Hi
Just for fun, I want to service my Yamaha RX-V2500, it is not in use at the moment and I already exchanged the flipflop IC and C4 cap and improved cooling by adding a resistor to the fan powersupply, now it has a 100 hz hum in all speaker outputs, it is always there, not loud but hearable...any thoughts what could cause that, I am planning to exchange the big powersupply caps, could those be the problem?
Thanks for any info and tips,
Tojoko.
Just for fun, I want to service my Yamaha RX-V2500, it is not in use at the moment and I already exchanged the flipflop IC and C4 cap and improved cooling by adding a resistor to the fan powersupply, now it has a 100 hz hum in all speaker outputs, it is always there, not loud but hearable...any thoughts what could cause that, I am planning to exchange the big powersupply caps, could those be the problem?
Thanks for any info and tips,
Tojoko.
Hi,
Found on "tomshardware" if this can help...
If everything looks good with wiring/cabling, have you disconnected ALL devices (TV, BR, CD, to include ALL speakers) and moved/plugged the AVR into another A/C outlet? This will isolate the AVR and help identify that the hum is definitely internal to the AVR and may require repair.
Found on "tomshardware" if this can help...
If everything looks good with wiring/cabling, have you disconnected ALL devices (TV, BR, CD, to include ALL speakers) and moved/plugged the AVR into another A/C outlet? This will isolate the AVR and help identify that the hum is definitely internal to the AVR and may require repair.
Hi
Yes, got another one that works well without hum, so it hums without anything connected, besides speakers, no hum on headphone output..
Cheers, Tojoko.
Yes, got another one that works well without hum, so it hums without anything connected, besides speakers, no hum on headphone output..
Cheers, Tojoko.
Took out the capacitors, they are OK, low ESR and low Vloss, will put them back in, they are 15000µF 71 volts type, I only have 63 volt type lying around, do not want to pay a lot of money on these parts, when they are OK. So, I do not think they are the cause of the hum....
Was the hum present before the fan mod (and other mods)?
Is hum present irrespective of volume control setting? No hum in headphones--- that seems like a clue. Is headphone drive before/after power amp?
Can you post a schematic?
Good luck!
Is hum present irrespective of volume control setting? No hum in headphones--- that seems like a clue. Is headphone drive before/after power amp?
Can you post a schematic?
Good luck!
Hi
Hum is also present with fan completely off, pulled plug, the C4 and flipflop IC did not change the hum, it was already there when I got the amp, it is from 2004, I got it about 5 year ago, did not use it, got another one, did the same mods, no hum....
Just noticed on another pcb a hotspot around a diodebridge, will replace it, when I get a replacement.
What part of the amp you want the schematic for?
Cheers, Tom.
Suspicious looking diode bridge module certainly worth scrutiny.
I was thinking no hum in headphones was an encouraging clue. Are phones driven by PA section or do they precede PA? Associated schematic details might be helpful.
In the event the phones are driven from the PA output, one unlikely thought occurs: with some "switched" phone jacks you can tease plug insertion and get the phones and speakers active simultaneously. If so, is hum then audible in the earphones?
I was thinking no hum in headphones was an encouraging clue. Are phones driven by PA section or do they precede PA? Associated schematic details might be helpful.
In the event the phones are driven from the PA output, one unlikely thought occurs: with some "switched" phone jacks you can tease plug insertion and get the phones and speakers active simultaneously. If so, is hum then audible in the earphones?
Hi
Looks like there is no connection between poweramp and headphone, so it is driven separate from the main amp.
Problem must be in powersupply to the main amps, the servicemanual can be downloaded for free, do not have it here, it is on my pc at work...
Wow, I just resolded a few dodgy looking items, and mounted all the parts, and it is dead quiet now, hurray!
Cheers, Tojoko.
Looks like there is no connection between poweramp and headphone, so it is driven separate from the main amp.
Problem must be in powersupply to the main amps, the servicemanual can be downloaded for free, do not have it here, it is on my pc at work...
Wow, I just resolded a few dodgy looking items, and mounted all the parts, and it is dead quiet now, hurray!
Cheers, Tojoko.