CurtPalme.com Home Theater Forum

[-Pjackso]

Hi guys,
We had a lightning storm and had a very close lighting strike. It struck down at the end of the road and completely toasted the (buried) electric wire for our neighborhood. The electric company is replacing the wire. Point is, we had a VERY close lightning strike.

After the power got turned on again, we checked everything in the house - and no problems. (got lucky)
Everything turned on, even the Yamaha. Worked fine.

About 30 minutes later the daughter and I was dancing to some music (Elvis or Cash, I forget) - and it just turned off.
I pressed the on/off button a few times and no luck. Drat. I unplugged it, and let it sit.
About an hour later, I tried it again - and it turned on and worked fine. Hmmm. Odd.

But now it's dead again - and it won't even try. I don't even hear the relays kicking.
It sounds like power supply issues to me. I opened the case and after 10 minutes of looking around, I have no idea where to start.
Any ideas what to check?



Thanks.

[macgyver655]

Have you tried another outlet just to be sure?

[Tom.W]

Try a light bulb Do you have it on a ground fault outlet by any chance or a power strip ?

[-Pjackso]

I tried it on a completely different outlet.
Nada. Zip. Nuttin.

[macgyver655]

So definitely nothing lit and no noises (clicks or whatever)? Do you have a DMM?

Let me grab the manual, be back.

[-Pjackso]

Yep that's correct. Nothing happens. No lights, no clicks.

I have a DMM.
Thanks.

[macgyver655]

What has me curious is that when it first went down you were able to get it to work again by unplugging. So lets try this first. Make sure all inputs and speaker connection are disconnected.

With the receiver plugged in press and hold these 3 buttons on the receiver for at least 5 to 10 seconds.

Standby/on, A/B/C/D/E and preset tuning right arrow. See if it turns on and what is in the display if it does.

[-Pjackso]

Hi Mac,
Actually here's the long boring story:

...after the first time it turned off:
1) I pressed the on button a few times, and it finally turned back on.
2) shortly after that it turned off again. So I unplugged it and let it sit.
3) I plugged it back in and tried it again and it turned on. Then shortly turned off again.
4) It's now DOA.

I tried your 3-button press and nothing happens.
I checked with the DMM and relay RY301 (near the 120VAC input) isn't turning on.
(I checked across the relay and there's a 120V difference.)

[macgyver655]

Ok, I guess we will have to start at the beginning and see where it goes. Go to the AC input board. Check the 2 fuses, F301 and F302. Then go to the voltage selector board and check fuse, F321.

[-Pjackso]

Fuse 302 is fine.
My unit doesn't have a fuse at F301. mine has a jumper J301. (which is fine)

I looked for a while but couldn't fine F321 (or J321).
Is F321 before or after the transformer?

[macgyver655]

That f321 is on a different board. The voltage selector board. Maybe this unit doesn't have one so don't worry for now if you can't find it.

On that AC input board with fuse F301 there should be a 6 wire harness connected to it. You need to do a voltage test at that connection. I don't know how easy it is to get to but if it's difficult then follow that harness to the main board and see if its easier to test there. Hopefully the board is marked what wire is what because the manual is not giving a pin number.

Anyways your looking for S12 and MG. DMM set to DC voltage, neg leed on MG and pos leed on S12. Plugged in it should read +12v whether it turns on or not. let me know.

[-Pjackso]

MG to S12 reads +13.3V.

[macgyver655]

Very good. Now there are 3 components on that board i need you to test.

R301- DMM on resistance, you should have around 2.2k

D301- DMM on diode scale. You may have to lift 1 end, should show flow in 1 direction, none in the other.

Q301- DMM on diode scale. Test between legs looking for short. Post your lowest readings.

[-Pjackso]

R301 is 2.17K ohms

Q301 lowest reading is 650
1-3 =659
1-2 =1562
2-3 =650


D301 - it reads both ways.
I disconnected the 6-wire harness from the other board, so the other board shouldn't interfere with the reading.
The only thing connected to the circuit is the diode and the relay.
One way reads 504 and the other way reads 960.

Hmmm. I figure the coil in the relay should read the same both ways.
I'll have to lift a leg, but I seem to have misplaced my soldering iron.


That's all the time I've got for tonight.
More after I find that blasted iron.

[macgyver655]

Find that iron yet?

[-Pjackso]

Hi Mac,
Yesterday I had class, but yes - I just found my iron this evening.

I pulled one leg of D301 and it reads in only (1) direction. So it's good.

[macgyver655]

Ok. Lets test the relay now. Hopefully you have a 9 volt battery and 2 pieces of thin wire. Connect a wire from the pos side of the battery to D301 on the side with the stripe. Then connect the other wire to the other side of the diode and just tap the other end on the neg side of the battery. You should be able to hear the relay clicking open and closed.

If you want you can at the same time test the other 2 legs of the relay with your DMM set on diode scale to see if the contacts in the relay are good.

[-Pjackso]

Relay works. 1.8 ohms during contact.

[macgyver655]

Ok, I'm going to need you to attach a wire to that board for future testing. Make sure it is well secured. Attach it to the PRY connection between that S12 and MG you tested previously. I'll look at the prints in a little bit.

[macgyver655]

You need to go to the main board and look for ic528. It should be outputting 5.6v dc.