If you do not think you want to go through this then take the receiver to known qualified stereo repair technician.

[madan1]

Re: Onkyo TX-SR308 Only picture No sound

Here is the service manual ( credits to hifiengine ).
I checked it briefly and seems like you burn the firmware as audiocd and then play it through the opticalIN.

About the sound - are any of the sources ( analog and digital ) producing sound? Also for the analog inputs try direct routing ( direct, pure direct, etc. ).

[keeney123]

Re: Onkyo TX-SR308 Only picture No sound

Here is the service manual ( credits to hifiengine ).
I checked it briefly and seems like you burn the firmware as audiocd and then play it through the opticalIN.

About the sound - are any of the sources ( analog and digital ) producing sound? Also for the analog inputs try direct routing ( direct, pure direct, etc. ).

It's very similar to the TX- SR309 that you were working on.

[madan1]

Re: Onkyo TX-SR308 Only picture No sound

This one has better service manual though .
I should try some of the button combinations on my unit... when I have time for it.

[mmartell]

Re: Onkyo TX-SR308 Only picture No sound

The TX-SRx06,07 and I think 08 had dried out 100uf 16v sm electrolytics sometimes damaging the associated voltage regulators. Easy enough to check those caps with an esr meter to rule them out.

Also, some of the x07,x08, x09 and x1x series are under extended warranty due to failed dts chip on the hdmi board. Try heating that ic thoroughly to see if sound returns.

Do you have the speaker icons on the display at all ?

[syaoran123]

Re: Onkyo TX-SR308 Only picture No sound

First you will need schematics in order to tell where you can make the measurements. Usually you can find these in service manuals. Some service manuals are available on line. You can also start a new thread asking for this service manual for this receiver model number. If you have never repair a receiver or do not have and understanding of electronics this will be very difficult for you to do. You will need a lot of patients. You will need a good DVM and if would be recommended to have a Oscilloscope, depends on how complicated the problem is. You will need to know how to operate these pieces of test equipment. If you do not think you want to go through this then take the receiver to known qualified stereo repair technician.

I have a DMM but not an oscilloscope. I have done 3 years of TV repair before and I'm trying to learn AVR repair. I have successfully repaired a Yamaha with capcitor problems and an Onkyo with BGA solder issues. This is my 3rd AVR which I'm trying to repair. I'm doing this as a hobby.

Here is the service manual ( credits to hifiengine ).
I checked it briefly and seems like you burn the firmware as audiocd and then play it through the opticalIN.

About the sound - are any of the sources ( analog and digital ) producing sound? Also for the analog inputs try direct routing ( direct, pure direct, etc. ).

Do you know where I could get the firmware file from? And can I burn the Audio CD and play it on a device like my PS3?

Both analog and digital not producing any sound. Even on direct mode.

The TX-SRx06,07 and I think 08 had dried out 100uf 16v sm electrolytics sometimes damaging the associated voltage regulators. Easy enough to check those caps with an esr meter to rule them out.

Also, some of the x07,x08, x09 and x1x series are under extended warranty due to failed dts chip on the hdmi board. Try heating that ic thoroughly to see if sound returns.

Do you have the speaker icons on the display at all ?

Will change the caps immediately and report to you.

The Onkyo model here doesnt use BGA soldering on the dts chip like others. I have fixed one previously by reflowing, but this isnt the case here.

This model doesnt have room for speaker icons on the display. Only listening modes on the text display and I have cycled thru all of them. See image below.

Any other advice?

[syaoran123]

Re: Onkyo TX-SR308 Only picture No sound

Changing the caps didnt help.

[madan1]

Re: Onkyo TX-SR308 Only picture No sound

Have you checked the low voltage power supplies - +/-7, +3.3 ?
See if there is analog signal reaching the output/switch chip.

[syaoran123]

Re: Onkyo TX-SR308 Only picture No sound

Where can I find these voltage test points?
I can only see 12V on the HDMI board which is normal.

[keeney123]

Re: Onkyo TX-SR308 Only picture No sound

So on the PDF Service Manual you would open. Then go to the edit. In the edit go to search. Select search and put in +3.3. It will search all the +3.3 on the schematics.

[madan1]

Re: Onkyo TX-SR308 Only picture No sound

On the main board ( service manual page 24 )
+/- 15 and 12 V
q5670A
q5671A

+/- 7
j4169
j4161


On the HDMI board - connector p2001 - 5 and 12 V ( page 17 )

check also the troubleshoot diagram on page 4


Oh and be sure to find a good ground point so to not get faulty readings.

[syaoran123]

Re: Onkyo TX-SR308 Only picture No sound

Alright...i got the voltage readings

Im getting good readings for +/- 15V and +/- 7V on the amp board.

Abnormal voltages for 3.3V. Only getting 0.8V for this. The test point im reading from is pin 5 on P201 shown below. Does this mean the HDMI board is faulty? Or perhaps a regulator needs to be changed?

[syaoran123]

Re: Onkyo TX-SR308 Only picture No sound

This came as a surprise.

I traced the 3.3V supply back to its regulator using the schematics.

Next to the regulator Q8951, I found what looks like a burnt out, discoloured SMD resistor R8953 (shown in the attachment). Very hard to see without observing closely but it's there.

Now need to try and find a 27k ohm resistor somewhere.

[madan1]

Re: Onkyo TX-SR308 Only picture No sound

page 22 - there is the 3.3V power supply ( MP2363DN - q8951 ). Looks like all lower V are powered by the +12V on JL801b.
Indeed all of that components are visible on the posted image.

edit - just read your last post, so you found it .

By the way - this HDMI PCB has been repaired previously. C895x caps are originally surface mounted. The JL801B is originally a "push-to-unlock" connector.
I would suggest you to thoroughly inspect the whole pcb.


edit 2 - here is a photo from my ONKYO to see a virgin hdmi pcb ( note the connector/socket and the caps ).


Before repairing anything, be sure that the wires on JL801b are properly soldered. You should also consider installing there some kind of a connector.

[syaoran123]

Re: Onkyo TX-SR308 Only picture No sound

Ya, I already soldered JL801B after I broke it when I tried to disconnect it to solder the caps.

Will report back after I replace the 27k ohm resistor

[syaoran123]

Re: Onkyo TX-SR308 Only picture No sound

I havent managed to replace the 27k ohm resistor yet.

I just tested the connection between 3.3V and GND in diode mode. Got a beep both ways. Measured the resistance, i got low ohm at around 4.6 ohms. I removed the suspicious 27kohm resistor and same thing.

Referred to the schematics in pg 22 of the service manual, and removed every diode and IC that's connected to the 3.3V supply. Only leaving behind the HDMI chip and the DTS chip of course.

Still the same thing. So I started testing the DTS chip for shorts on all sides and every 5 or so pins i heard a beep (and reads 0 ohm).

So looks like Im going to have to buy a new HDMI board

[madan1]

Re: Onkyo TX-SR308 Only picture No sound

switch the multeter to lower scale ( ohms ) and check again.
whats your DTS chip?

If it is the same as mine I can get some readungs for reference.
Also check the pinout of the chip - every other pin could be just ground.

by the way did you remove the 3.3 voltage regulator?