large electrolytics from china

[gogofast]

The original caps have a "U" shaped pin set up on each connection (+/-).
So, each side (+/-) has two pins. The geniuses at Onkyo used each pin for a separate trace (most of them anyway). SO, when you use a normal 2 pin/lead cap, you need to complete the circuits as original.

The closest I could find on mouser were two pin snap in. (for a reasonable price, remember I was fixing TWO amps, 16 caps!) The smallest pin circle was still larger than the original so I had to drill holes further "out". Worried about possible chassis short, I ground out the sub chassis frame around the new holes. The snap in pins were "just" long enough to work.

To reconnect some of the connections, I used 10 or 12 ga. copper wire bent into "U" shape, placed in the open holes and soldered in. Then I soldered the original copper plate back on top of those connectors. Yeah, getting good solder connection there was a trick. I added some braided solder wick over the edges to make sure things made connection. I had a LOT of hot solder flowing around. THEN, I took 12 ga. stranded copper with one the ends stripped to reconnect across the outer pins, lots of solder there too.

It is quite a solder job. I have a big ass Weller soldering "stick" (the Weller gun didn't seem to have the balls for the job).

IF you can find caps with 4 pins that fit. PLEASE share the info.
I predict those amps needing the caps replaced are going to show up a LOT.
I think they ran the caps very close to the rail voltage so they got pushed hard.

thanks for the detailed input!
sounds like a nasty construction job. :thmbsp:

 

[Baron K Rool]

so, no issues after the recap? how does it sound compared to before the recap?

That's a question without an answer, as "audio memory" isn't a thing.

 

[FMB42]

Isn't there a saying "Trying to save pennies will often cost dollars later on" or something like that!

The saying I try to remember is; "Cheapskates always spend the most". And yes, I've found this to be largely true through my own cheapskate ways.

Meanwhile; Chinese quality control coupled with the lack, or difficulty, of a reasonable return policy, would make think twice of buying caps from them (unless no other source was available). Failure and/or fraud rates of 25-50% are a risk not worth taking imo.

 

[toddalin]

It doesn't end at caps. I bought 50 bright white LEDs and at least 20% percent of them fail within their first several minutes of use and a good number more fail thereafter.

The weird thing is that they loose their light output, but they still conduct to the remaining LEDs in the string when wired in series, which don't change intensity after the others fail.

 

[gogofast]

great!
i got all the parts in from the mouser.com. once again, they never fail to impress me on how fast they ship and accuracy of the order.

now, i took a quick look inside the amp, and have to ask:

how do you disconnect these circuit board connectors? i've never seen these before, oh, and i haven't done much solid state gear before - so forgive my ignorance. these connectors have a plastic caps that come off, and i'm not sure if i'm supposed to just pull the wires out or what?

also, do you have to disconnect the heatsinks to get the board out?

those who have worked on the onkyo m504, do you remember?

 

[SoundOfSound]

great!
i got all the parts in from the mouser.com. once again, they never fail to impress me on how fast they ship and accuracy of the order.

now, i took a quick look inside the amp, and have to ask:

how do you disconnect these circuit board connectors? i've never seen these before, oh, and i haven't done much solid state gear before - so forgive my ignorance. these connectors have a plastic caps that come off, and i'm not sure if i'm supposed to just pull the wires out or what?

also, do you have to disconnect the heatsinks to get the board out?

those who have worked on the onkyo m504, do you remember?

Do this before you do anything else.

Gently flip the unit over so you can look at the bottom. Not all, but many units have access panels that you can remove to replace components.

They make life really simple if you have them! :thmbsp:

 

[gogofast]

Do this before you do anything else.

Gently flip the unit over so you can look at the bottom. Not all, but many units have access panels that you can remove to replace components.

They make life really simple if you have them! :thmbsp:

yes, the bottom has a panel that you can open up. so no removing boards? :thmbsp:

 

[SoundOfSound]

yes, the bottom has a panel that you can open up. so no removing boards? :thmbsp:

YIPPIE!!!

 

[whoaru99]

great!
i got all the parts in from the mouser.com. once again, they never fail to impress me on how fast they ship and accuracy of the order.

now, i took a quick look inside the amp, and have to ask:

how do you disconnect these circuit board connectors? i've never seen these before, oh, and i haven't done much solid state gear before - so forgive my ignorance. these connectors have a plastic caps that come off, and i'm not sure if i'm supposed to just pull the wires out or what?

also, do you have to disconnect the heatsinks to get the board out?

those who have worked on the onkyo m504, do you remember?

I see you have your answer about the bottom plate.

But, generically speaking with regard to the connectors, typically they unplug but not always. In some cases the wire ribbons are released to come out of the connector. Someone usually knows for sure from prior experience but I usually just study the connector for a while then you get a feel for how they come apart.

 

[gogofast]

I see you have your answer about the bottom plate.

But, generically speaking with regard to the connectors, typically they unplug but not always. In some cases the wire ribbons are released to come out of the connector. Someone usually knows for sure from prior experience but I usually just study the connector for a while then you get a feel for how they come apart.

never seen these types before. at the end of the cable, the wires are individually going into the connector casing. i'm not sure if they come off at all.

 

[blhagstrom]

never seen these types before. at the end of the cable, the wires are individually going into the connector casing. i'm not sure if they come off at all.

They unplug. There is a "wedge" piece on the white plastic that you have to pull up first. Usually there are small tabs on the ends that allow you to pull "up" away from the connector. Up in relation to the board and connector, "towards" the wire. Then the ribbon pulls out. The ribbon have bare solid wires sticking out. The connector has spring like connections inside. Be gentle. The wedge does not come off, just lifts up.

BUT, BIG BUT HERE. IF you can AVOID taking ribbon cables off, DO SO.
Getting them to make good connection again when you re-insert the wire and push the wedge back in can be difficult! I've had NO END of problems getting good connection again. They too are a royal pain-in-the-ass. Some work fine but others? OMG!

You should be able to do the main filter cap replacement without removing any ribbons. You unsolder from the bottom and you can access through the bottom. I don't remember if there was any glue on the caps. They came out easily once all the un-soldering was done.

 

[gogofast]

They unplug. There is a "wedge" piece on the white plastic that you have to pull up first. Usually there are small tabs on the ends that allow you to pull "up" away from the connector. Up in relation to the board and connector, "towards" the wire. Then the ribbon pulls out. The ribbon have bare solid wires sticking out. The connector has spring like connections inside. Be gentle. The wedge does not come off, just lifts up.

BUT, BIG BUT HERE. IF you can AVOID taking ribbon cables off, DO SO.
Getting them to make good connection again when you re-insert the wire and push the wedge back in can be difficult! I've had NO END of problems getting good connection again. They too are a royal pain-in-the-ass. Some work fine but others? OMG!

You should be able to do the main filter cap replacement without removing any ribbons. You unsolder from the bottom and you can access through the bottom. I don't remember if there was any glue on the caps. They came out easily once all the un-soldering was done.

ah, got it.
thanks again for the input!

 

[wingman0121]

Just wanna tag a question... does the capacitor need to be taken off the board to test the capacitance or as long as it is isolated?

 

[Tom B]

I invested in a very nice Capacitor tester about a year ago. It a Peak-Atlas ESR70+ Measures from 1uf, up past 22Kuf. It can measure value and ESR in circuit, or more precisley out of circuit. This tester allows me to "skip" replacing caps that are fine such as many of the primary filter caps, and allows me to verify the value and ESR of any replacement caps I bought from Ebay. Some caps I have bought on ebay were not the quality I would use for restorations, but I didn't spend much $$ on them anyway. Most caps I bought were fine as I usually stick to Nichicon wherever I can find them on Ebay.