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Yamaha RX-V563

 
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irobot



Joined: 13 Mar 2009
Posts: 49

PostPosted: Wed Jul 01, 2009 8:20 pm    Post subject: Yamaha RX-V563 Reply with quote

This one has me baffled -

I Have a Yamaha RX-V563, when plugged in all DC voltages seem to be OK. (Power relay energizes as soon as it's plugged in.)

Main ON/OFF button has no effect. Speaker relays do not kick in. FL display stays off, although voltages seem good on the controller, from about -24 to -29 VDC.

The LIM circuitry is functioning, when applying an external test signal.

This problem is very similar to a Yamaha RX-V361 that I'm servicing.

Both these units use the Sanyo STK433-03 and STK433-130 power amp modules.

Thanks in advance for any help !

Mike.
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jts1957



Joined: 24 Nov 2008
Posts: 2472
Location: Far, Far Away

PostPosted: Wed Jul 01, 2009 9:57 pm    Post subject: Reply with quote

irobot wrote:
Power relay energizes as soon as it's plugged in.


Let's start with that.

Is the relay driver transistor good? Is the signal from the microprocessor to turn the relay driver transistor on/off behaving normally?
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irobot



Joined: 13 Mar 2009
Posts: 49

PostPosted: Wed Jul 01, 2009 11:48 pm    Post subject: Reply with quote

Hi

Thanks for the reply. The power relay driver transistor is good.

The base has about 3 VDC on it as soon as power (AC) is applied, which of course, turns the transistor on and energizes the relay.

I traced the PRY signal. It comes directly off of one of the pins on the DSP (Blackfin) IC.
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jts1957



Joined: 24 Nov 2008
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PostPosted: Thu Jul 02, 2009 1:11 am    Post subject: Reply with quote

Can you find which pin tells IC to output PRY?
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irobot



Joined: 13 Mar 2009
Posts: 49

PostPosted: Fri Jul 03, 2009 7:14 pm    Post subject: Reply with quote

The PRY signal comes off one of the I/O ports, pin 34 on the CPU/DSP. Normally it's at logic high (3.3V) right after power on.
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jts1957



Joined: 24 Nov 2008
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PostPosted: Fri Jul 03, 2009 8:04 pm    Post subject: Reply with quote

Well, does either (input or output) "toggle" along with your command to turn on (or off)?
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irobot



Joined: 13 Mar 2009
Posts: 49

PostPosted: Wed Aug 19, 2009 9:43 am    Post subject: Puzzled Reply with quote

Hi again -

After closer inspection, here's what I found:

All power supply voltages are OK with power relay bypassed.

Standby and System Off buttons do not power up unit.

Of course, no display, although voltages on FD pins and controller seem OK.

/PDET, /RESET, PRV1, PRV2, ACDET, VP, THM, PRD, PRI are all OK, although the LIM signal is missing.

Clock signals are all good throughout the DSP board.

Any ideas?

Thanks,
Mike
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Drdave



Joined: 11 Jun 2009
Posts: 24
Location: South Florida

PostPosted: Wed Aug 19, 2009 1:46 pm    Post subject: Reply with quote

I hate to say it, but it sounds like a bad Micro.
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