Onkyo TX-6500MKII

Randy007

Active Member
I just came across a nice Onkyo TX-6500MKII quartz locked stereo receiver...speakers would come on sporadically and go out. I pulled the lower plate and behold look at this mess...should i replace with higher voltage filter caps...say 80V? Thanks my friends!1551887378271834342699.jpg 1551887487973-92031873.jpg
 
Voltage is not so important as long as it is equal or greater than original part. You also must pay attention to size - new ones tend to be smaller, but higher voltages are larger, and height and diameter must fit (right diameter is more important looks wise.) . Pay attention to + and - on caps - the red leads go to a positive terminal on one, while the blue leads go to the negative terminal on the other one, and the two remaining terminals go to each other and the black (ground) leads.A very nice receiver - definitely worth resuscitating.
Also, intermittent output is probably not due to filter cap problems, but more likely dirty switches and controls, or flaky relay.
Looks like unit will need a good deoxit cleaning. Good luck with it.
 
Thanks Steve, I'm kinda new at this and I will do a little troubleshooting first. I hope I can find Filter Caps that will fit..I looked at some new 63V filter caps and they are way too small as far as diameter...Height is really not a problem, maybe a larger capacitance rating and voltage...what do you think. the amp runs fine on speaker A, both left and right...but when I hook it up to B, it plays for a few seconds or so and quits...I let it cool down about 5 mins or so and go back to Speaker A and it plays for about 20 mins so far and hasn't shut down yet...defintely overheating, probably the relay?
 
relay just shut off, then came on, shut off again, came on then shut off....defintely a heat problem.....
 
Need help, could the bad 24000uF 63V filter caps cause the protector circuit relay to shut down? Curious asnto why I have a relay that quits working and once it cools it comes back on....sometimes will work for 20 mins or so and sometimes 15 sec. I don't think the relay is bad. Also any ideas where I can find a couple of filter caps they need to be at least 2" in diameter to fit. thanks
 
Please stop using the the big Onlyo lest you jack it up.

Those big main caps look vented and done, junk at this point based on looks alone.

Replace them and rebuild/replace the components on the power supply for starters at a minimum. Post more pictures too of the insides and amplifier boards etc.

You run the risk of more damage using it as is.

Good luck
 
The first step I read in most diagnostics is checking voltages. Check the voltages that the SM shows for the unit and if they are not right there is an issue delivering that voltage to that location. With those tired caps, the rail voltage may be off or the smoothing might not be getting done. I would also guess the current available is no where near design.
 
Please stop using the the big Onlyo lest you jack it up...........

I would get the service manual, and then build and use a dim bulb tester during troubleshooting.
It has saved me before.

I would clean the unit very thoroughly, clean all of the controls, inspect all of the circuit boards carefully, and repair any obvious defects.
That looks like a repair at the bottom of the picture, with all the black wires attached off the left-hand capacitor's negative terminal.

It looks like you have a good project there.
In good working condition that TX-6500-ii should be a very nice receiver.
 
Don't sweat the filter cap diameter issue too much. Just buy ones with the correct capacitance and voltage, and shim them out to proper diameter.
On Mouser's site choosing snap-in type terminals seems to afford the most choice.
 
just got back to this project, having a rough time trying to find the large filter caps...24000uF 63V size 2.5"x 4"....could use either screw or snap in...no one has in stock...even if I go to a higher voltage 100V is next larger voltage cap with this capacitance...still no luck....help please..Thanks!
 
Another option is to gut the existing filter cap cans and stuff the new smaller filter caps in the old cans. Not too difficult at all.

Thanks,
Joe
 
I have done this a couple of times. This is what I would do, but there may be better ways:
Buy through-hole caps (with the wire leads).
Remove the caps from the system.
Remove all that rust to assure that you will have a good surface to solder to, then tin the terminals to assure that you will have clean connection.

Alright so far? Then proceed:
Cut the case near the bottom with a utility knife with a new blade. (Score it first a couple of times to minimize distortion, then cut it carefully.) Remove the innards.
Drill a couple of small holes in the old bottom near the terminals.
Insert the leads of the new cap in the holes in the old bottom and reassemble the case with the new cap inside, assuring that the negative lead on the new cap is aligned with the negative marking on the old cap body. (Aluminum tape seems to work well for holding things together.)
Wrap the new cap leads securely around the terminals and solder in place. Trim the extra lead length. Install the stuffed cans back into their clamps with their terminals oriented to make attaching all those wires easier.

It looks like some negative leads on the left-hand cap are hacked up.
Give some thought to how you can clean up those connections.
 
hows the best way to remove the innards....this stuff is in here tight....

I drove a large wood screw into the center, clamped the head of the screw into a vise, and pulled and twisted the stuffing out. There was some kind of glue holding the stuffing in. One of my caps pulled out rather easily, the other wasn't so easy but the stuffing pulled out reasonably easily after warming the can with a heat gun to soften the glue.

Thanks,
Joe
 
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