Hello. I have a similar issue, no sound (completly silent) through RF path, but all is OK through audio port. My transistor and resistors seem OK. I am suspecting open primary winding in EK522 sound transformer. Unfortunately can't find info about it, like pinout or resistance of windings. Voltages I have on a transistor driving audio transformer are 1,6 V on base and 1V on collector and emitter.
A failed coil is possible but rare. A more likely failure is a marginal solder joint on one leg. Have you checked it for continuity? I don’t have the schematic with me (I’m out of town at this moment) but it’s odd that your collector voltage is less than the base voltage. I’d still suspect a bad transistor before an open coil. Let me know how it turns out.
Hey Mr Brown so my NES is in great condition and sounds was working fine but now ether way I hook it up, sound will play some and then it goes out. Picture is great tho. How could I do a complete repair on the sound?
It's hard to do a diagnosis remotely… but here goes: If the sound goes out it could be a bad connection but more likely it's a bad part. The schematics are really helpful. You can Google & download them and follow the signal path as you read my answer. The audio leaves the large CPU chip at U6 on pins 1 and 2. From there, it's coupled to an inverter by a small 1µF capacitor into an inverter. Next the signal goes to a transistor in the RF modulator (the silver box) and then is coupled by another 1µF capacitor inside the RF modulator straight to the audio out RCA plug. Do you have good audio there? If not, I'd replace both 1µF capacitors, and if that didn't fix it, the transistor (marked C1740; it's a 2SC1740). If the signal is good to that point, there is another 2SC1740 transistor before the RF-Out. Another option for you if you don't have a soldering iron is just to buy a replacement motherboard. I believe iFixit sells them for around $25 USD. I hope this helps… let me know!
@@Mr.BrownsBasement thank you so much friend, I don't know much about it as deep as you do. Now if I just replace the motherboard that will fix everything right? If so where could I get it? If you have a link maybe you could send that to me. Again thank you Mr Brown for all your help. I also see that I can buy the A/V replacement module. Could that fix it also?
Replacing the motherboard is about 90% of what’s inside the machine. If you get a working motherboard you will have a working machine. I just checked iFixit ( www.ifixit.com/products/nintendo-nes-001-motherboard ) and they are currently out of stock. They were selling them for only $25 which was a very good price. It’s not surprising that they’re all gone. The repair you need is not difficult. If you know someone with electronics troubleshooting skills they could fix it for you inexpensively. Even if all the related capacitors had to be replaced along with the two transistors, the total cost in parts would be under $3. I’d caution you against buying a motherboard off eBay unless the seller warranties their boards; while most sellers are reputable I’ve run into a few who are not. Are you in the Greater Toronto Area?
Distortion (fuzzy sound) and oscillation (squealing and motorboating noises) are symptoms of something disrupting the audio signal. It is likely that your NES has an age-related failure similar to the one that affected mine. It’s probably not a complicated fix, but it may be time-consuming. Though my video was only about 15 minutes, the actual repair was closer to a couple of hours.
There is a 10μF coupling capacitor from the logic board video output to the AV section. That cap would cause bad audio and video. See wiki.console5.com/wiki/Nintendo_NES-001#/media/File%3ANES-001-Schematic---Power%2C-AV%2C-RF-Switch.png
Since the signal is capacitively coupled would suggest you do the obvious (and easy): Replace the electrolytic capacitors in the modulator unit, then retest. Unless you have corrosion crawling up the leg of one of the transistors, that should do it. But while you’ve got it apart and open, carefully examine all the transistors. If you see any blue corrosion on any component lead, chances are that component is faulty. You’ll need bright light and a magnifier because it may not be easy to see. Good luck, let me know how you make out.
Hello. I have a similar issue, no sound (completly silent) through RF path, but all is OK through audio port.
My transistor and resistors seem OK. I am suspecting open primary winding in EK522 sound transformer. Unfortunately can't find info about it, like pinout or resistance of windings.
Voltages I have on a transistor driving audio transformer are 1,6 V on base and 1V on collector and emitter.
A failed coil is possible but rare. A more likely failure is a marginal solder joint on one leg. Have you checked it for continuity? I don’t have the schematic with me (I’m out of town at this moment) but it’s odd that your collector voltage is less than the base voltage. I’d still suspect a bad transistor before an open coil. Let me know how it turns out.
Mine had the opposite problem, no audio on AV.
Turns out l9 inductor was damaged. Changed for a 4R9 from a pc motherboard, and worked
Elegant solution!
Hey Mr Brown so my NES is in great condition and sounds was working fine but now ether way I hook it up, sound will play some and then it goes out. Picture is great tho. How could I do a complete repair on the sound?
It's hard to do a diagnosis remotely… but here goes: If the sound goes out it could be a bad connection but more likely it's a bad part. The schematics are really helpful. You can Google & download them and follow the signal path as you read my answer. The audio leaves the large CPU chip at U6 on pins 1 and 2. From there, it's coupled to an inverter by a small 1µF capacitor into an inverter. Next the signal goes to a transistor in the RF modulator (the silver box) and then is coupled by another 1µF capacitor inside the RF modulator straight to the audio out RCA plug. Do you have good audio there? If not, I'd replace both 1µF capacitors, and if that didn't fix it, the transistor (marked C1740; it's a 2SC1740). If the signal is good to that point, there is another 2SC1740 transistor before the RF-Out. Another option for you if you don't have a soldering iron is just to buy a replacement motherboard. I believe iFixit sells them for around $25 USD. I hope this helps… let me know!
@@Mr.BrownsBasement thank you so much friend, I don't know much about it as deep as you do. Now if I just replace the motherboard that will fix everything right? If so where could I get it? If you have a link maybe you could send that to me. Again thank you Mr Brown for all your help. I also see that I can buy the A/V replacement module. Could that fix it also?
Replacing the motherboard is about 90% of what’s inside the machine. If you get a working motherboard you will have a working machine. I just checked iFixit ( www.ifixit.com/products/nintendo-nes-001-motherboard ) and they are currently out of stock. They were selling them for only $25 which was a very good price. It’s not surprising that they’re all gone. The repair you need is not difficult. If you know someone with electronics troubleshooting skills they could fix it for you inexpensively. Even if all the related capacitors had to be replaced along with the two transistors, the total cost in parts would be under $3. I’d caution you against buying a motherboard off eBay unless the seller warranties their boards; while most sellers are reputable I’ve run into a few who are not. Are you in the Greater Toronto Area?
@@Mr.BrownsBasement no sir I'm located in Raleigh NC
@BlackOutlaw_ It was worth asking…
My nintendo NES does work but makes an annoying zooming sound
Distortion (fuzzy sound) and oscillation (squealing and motorboating noises) are symptoms of something disrupting the audio signal. It is likely that your NES has an age-related failure similar to the one that affected mine. It’s probably not a complicated fix, but it may be time-consuming. Though my video was only about 15 minutes, the actual repair was closer to a couple of hours.
Same problem but with the Video and Audio ports
There is a 10μF coupling capacitor from the logic board video output to the AV section. That cap would cause bad audio and video. See wiki.console5.com/wiki/Nintendo_NES-001#/media/File%3ANES-001-Schematic---Power%2C-AV%2C-RF-Switch.png
Im having the same exact problem with mine.. can I send it to you for repair?
If you were local, I would consider picking it up from you and making a video. But that really depends on where you are.
@@Mr.BrownsBasement I don't think so my friend. I live the states
It was worth asking… but if you are having the same problem the repair will likely be similar. The signal path is very straightforward.
I need help AV part no audio
Since the signal is capacitively coupled would suggest you do the obvious (and easy): Replace the electrolytic capacitors in the modulator unit, then retest. Unless you have corrosion crawling up the leg of one of the transistors, that should do it. But while you’ve got it apart and open, carefully examine all the transistors. If you see any blue corrosion on any component lead, chances are that component is faulty. You’ll need bright light and a magnifier because it may not be easy to see. Good luck, let me know how you make out.