Denon AVR-1706

[diif]

After having success fixing a Sony i decided to take on a friends Denon that was stuck in protect mode.

With the aid of this thread https://www.badcaps.net/forum/showth...ighlight=denon

I was able to locate and identify all of the damaged components.

However on the bottom of the board are two components, i need help identifying them.

D102FL and ZD102FL

They are identical to the corresponding components on the FR channel that have burnt out.

I have located the other parts at CPC so if i could find the suitable components there that would be great.

Service manual on dropbox due to the size limit, i hope this is ok.

[dkneyle]

Re: Denon AVR-1706

Since no one else came back to you I'll put my 2 cents worth in.

I reckon D102FL is a common diode. Try substituting something you have in your parts box, like a 1N4001 or equivalent.

ZD102FL will be a zener diode. Use the good one as a reference. Reverse bias it through a 1 k ohm resistor. Measure the voltage drop across the zener and you'll know its value. The link below is a good little video of how to find the value of an unknown zener.

http://www.youtube.com/watch?v=CtQaGT1qA2M

[diif]

Re: Denon AVR-1706

Thanks dyneyle, i should have updated my post, i contacted Denon direct and they put me in touch with these guys http://www.chsinteractive.co.uk

They gave me these details and had the parts in stock. I just have to work out which way to attach them now.

ZD101FL---- CODE 47003ZJ
ZD102FL --- CODE 47003ZH
D101FL/102FL --CODE 47003ZG

A useful video, thanks.

[budm]

Re: Denon AVR-1706

Are these Diodes located in the power amp or the power supply section? The FL I think it means FRONT LEFT channel.

[diif]

Re: Denon AVR-1706

Hi budm its the power amp section, yes i figured FL and FR indicated the channels, i have the parts and i will trace the FL circuit to see which way round the diode goes in the FR circuit.

[budm]

Re: Denon AVR-1706

I look at the service and cannot see those Diode in the diagram, some of the Zener diodes in the diagrams also use Dxxxx as the designator instead of ZDxxxx.

[diif]

Re: Denon AVR-1706

They were on the other side of the other side of the main board which didn't seem to be in the service diagram.

[diif]

Re: Denon AVR-1706

A quick update, i soldered in the diode and powered up the amp...it powers on and stays on.

However the sound on the left channel is a little quieter and slightly muffled so i need to do a little more investigating.

[tibimakai]

Re: Denon AVR-1706

When you had all the bad components removed, you could have measured the voltage drop on those diodes.

[Caleb]

Re: Denon AVR-1706

If it follows their standard design there should be pots on each channel for setting bias, I would bet that channel needs re-calibrated.

[diif]

Re: Denon AVR-1706

I've come back to this and i had no problem adjusting the pots as per the service instructions. However on the channel i have repaired the voltage is stuck on 0.6mv on the test points regardless of the pot position. I've removed the pot in case it was faulty but this is not the case.

Any ideas ? I've added a second photo with the pins from the pot circled in red.

[Caleb]

Re: Denon AVR-1706

Were the replacement transistors exact replacements? Ive had "compatible" replacements not function correctly as well as chinese parts that were not up to spec. The solder on that pot needs some flux and a reflow too.

[diif]

Re: Denon AVR-1706

Thanks Caleb,
I did get the C1845 from china i have to admit but the transistors and other parts came from cpc so i'm pretty sure they are ok.
I shall locate an alternative 2SC1845
I've been over the soldering since with flux and touched up a few joints.

[stj]

Re: Denon AVR-1706

just swap the suspect part with the one for the other channel.

[diif]

Re: Denon AVR-1706

Good thinking stj, i have swopped the C1845 with another on the board and i still get a static 0.6mv when adjusting the pot. I guess i have missed a faulty component.