onkyo tx-sr706 hdmi board

[harleyman58]

ok I have some bad chokes next to the power supply input but I cant find the part does anyone know there I can get these chokes?
rcp1317np470m fixed ind. 47uh 3.3a 69 Mohm ferrite core

[harleyman58]

Re: onkyo tx-sr706 hdmi board

pics of the ind.

[ngvuanh]

Re: onkyo tx-sr706 hdmi board

Try digi-key, search for 47uH, then filter down to 69 mOhm.
There is no thru hole part though, only surface mount.

[harleyman58]

Re: onkyo tx-sr706 hdmi board

cant use surface mount, I have already went through all the normal channels to find the choke. digikey will order some but 100 pieces min, and 6 months order.

[charis]

Re: onkyo tx-sr706 hdmi board

Are you sure that this is the problem.
Long time ago i have service one of them and the problem whas if i remember right the 1.2 volt to the HDMI procesor switch.I change 2 parallel caps . Also another one unit have a dsp chip problem.

[budm]

Re: onkyo tx-sr706 hdmi board

Can we see the location where this inductor is used on the board?
Does it show open circuit? Shows wrong inductance? It will show very low DCR.

[ngvuanh]

Re: onkyo tx-sr706 hdmi board

Can you tell the problem you are having with this unit?
There are 3 power supplies for this board, 1.8V_CORE, 2.4VDSP and 4VHD.
Each section has this coin for filter L8952, L8953 and L8954, so you can jump for testing purpose.

[budm]

Re: onkyo tx-sr706 hdmi board

ONKYO TX-SA706 SR706 SM 1 service manual.

[harleyman58]

Re: onkyo tx-sr706 hdmi board

the number is l8953. it was broken off the board??????

[harleyman58]

Re: onkyo tx-sr706 hdmi board

I have receiver in dvd mode saying no signal, the speakers fl and fr showing output but no sound, or video. also no sound with radio,but no output on speakers lighting up.

[ngvuanh]

Re: onkyo tx-sr706 hdmi board

I have receiver in dvd mode saying no signal, the speakers fl and fr showing output but no sound, or video. also no sound with radio,but no output on speakers lighting up.

L8953 is filter for 2.4V DSP which is power supply for DSP chip.
Try to make a jump to see if you get sound. Make sure you get +2.4V at this rail. BTW, check other power rails also.

[harleyman58]

Re: onkyo tx-sr706 hdmi board

I have 3.9 on the 4.0 rail , 1.8 on the 1.8 rail , 0 on the 2.4 rail with jumper. no sound

[ngvuanh]

Re: onkyo tx-sr706 hdmi board

That's reason why you have no sound since DSP chipset and RAM have no power.
Check pin 11 of Q8953 (Vin) and pin 7 (Vout). Also check L8961, L8963 and L8957.

I have 3.9 on the 4.0 rail , 1.8 on the 1.8 rail , 0 on the 2.4 rail with jumper. no sound

[charis]

Re: onkyo tx-sr706 hdmi board

Are you the first person who is be on this machine?
If not contact the previous service man because the problem seems to be very suspicious.
Now check all voltages with oscilloscope to see if you have ripple on them.
The sympoms are on start that the unit make a digital sound noise because a bad electronic cap on the dsp section.Sometimes you need to add an extra cap below the pcb.If the unit keep playing then the problem goes to hdmi and you get no sound unit goes death.
So know that most of the times the problem is the dsp and the data pins who feeds the rest start probe there.

[harleyman58]

Re: onkyo tx-sr706 hdmi board

I don't have an oscilloscope, I would like to have one but I don't know what to get. I bought the receiver on ebay for 9.99. something cheap to work on.i have several that I bought cheap. I worked on industrial machine electronics, but not audio equipment.all I have is a good meter,fluke that will check diodes and caps.,along with the normal voltages and millivolts. what test equipment do I need besides an oscilloscope? I do need a desoldering station.

[harleyman58]

Re: onkyo tx-sr706 hdmi board

will this work for the choke? digikey #2000-470-v-rc-nd

[ngvuanh]

Re: onkyo tx-sr706 hdmi board

will this work for the choke? digikey #2000-470-v-rc-nd

Yes, this part works. However, you need to work on 2.4V rail first.
You can buy this part but it won't fix your problem since you have 0 on 2.4V rail.

[charis]

Re: onkyo tx-sr706 hdmi board

You said that you have reflow the chip.
May i ask how?
If you dont have proper equipment is better to use an halogen 100w lamp for an hour above the chip not a hot air. And for reference put some solder above the chip to see when he melt.

[harleyman58]

Re: onkyo tx-sr706 hdmi board

I used a lamp but it did not work on the reflow.

[ngvuanh]

Re: onkyo tx-sr706 hdmi board

Do not work on DSP chip until you have +2.4V unless it shorted to ground.