Va old skool

[palerider]

Hello, from va and looks like a great site to learn from, can someone guide me to the post where I can learn troubleshooting old skool pioneer receiver's the SX-1280 thanks.

 

[BlueFox]

Hello, from va and looks like a great site to learn from, can someone guide me to the post where I can learn troubleshooting old skool pioneer receiver's the SX-1280 thanks.

Welcome. Where is 'va'? Is it near 'gina'?

 

[palerider]

Im not far from the west gina line.

 

[amirm]

Welcome. We don't have a dedicated section for repair question. So might as well ask here. What ails that vintage piece of gear?

 

[palerider]

Was working fine went to half volume and stopped now will not power back up? Anyone know if I may be able to bypass on/off switch thanks

 

[amirm]

Very doubtful that the switch is bad. How capable are you with electronics? Are you liable to kill yourself if I tell you what to do next that involves high voltage?

 

[palerider]

No sir I have wired house before, I was thinking I may try fuses I saw in the manual where 4 in bottom and looks like one in the back have to take power cord out I think,
What did you think before I mess with it. I talked to a master out in Cali he wants 1500 to restore but he would not come off any tricks for me and said 9-12 months b4 he can do it
I already have G in the unit and only got to play it one day, she was sounding great till I went half volume then she faded to Black. thanks

 

[amirm]

The fuses would be the first place I would look for sure if there is nothing coming on. If blown, replace them with identical rating as there is 50% chance that they blew due to some short elsewhere in electronics.

Also, disconnect all speaker wires from the unit before powering it back on.

Let us know what you see and then we can go to the next step. Hopefully it is just a fuse!

 

[palerider]

10-4 Going In now

 

[palerider]

Fuses looked good the 250v 12A was coated so I could not see it I did find a 3A 250V so I tried it but nothing I did check unit and it is getting power 120 to first terminal then its like
you need to be geniusX100. I could not find the 5th fuse that is shown on the free hifi engine site where it has additional info plug in selector akr-031 fuse 6a s type Its shows it but
I can seem to find it. I have it unplugged now, I had to set it on side to remove bottom, I have top and bottom off now, it weighs a ton. Im going back in to see if I can find that other fuse.

 

[amirm]

While you have it open but powered off, look closely at all the boards. Use your nose to smell. Does anything look burned, darkened, or smell smokey? Start with the power supply board that is fed by the input power transformer and then find the power amplifier where transistors are mounted on large heatsink. If anything is burned, then the fuse is the least of your problems. If you have trouble identifying these parts, post a picture of the guts and I can guide you.

 

[amirm]

I found a picture:

That is one cramped interior.

Anyway, make sure first, none of the lights for the front panel come on, yes?

The power supply is the circuit to the right of the big round transformer. Look down there and see if anything is charred.

The two amplifiers are vertical modules with black heatsink on left and right. They are hard to see but again, use your nose close to them and see if you smell anything burned.

There are striped red/white wires that go from power supply to the amps. Are they soldered at the ends or go in a socket and can be unplugged?

 

[palerider]

No smell just a bit dusty but not burnt smell at all one side has red and white and other is orange and white all are soldered to pins on board in front of amps, I guess that is the amps with the cooling fins. This is amazing what kind of mind invented this masterpiece. LOL I may have bit of more than I can chew.

 

[amirm]

Unlike new electronics with complicated digital circuits for front panel and such, those units are very easy to work on and repair. That is, for someone who does that kind of work .

Here is an offer. Ship the thing to me at your cost. If it is not dead beyond repair, I will fix it and send it back to you. I can't guarantee that I will be able to fix it but I will give it a try. I have fixed dozens back in the day. If interested, send me a PM and I will give you the contact info. If I do manage to fix it, you don't have to pay me. Just make a donation to a charity for whatever amount of your choosing.

 

[palerider]

PM sent

 

[palerider]

sent another pm thank you