Texas Instrument chip on VSX-921-K AV receiver

[holmzy]

Give us a help guys I'm trying to find out if this chip is faulty or not. It has test points around it but I'm self taught engineer and.....ok I'm just dumb. HELP!!

Its dirty around it because I put flux and heat up but I'm not even sure if the chip works. The bruises on it were there before.

[holmzy]

Re: Texas Instrument chip on VSX-921-K AV receiver

woops didnt attach image before was too big

[tibimakai]

Re: Texas Instrument chip on VSX-921-K AV receiver

Did you look up the data sheet?

[holmzy]

Re: Texas Instrument chip on VSX-921-K AV receiver

I could only find links to aliexpress.com. I nearly said alibaba lol

[holmzy]

Re: Texas Instrument chip on VSX-921-K AV receiver

THERE IS A ALIBABA.com lol

[mmartell]

Re: Texas Instrument chip on VSX-921-K AV receiver

That could be the same series that was going wonky in many Onkyo receivers, can't tell from the pic though.

[holmzy]

Re: Texas Instrument chip on VSX-921-K AV receiver

I am aware of that not sure what series they were. There must be a way to test it. I can see the test points on the circuit board. Has anyone got any ideas at all? willing to try anything pretty much!!

[holmzy]

Re: Texas Instrument chip on VSX-921-K AV receiver

any input?

[tom66]

Re: Texas Instrument chip on VSX-921-K AV receiver

It's a DSP chip. Pretty hard to test. Handles all the fancy audio processing. I believe the service manual for Onkyo and Yamaha amplifiers (if yours is one of those) has ways to "bypass" this chip as part of the fault diagnosis process. Maybe worth taking a look?

[holmzy]

Re: Texas Instrument chip on VSX-921-K AV receiver

Hi Mr.T I thought you only deal with TV's silly me! I tried fixing one of these got bored of TV's but have hit a massive brick wall with amps. I found the service manual but it might as well be in chinese. Also the dts chip is different. I wached a video online and the guy made the amp a pre out from the inside. I'm going to not only try that but also try to feed it a signal also and see if the amp actually works. I have a feeling none of them is going to work. but worth a try I guess. Will post updates.

[holmzy]

Re: Texas Instrument chip on VSX-921-K AV receiver

should mention that it has no sound from analogue or digital or stereo or surround. but boots perfectly normally

[holmzy]

Re: Texas Instrument chip on VSX-921-K AV receiver

I'm such an idiot forgot to mention its a Pioneer

[holmzy]

Re: Texas Instrument chip on VSX-921-K AV receiver

update, looks like the amp section works perfect, well the left channel does. I attached my phone to left channel input to the amp section directly and one speaker. It worked but was low volume. the volume on the amp iself had no effect on sound nor did any source selections or surround modes. normal cd input still did not work.

looks like the issue is from input to the amp section. so from the input board to hdmi board.

any suggestions guys?

[holmzy]

Re: Texas Instrument chip on VSX-921-K AV receiver

anyone?

[CapLeaker]

Re: Texas Instrument chip on VSX-921-K AV receiver

should mention that it has no sound from analogue or digital or stereo or surround. but boots perfectly normally

That's kind of good and not. At least you know that the output stage is O.k. That nothing is working in digital and analog, tells you the problem is before that stage. No error indication is kind of weird, but maybe the problem is in the input stage. Maybe the input selector is bad? Try to see if you can feed it audio and get something back out on the REC side of the tape function.
Also look at page 53 of the service manual (ground points).
Page 16 and 17 show you the block diagram. Try to get the analog working (easier). I guess there is a relay that switches between analog and digital... see what that is doing? No DC on the RCA input jacks I hope?

[holmzy]

Re: Texas Instrument chip on VSX-921-K AV receiver

wow thanks for the input! i will try in couple hours when my daughter sleeps and report back

[holmzy]

Re: Texas Instrument chip on VSX-921-K AV receiver

ok i could only try one thing. the input selector seems to work fine and select any input. all the display and selectors seem to work fine on the outside. i input from phone to tv analog left line in and attached speaker to left line out and did the source selection. then selected pure direct sound and no surround sound. no activity. pages 16 and 17 look very easy to follow (i hope) and will give that a shot first as the grounding thing seems complicated as i have to rip the whole thing apart i think.

[CapLeaker]

Re: Texas Instrument chip on VSX-921-K AV receiver

I had no idea if the unit is together or apart. Some tare it apart, then wonder: why isn't it working? That why I mentioned the grounding thing.

O.k. Seems like the selector is fine. It is always good to have a look at the block diagram first and get a bit familiar with things, before you go and dig into the big schematic.

What happensd to the amp first place?

[holmzy]

Re: Texas Instrument chip on VSX-921-K AV receiver

was given to me. he doesnt know what happened either. just stopped working. been so busy had not had time to look into it.

i did have a look today and still getting nowhere. i did manage to find fl-out from the dsp board and it had no signal. its either the dsp/hdmi board or the 7.1 channel audio board with this chip on it bd3473ks2.

im starting to think that its not the hdmi board mainly because when put amp in direct mode it by-passes the dsp stuff. but i could be wrong.

[ericgonsalves]

Re: Texas Instrument chip on VSX-921-K AV receiver

Hi
I am having a VSX-924-k with the same audio chip and also having the same issue. Checked the amp section and it is working fine but there is no input coming from the audio chip to the amp section. By any chance you managed to sort your problem.