CurtPalme.com Home Theater Forum

Robert A. Hill · Joined: 19 May 2006 Posts: 182 Location: Simpsonville, SC

Help! Does anyone have a service manual for the VSX-81TXV? The system works great with analog (multichannel) inputs. Using these bypasses any DSP activity and unit works as basic amp with all 7.1 speakers working.

The MCACC setup does not work and none of the sound processing modes work. I was told the DSP board could need replacing but the replacement part is $180 with labor extra. Maybe something else is wrong (like loose chips or cold solder joints) and I'd love the servce manual to use to troubleshoot. Anyone with experience with this type of problem?

macgyver655 · Joined: 22 Aug 2007 Posts: 8508

Hmmmmmmmmmmmmmmmm..................... Mr. Green

Robert A. Hill · Joined: 19 May 2006 Posts: 182 Location: Simpsonville, SC

Hey Mac! I just had the digital inputs and MCACC working perfectly and they suddenly quit. The analog inputs still work perfectly so it is not in the amp blocks (yeah!). I'm going to open it tomorrow and try to find what is opening when its hot. The guy who owned it said it worked perfectly until he left it on by mistake when he went to bed. When he went into his theater the next day, the sound processing modes did not work. He never got them working again so he replaced the receeiver. This is actually a good sounding unit when it is working. Of course it can always be an analog in amp for my Blu-Ray.

whats6x7 · Joined: 04 Oct 2006 Posts: 5924

Email these guys.

http://www.sybesmas.com/intro.html

I had a problem with the DSP board in a VSX29TX. They sent me an e-mail showing me how to pull the board. I sent the board to them and they fixed it for $50. Works like a champ now.

macgyver655 · Joined: 22 Aug 2007 Posts: 8508

Maybe you'll get lucky and its just a loose harness connection somewhere. I have the service manual and it has fantastic troubleshooting sections. Or try the guys whats6x7 suggested. Let me know if you want the manual.

Oh, check all the screws on the back panel, in and around the inputs and outputs. There are many bulletins from various manufacturers about these loose screws causing all kinds of problems. If they are all good then make sure you check all internal screws including ones that hold the boards in and such. These are very critical in amps and receivers.

Robert A. Hill · Joined: 19 May 2006 Posts: 182 Location: Simpsonville, SC

Thanks to Mac, I found the DSP board quickly. This service manual is very detailed. I did not see any obvious cold joints, but I touched up all the solder on the DSPs and memory chips. I had to do this with the board still in the unit. It would have taken a day just to remove all the screws,cables, and connectors. I can see why this is a $300 service charge to replace it. I sent an emal to Sybasmas to see if they still resolder boards because Pioneer has no placements in stock.

We watched movies all afternoon with no problems using the digital inputs.

macgyver655 · Joined: 22 Aug 2007 Posts: 8508

That is a very detailed service manual. Must be why its 125 bucks. So its working since you had it apart Robert? Did you find any loose harnesses or cables or screws?

Huh. 58 bucks from Pioneer. Thats a switch. Manual is cheaper from the manufacturer.

Robert A. Hill · Joined: 19 May 2006 Posts: 182 Location: Simpsonville, SC

Mac, Its been working flawlessly since I resoldered the chips. I did not see any loose harnesses or screws. The flat ribbon cables were actually very tight in the connectors. I really appreciate you getting the sm. It gave me a lot more confidence to dig in and try to do the repair. Many thanks !

I do not have any HMDI connections as I run my Blu Ray at 720p with component. I also run 7.1 analog out for DVD-A music and I think this sounds much better than the digital out.