Project: Yamaha CR-820 (Rebuild)
Olliedazzle
New Member
Yamaha5000
Never settle for 2nd best
WOW!!! Yamaha sure made major improvements in the service manual from prior.
70smidfiguy
Active Member
"Went back in and changed the LED resistor setup.... timing is right now (no sneaker on the gym floor sound on turn off)."
I have the same issue after upgrading to LED's.
I put a 470ohm current limiting resistor at on one side of the 5 x LED circuit.
Can you advise on what config worked for you with resistors to set the relay timing correctly?
Many thanks in advance.
I have the same issue after upgrading to LED's.
I put a 470ohm current limiting resistor at on one side of the 5 x LED circuit.
Can you advise on what config worked for you with resistors to set the relay timing correctly?
Many thanks in advance.
Super Noob
Super Member
Had to look at my notes on the CR-620...
On to the LEDs... went with similar setup as the CR-820 with much luck:
Wired a 1W 470 ohm resistor on each series paired ahead of the light diodes... purist will say they suck, but I like them and that is what counts.
70smidfiguy
Active Member
Thanks and your guide above is spectacular!
I actually decided to replace with the incandscent bulbs and ensure the relay delay was never an issue!
I removed the "blue" tinted lenses and used the natural incandescent lighting.
As you say, it's what you think that really counts!
I actually decided to replace with the incandscent bulbs and ensure the relay delay was never an issue!
I removed the "blue" tinted lenses and used the natural incandescent lighting.
As you say, it's what you think that really counts!
cuda440
Well-Known Member
Thanks for the BOM. I've been using it on a friends 820. My first Yamaha.
Heads up to anyone working on one of these or something similar. There is a two piece "T" shaped frame on the underside that supports the two main boards. To gain access to some of the parts for removal it needs to be removed. Easy enough, just take the screws out.
Take note: this piece is used to tie the grounds together. If you turn the unit on without this part in place, the ground floats all over and the protection relay will not click on. It took me a couple of days of head scratching to finally figure this out.
Heads up to anyone working on one of these or something similar. There is a two piece "T" shaped frame on the underside that supports the two main boards. To gain access to some of the parts for removal it needs to be removed. Easy enough, just take the screws out.
Take note: this piece is used to tie the grounds together. If you turn the unit on without this part in place, the ground floats all over and the protection relay will not click on. It took me a couple of days of head scratching to finally figure this out.
Snow_
New Member
Is the plastic on the power transistors that are mounted on the heatsink needed? Because theoretically the screw connects the casing (which also should be the emitter) to the heatsink, or will I short something if I leave the Plastic(?) out.Filter cap bracket needed to be moved down to accommodate the shorter caps...
There are some caps and components between the transformer and side wall - you will have to loosen the transformer and slide out of the way.
Pulled, cleaned, and re-greased the outputs.
As you can see... I went ahead and did all the diodes, VRs, and transistors (minus the outputs).
Also very much appreciate you recording your work, well done and thank you!
Kind regards
Konrad aka Snow
cuda440
Well-Known Member
Those are mica insulators and yes, you absolutely need them to prevent shorting the case to the heat sink! If undamaged you can reuse them, but everything should be cleaned of the old thermal grease before a thin, fresh application of thermal grease applied to both sides of the insulators.
cuda440
Well-Known Member
The power transistor socket fits into the heatsink holes to perfectly register the screws and the two transistor leads such that no electrical connection is made to the heatsink itself. Care must be taken that the sockets are properly seated in the heatsink when reassembling.
Snow_
New Member
Thank you very much, I have bought new ones that I will install before any powering up. You saved me from potential damage, cheers!
Snow_
New Member
May I ask what your reasoning was for replacing the diodes? Were they not functioning?Up first was the main board - power supply and amp.
Main Control Board / Amplifier (NA06909-1)
C633-C634 – Original 10uf 25v (signal) / Now UKL1V100KDDANA
C637-C638– Original 2.2uF 50v (signal) / Now WIMA MKS2C042201K00KO
C709-C710 – Original 47uF 6.3v (signal) / Now 47uf 25v UKL1E470KEDANA
C713-C714 – Original 220uF 6.3v / Now 220uF 16v UKA1C221MED
C723-C724 – Original 100uf 35v / Now 100uF 35v UKA1V101MED
C727-C728 – Original 4.7uF 6.3v / Now 4.7uF 63v WIMA MKS2C044701M00KO
C743-C744 – Original 1uf 50v / Now 1uF 63v WIMA MKS2C041001F00JA
C745-C746 – Original 1uf 50v / Now 1uF 63v WIMA MKS2C041001F00JA
C751-C752 – Original 1uf 50v (BP) / Now 1uF 63v WIMA MKS2C044701M00KO
C801- C802 – Original 22uf 25v / Now 22uF 35v UKL1V220MEDANA
C803 – Original 4.7uf 35v / Now 4.7uF 63v WIMA MKS2C044701M00KO
C804 – Original 33uf 16v / Now 33uF 35v EEU-FM1V330 (protection, 25V would be fine)
C807 – Original 1000uf 50v / Now 1000uf 50v (UPW1H102MHD ) (power)
C808 – Original 100uf 50v / Now UPW1J101MPD 100uf 63v (power)
C809 – Original 47uf 25v / Now 47uf 50v UPW1H470MED (power, 35V would be fine)
C810 – Original 47uf 25v / Now 47uf 50v UPW1H470MED (power, 35V would be fine)
C811 – Original 47uf 25v / Now 47uf 50v UPW1H470MED (power, 35V would be fine)
C812 – Original 470uf 25v / Now 470uf 35v UPW1W4701MPD (power)
C813 – Original 220uf 16v / Now (power) 220uF 25v UPW1E221MPD (power)
C814 – Original 100uf 50v / Now (power) Now UPW1J101MPD 100uf 63v (power)
C815 – Original 100uf 50v / Now (power) Now UPW1J101MPD 100uf 63v (power)
C816 – Original 100uf 63v / Now UPS2A101MHD1TO 100uf 100v (power)
C817 – Original 100uf 63v / Now UPW1J101MPD 100uf 63v (power)
C822 – Original 10,000uf 50v / Now 12,000uF 80v Chemi-Con ESMH800VNN123MA6 (main filter)
C823 – Original 10,000uf 50v / Now 12,000uF 80v Chemi-Con ESMH800VNN123MA6 (main filter)
C824 – Original 47uf 6.3v / Now 47uf 16v UPW1C470MDD (power)
C825 – Original 10uf 16v / Now 10uF 25v UKT1E100MDD
C826 – Original 10uf 16v / Now (power)
D701-712 – Diode 1S1555 / Now 1N4148
D801 – Diode 1S1555 / Now 1N4148
D802 & D805 – Diode 1S1885 / Now 1N4004G
D808-D811 – Diode 1S1885 / MUR220RLG (2A/200V UltraFast)
TR609-610 – Original 2SC1213 / Now KSC2383
TR701-TR704 – Original 2SA872 / KSA992 (1st differential pair / all HFE matched – shrink together)
TR705-TR706 – Original 2SC1918 / Now KSC1845 (HFE matched)
TR707-TR708 – Original 2SC458 / Now KSC1845 (HFE matched)
R709-TR710 – Original 2SA844 / KSA992 (HFE matched)
TR711-TR712 – Original 2SC1918 / Now KSC1845 (HFE matched)
TR713-TR714 – Original 2SC1628 / Now KSC3503 (Rework Legs)
TR715-TR716 – Original 2SC734 / Now KSC1815YTA
TR717-TR718 – Original 2SA561 / Now KSA1013YTA
TR719-TR720 – Original 2SC1624 / Now MJE15032G
TR721-TR722 – Original 2SA814 / Now MJE15033G
TR801, TR802, TR804 – Original 2SC1917 / Now KSC1845
TR803 – Original 2SA844 / Now KSA1015YTA
TR805 – Original 2SB544 / Now KSA1013YTA
TR806 – Original 2SD234 / MJE15032G
TR808 -809 – Original 2SD400 / Now KSC2690AYS
VR701-VR702 VRs (5K) / Now 3386F-1-502LF
New Panasonic Relay (Direct Replacement)
Some Before Pics:
Bottom cross members / supports include ground pads. I created some additional ground straps / wires after these were removed.
Input Pair - Replaced.
Some Crazy Leg Action
As you see the original filters were 5 lug pattern - anyways no problem to get them to work.
And thank you for your comprehensive list, its been very helpful!
Super Noob
Super Member
Preference.
Snow_
New Member
Hey,
About a month ago... was able to pick up two CRs - both were non-working. Have much gear and only Yammie was a DSP-A1 (beefy) which was included with a purchase of some Infinity RS-IIIb. I really liked it, but I moved it down the road to keep with the silver theme. These were in non-working form and priced right and with discrete outputs (non-darlington packs), so I was game to give 'em a run.
Rebuild - First Up = CR-820
After some time, I found a trace that was scraped / comprised in the power supply. Was able to get out of protection. Was by no means the first one in this unit. Some fusible resistors where changed.
For sure the traces seem (to me) very delicate compared to a lot of the units that I have worked on. Lots of stuff is going on the power supply / amp board to say the least. The schematics and service manuals are not as well documented either. Regardless, I proceed.
I followed your great guide and once I finished turned the amp on and all good!
Except I turned it off and then one minute later on again and suddenly I have a resistor burning rapidly :///
(The one labeled 58mA 68ohms) Can you point me to what the fault could be, it seems you are experienced.
The fact that the resistor is labaled gives me hope, that its meant to burn up, to protect the rest of the circuit.
Kind Regards
Konrad
Edit: I believe I have found the problem and can fix it myself, also happy to report I am not to blame, previous owner had messed up some traces and when replacing TR721 I had shorted the open lines, first the resitior took the fall, then TR721 started heating up rapidly. Ill replace the parts and try to go around the messy pads and scrapped open traces.
Attachments
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Is there a good available substitute for the 2SC1628?
Most search end with obsolete. Can someone recommend a replacement?
Thank you
Most search end with obsolete. Can someone recommend a replacement?
Thank you
Thanks. Checked on Mouser and digikey and both out of stock for the ksc3503. I know i will have to bed one of the leg since pinout is different.