Tried to look up online and I just can't!!! find a service manual for a Denon AVR-2801. The fault is, it does not power up at all, so I did some exploring and found 3 of the power caps, the small cube shaped one's had gone bad, they do have the value on them, but I need to be sure of the exact value....
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Greetings XsamuraiX,
The items shown in your image are bridge rectifiers unless you're referring to the small caps next to them. Nothing fancy. Either way, are you sure you're testing them properly? Based on their proximity to the bridge rectifiers, you are likely seeing continuity through the rectifier diodes. Try reversing your leads if you are measuring in circuit to see if their readings change. You really need to pull the caps and test on an ESR meter to determine if they're bad or not. Also, if those caps are shorted, then I'd make sure to test the bridge rectifiers as they will likely have taken a hit as well.
Go to the hifiengine website for your manual. I was going to send it to you but it's too big. Easier for you to just join the site and get it yourself as they have it available. It's free so no worries about it costing anything.
HiFi Engine - Owners and Service Manuals
Good luck with your project!
Kind regards,
Steve
The items shown in your image are bridge rectifiers unless you're referring to the small caps next to them. Nothing fancy. Either way, are you sure you're testing them properly? Based on their proximity to the bridge rectifiers, you are likely seeing continuity through the rectifier diodes. Try reversing your leads if you are measuring in circuit to see if their readings change. You really need to pull the caps and test on an ESR meter to determine if they're bad or not. Also, if those caps are shorted, then I'd make sure to test the bridge rectifiers as they will likely have taken a hit as well.
Go to the hifiengine website for your manual. I was going to send it to you but it's too big. Easier for you to just join the site and get it yourself as they have it available. It's free so no worries about it costing anything.
HiFi Engine - Owners and Service Manuals
Good luck with your project!
Kind regards,
Steve
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Hi, I tried to find that service manual on that website you said about, but it seems like my model is not there 🙁
You'll just need to log in, it's free.
Denon AVR-2801 Manual - Audio Video Surround Receiver - HiFi Engine
Good luck, let us know what happens. Look for open fuses. Electrolytic problems are common, too.
Yes, going to check other caps, the only 2 caps I have tested are the main, large power caps, they both have 10000uf on the plastic, but my cap meter only reads up to 2000uf 🙁 need to buy a new one, then, to test the smaller, block shaped orange caps there in the picture also, all the fuses are fine, I tested all of them out and all ok.. I'll check those smaller orange caps 1st though as I've been watching video after video after video on Youtube with amps with no power at all, mainly it's always either bad caps, those orange caps or blown transistors. Only problem is, on my Denon, to get access to those transistors I have to remove every circuit board that is attached to the base board 🙁 pain in the butt!
Hi KnD, just abiout to test them, I do hope not, I just tested the large electro caps and they seem to be ok, reading around 9989 each...
Update. Tested out of circuit.
Main cap pair, 10000uf 63v reading as 9945 at best
Film caps, 0.1uf reading as 140
Smaller cap, 1000uf reading as 983
But, for some reason, they will not!!! hold a charge/charge up.
Main cap pair, 10000uf 63v reading as 9945 at best
Film caps, 0.1uf reading as 140
Smaller cap, 1000uf reading as 983
But, for some reason, they will not!!! hold a charge/charge up.
Having some seriously weird test results here (out of circuit caps) reading more than their uf rating, have I got a bad capacitance meter or is the cap just bad, example, 2 x 470uf - 63v caps, one reading as 530 and the other at 441...
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