Yamaha cr-420 problems
- Thread starter mondoman
- Start date
Install the new relay with the 7 good solder pads. On the final connection wrap a bit of insulated wire around the relay pin and solder the wire to the pin. Solder the other end of the wire to the solder point indicated. When done soldering clean the connections with alcohol or acetone and inspect for unwanted solder bridges to adjacent solder pads.
JB8
Well-Known Member
Repair has been completed, new relay installed as you directed, including the jumper due to missing solder pad - had to get a better light so I could see what I was doing, hence the delay.
Good News - your instructions were spot-on, the fix for the jumper worked as planned, no issues, ugly solder points, but I'm getting there. Initial testing revealed wonderfully quiet output when volume knob at zero, music sounded great via FM, excellent stereo separation, love the sound of this unit thus far. Was not hooked up to speakers, just using headphones, Sony MDR-7506.
Bad News - after listening for 5 minutes or so to let the unit warm up the static came back on the left side, exactly as it sounded before wrangling the relay...
I'm keen on figuring this out and I'd bet my left leg you have a suggestion of what to do next!
Thanks again for your help, determined to sort this.
Good News - your instructions were spot-on, the fix for the jumper worked as planned, no issues, ugly solder points, but I'm getting there. Initial testing revealed wonderfully quiet output when volume knob at zero, music sounded great via FM, excellent stereo separation, love the sound of this unit thus far. Was not hooked up to speakers, just using headphones, Sony MDR-7506.
Bad News - after listening for 5 minutes or so to let the unit warm up the static came back on the left side, exactly as it sounded before wrangling the relay...
I'm keen on figuring this out and I'd bet my left leg you have a suggestion of what to do next!
Thanks again for your help, determined to sort this.
JB8
Well-Known Member
Well, I took the unit in the garage, hooked it up to some speakers (rather than listening through headphones) and let it play for a half hour - no static. If it comes back I'll reach out, and I'll certainly take note of the static vs. audio meets volume scenarios. Hoping it's gone for good but who knows. In the meantime, it's brother arrived from Canada this afternoon, a nice CR-66 II - which has no issues thus far other than slightly dim meter and tuning lights.
For additional context, while avoiding bloviation, I've been flipping units during this quarantine and out of the Pioneers (SX-9000, SX-6000, SX-770), Tandberg (TR-2055), Yamahas (the two noted in this thread), Harman Kardons (330C's) and Sonys I've been cleaning up and sending on, I think the Yamaha's and HK's are my favorite so far. Very nice, warm, easy-on-the-ears sound - and the design of the Yamaha's is fantastic - love the variable Loudness control.
Anyhow, I'm hooked and having fun. Thanks again!
For additional context, while avoiding bloviation, I've been flipping units during this quarantine and out of the Pioneers (SX-9000, SX-6000, SX-770), Tandberg (TR-2055), Yamahas (the two noted in this thread), Harman Kardons (330C's) and Sonys I've been cleaning up and sending on, I think the Yamaha's and HK's are my favorite so far. Very nice, warm, easy-on-the-ears sound - and the design of the Yamaha's is fantastic - love the variable Loudness control.
Anyhow, I'm hooked and having fun. Thanks again!
JB8
Well-Known Member
Cheers, to you as well
In the meantime, I mentioned dim bulbs (meter light x2, tuning pointer x1) on the CR-66 II. Checked the connections everything seems fine. I'd ordered several 12v replacements so I've been experimenting and getting interesting results. Currently, all three are wired correctly based on the schematic, but they're very dim. I pulled the face to clean the film off of the glass, thought that would help some but the lights are still much dimmer than I'd like. Ironically, the CR-20 has a similar issue, but it's lights are completely out. I took one of my new 12v lights and bridged across L1 to L4 and the bulb came on brightly, looked great (CR-420). Then thought, what if I connect another light and maintain the same path, just daisy-chained. Touching to L1 and L4 (bypassing L2 and L3) produced the same results, both lights on, slightly dimmer. I then added the third dais-chained 12v bulb, connecting only to L1 and L4. Low and behold, they all three lit up and just as dim as on the CR-66 II!
Are these bulbs notoriously dim in Yamahas? I'm using incandescent bulbs, btw. Good time for a multimeter test?
I'm just stumped at what L2 and L3 are for and if they're supposed to help keep the lights a bit brighter? Totally a novice on this. When and if you have time maybe you can nutshell what I should be looking for.
In the meantime, I mentioned dim bulbs (meter light x2, tuning pointer x1) on the CR-66 II. Checked the connections everything seems fine. I'd ordered several 12v replacements so I've been experimenting and getting interesting results. Currently, all three are wired correctly based on the schematic, but they're very dim. I pulled the face to clean the film off of the glass, thought that would help some but the lights are still much dimmer than I'd like. Ironically, the CR-20 has a similar issue, but it's lights are completely out. I took one of my new 12v lights and bridged across L1 to L4 and the bulb came on brightly, looked great (CR-420). Then thought, what if I connect another light and maintain the same path, just daisy-chained. Touching to L1 and L4 (bypassing L2 and L3) produced the same results, both lights on, slightly dimmer. I then added the third dais-chained 12v bulb, connecting only to L1 and L4. Low and behold, they all three lit up and just as dim as on the CR-66 II!
Are these bulbs notoriously dim in Yamahas? I'm using incandescent bulbs, btw. Good time for a multimeter test?
I'm just stumped at what L2 and L3 are for and if they're supposed to help keep the lights a bit brighter? Totally a novice on this. When and if you have time maybe you can nutshell what I should be looking for.
The three lamps are wired in series. L2 and L3 are just posts for wire wrapping the lamp pigtails. Power supply is likely 36 volts between L1 and L4 . Each lamp drops 12 volts.
power supply ------>L1---->lamp1----->L2----->Lamp2------>L3----->lamp3-------> L4 ( E (ground))
power supply ------>L1---->lamp1----->L2----->Lamp2------>L3----->lamp3-------> L4 ( E (ground))
JB8
Well-Known Member
I purchased the bulbs through an ebay seller, they're described as (12V-35mA) INCANDESCENT WIRE LAMPS. I also measured the voltage across L1 > L4 and found ~41V on the CR-66 and ~35V on the CR-420. The CR-66 lamps appear to be original, they're just very dim. The CR-420's appear original as well and I believe I've isolated the one bad bulb in the series - if one bulb is out does that break the chain for all three? The meter lights are fine, it's the dial pointer lamp that's out. Assuming I may just need to live with the dim lights on the 66 for now, not a big deal, but I do have the faceplate pulled, so this would be the best time to attack the pointer lamp. I'll replace the pointer lamp on the 420 and see if the series is back on. We shall see.
JB8
Well-Known Member
Replaced all three lights on the 420, they're about as bright as the old ones on the CR-66, so I that's likely as good as it will get unless I switch to LED's, but I have no plans to do that anytime soon.
Still no static on the 420, thankfully. When I pulled the faceplate I saw evidence of excessive moisture at some point, maybe that was the cause of the issue in the relay.
For now I think I'm in good shape, thanks to your instruction and advice. Much appreciated!
Still no static on the 420, thankfully. When I pulled the faceplate I saw evidence of excessive moisture at some point, maybe that was the cause of the issue in the relay.
For now I think I'm in good shape, thanks to your instruction and advice. Much appreciated!
