The RAM i.c. on these is a known problem: They require resoldering to fix
intermittent / no audio problems. The solder pads at this chip are fragile -
the slightest shearing motion while soldering can damage them.

Mark Z.


"Jiri Kuukasjärvi" wrote in message
...
Hi!

I have this malfunctioning Onkyo TX-DS575 home theater amplifier.
There´s a problem with the DD processor board (quite large PCB,
connected to the display pcb)

As I connect signal to the amp, audio comes out ok. That´s if the
processor board isn´t connected. If it´s connected, audio volume is very
low even if I turn the master volume to the max. If I use the coaxial
inputs.. No sound at all.

The 3.3V regulator (NEC 29M33) seems to be ok.

I already called the local service that has parts for this model.
New board costs 74eur.

So, any ideas on what might be wrong on the board or elsewhere in the
amp? Do you have schematics for machine?

TIA!

- Jiri K.

If it is more than the ram IC's that are defective, it will take some
very sophisticated test equipment, and very in debt knowledge of
servicing your set. Also, you will require the proper soldering tools
to simply change any of the parts. Usually when the fault requires
sophisticated work, it may be more feasible to change the complete
board.

This is not something you can fix at home. If you mess in it, you may
damage other parts, thus increasing the final cost of repairs.

--

Greetings,

Jerry Greenberg GLG Technologies GLG
==============================================
WebPage http://www.zoom-one.com
Electronics http://www.zoom-one.com/electron.htm
Instruments http://www.zoom-one.com/glgtech.htm
==============================================
"Jiri Kuukasjärvi" wrote in message
...
Hi!

I have this malfunctioning Onkyo TX-DS575 home theater amplifier.
There´s a problem with the DD processor board (quite large PCB,
connected to the display pcb)

As I connect signal to the amp, audio comes out ok. That´s if the
processor board isn´t connected. If it´s connected, audio volume is very
low even if I turn the master volume to the max. If I use the coaxial
inputs.. No sound at all.

The 3.3V regulator (NEC 29M33) seems to be ok.

I already called the local service that has parts for this model.
New board costs 74eur.

So, any ideas on what might be wrong on the board or elsewhere in the
amp? Do you have schematics for machine?

TIA!

- Jiri K.

Jerry G. wrote:

If it is more than the ram IC's that are defective, it will take some
very sophisticated test equipment, and very in debt knowledge of
servicing your set. Also, you will require the proper soldering tools
to simply change any of the parts. Usually when the fault requires
sophisticated work, it may be more feasible to change the complete
board.

This is not something you can fix at home. If you mess in it, you may
damage other parts, thus increasing the final cost of repairs.

Yes, I thought so too. Too many special components. I bet if one of them
was broken, and I somehow could have managed to find out, wich one.. No
chance to get a replacement. Replacing SMD components isn´t a problem.
But finding replacements..

I got the service manual & schematics.. But didn´t need them after all.

Seems like it was only the solderings. I reflow the solderings of the
IC´s (Memory & others too) in the DD card with hot air (Danotherm SMD
soldering station) Now it works..

Thanks, Mark & Jerry.

- Jiri K.