Project: Yamaha CR-820 (Rebuild)

[Super Noob]

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.

 

[Super Noob]

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.

 

[Super Noob]

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).

 

[Super Noob]

Tone Control Board (NA06909-2)
C601 – Original 10uF 16v (signal path) / Now 10uF 25v (NICH UKL1C100MDDANA)
C602 – Original 10uF 16v (signal path) / Now 10uF 25v (NICH UKL1C100MDDANA)
C609 – Original 47uF 6.3v (decoupling) / Now 47uF 16v (NICH UKA1C470MDD)
C610 – Original 47uF 6.3v (decoupling) / Now 47uF 16v (NICH UKA1C470MDD)
C611 – Original 47uF 16v (signal path) / Now 47uF 25v (NICH UKL1E470KED)
C612 – Original 47uF 16v (signal path) / Now 47uF 25v (NICH UKL1E470KED)
C613 – Original 100uF 6.3v (signal path)/ Now 100uF 16v (NICH UKL1C101MPDANA)
C614 – Original 100uF 6.3v (signal path) / Now 100uF 16v (NICH UKL1C101MPDANA)
C621 – Original 100uF 16v (signal path) / Now 100uF 25v (NICH UKL1E101MPDANA)
C622 – Original 100uF 16v (signal path) / Now 100uF 25v (NICH UKL1E101MPDANA)
C629 – Original 10uF 35v (decoupling) / Now 10uF 50v (NICH UKTH100MDD)
TR601-606 – Original 2SC1917 / Now KSC1845
TR607-608 – Original 2SA844 / Now KSA1015

Before:

 

[Super Noob]

TUNER C. BOARD (NA-06915-1) / Phono
C101 - Original 100uF 6.3v / Now 100uF 16v (NICH UKA1C101MDD)
C111 - Print 10uF 16v Found 3.3uF 50v / Now 3.3uF 50v (WIMA MKS2C043301K00JO)
C112 – Original 1uF 50v / Now 1uF 63v WIMA MKS2C041001F00JA
C113 – Original 1uF 50v / Now 1uF 63v WIMA MKS2C041001F00JA
Cxxx IC103 - Original 100uF 6.3v / Now 100uF 16v (NICH UKA1C101MDD)
C116 – Original .22uF 50v / Now .22uF 63v WIMA MKS2C032201B00JA
C202 - Original 100uF 6.3v / Now 100uF 16v (NICH UKA1C101MDD)
C203 - Original .47uF 50v / Now .47uF 100v (WIMA MKS2D034701E00JI)
C204 - Original 10uF 16v / Now 10uF 25v (NICH UKT1E100MDD)
C207 - Original 10uF 16v / Now 10uF 25v (NICH UKT1E100MDD)
C208 – Original .22uF 50v / Now .22uF 63v WIMA MKS2C032201B00JA
C211 – Original 1uF 50v / Now 1uF 63v WIMA MKS2C041001F00JA
C212 – Original 220uF 16v / Now 220uF 25v (UKA1EE221MPD)
C219-C220 – Original 1uF 50v / Now 1uF 63v WIMA MKS2C041001F00JA
C223 – Original 220uF 16v / Now 220uF 25v (UKA1EE221MPD)
C224 – Original 1uF 50v / Now 1uF 63v WIMA MKS2C041001F00JA
C302-C303 - Original 10uF 16v / Now 10uF 25v (NICH UKT1E100MDD)
C304 - Original 33uF 16v / Now 33uF 25v (NICH UKA)
C305 – Original 1uF 50v / Now 1uF 63v WIMA MKS2C041001F00JA
C309 – Original 1uF 50v / Now 1uF 63v WIMA MKS2C041001F00JA
C311 – Original 10uF 16v / Now 10uF 25v (NICH UKT1E100MDD)
C318 – Original 3.3uF 50v / Now 3.3uF 50v (WIMA MKS2C043301K00JO)
C319 – Original .1uF 50v / Now .1uF 50v WIMA MKP2C031001F00JS
C320 - Original .22uF 50v / Now .22uF 63v WIMA MKS2C032201B00JA
C321 - Original 100uF 6.3v / Now 100uF 16v (NICH UKA1C101MDD)
C401 - Original 10uF 16v / Now 10uF 25v (NICH UKT1E100MDD)
C405 - Original 33uF 16v / Now 33uF 25v (NICH UKA1E330MDD1TD)
C407 - Original 10uF 16v / Now 10uF 25v (NICH UKT1E100MDD)
C411 - Original 33uF 16v / Now 33uF 25v (NICH UKA1E330MDD1TD)
C416 - Original 10uF 16v / Now 10uF 25v (NICH UKA)
C501-C502 - Print 4.7uF Found 10uF 25v (LL) / Now 10uF 35v (UKL1V100KDDANA ) Phono
C515-C516 - Original 470uF 6.3v / Now 470uF 16v (NICH UKA1C471MPD1TD)
C517-C518 - Print 4.7uF Found 2.2uF 50v (LL) / Now 2.2uF 50v (WIMA MKS2C042201K00JC00)
C519 - Print 47uF 35v (LL) / Now 47uF 50v (NICH UKL1H470KPD1TA)

 

[avionic]

I would have slide a small piece of heat shrink tubing over one of those crossed leads.

 

[Super Noob]

The tuner works well and alignment was good. Just recap.

Some LEDs... keep in mind there are two pairs of lights wired in series.

It should also be noted that all the controls (pots and push buttons contacts) were soaked with D5, then worked, then flushed with F5.

The bias was set to 8 mV per the service manual. Offset improved by miles from my first measurements in the 30 mV to less the 9mV on one channel and less then 5mV on the other channel - not too shabby. (no offset adjustment).

Hope these list help someone... they are not 100% verified, but a good start compared to what I have seen. Keep in mind I have stock of all the caps except for the main filters, the large voltage zener, and relay.

My count worked like this (~):
88 Electro Caps
6 Fusible Resistors
2 Variable Resistors
1 Rectifier
22 Diodes
40 Transistors
1 Relay

 

[Super Noob]

Finishing Up:

Picked up some NS-225s last weekend... I recapped them yesterday. The Yammies are playing together.

 

[Super Noob]

I would have slide a small piece of heat shrink tubing over one of those crossed leads.

Am a leg bender from way back... good tip Avionic. I was deciding to keep the 2SD234 (TR806), but it would introduce noise after it warmed up (leak). I replaced with MJE... but since replacement I get a .25 second sneaker on gym floor squeak (from the speakers -- not loud just noticeable) when I power off the unit & I don't disengage speakers. Anyways thanks for looking at my build. I read plenty of your posts along the way.

Hope it helps someone with a future recap.

 

[avionic]

but since replacement I get a .25 second sneaker on gym floor squeak (from the speakers -- not loud just noticeable) when I power off the unit & I don't disengage speakers.

When you modded the lamps with LED's you change the protect relay " reset " timing. Relay contacts stay closed longer than they should.And your hearing the power supply collapsing.

 

[Super Noob]

Was around the same time... but I disconnect them thinking they could be it (and still got the sound). Let me think about it.

Thanks again.

 

[avionic]

If you have any burnt out incandescent lamps it will do the same thing.

 

[Isaac C.]

Wow, nice rebuild log! Looks nice and clean on the inside! I'm about to recap a Hitachi HA 610 this week, should be fun as I enjoy soldering.

 

[Super Noob]

Went back in and changed the LED resistor setup.... timing is right now (no sneaker on the gym floor sound on turn off).

Went ahead and changed the dial LED illumination to green. Tell you what = nice looking and sounding set.

 

[Super Noob]

Forgot to add = big thanks to our Yammy Guru = Avionic for guiding me into the fix.

We are extremely lucky to have you here... thanks again my friend.

 

[Greyfixer]

Great rebuild and awesome write-up!

 

[avionic]

Great rebuild and awesome write-up!

Ditto...

 

[Brett027]

Awesome writeup. Hope you don't mind if use this to help with my rebuild of one of these things. You are correct about the documentation not being very good. I do have a question.. So I see transistor numbers on the silkscreen portion of the boards. However I don't see where you got the numbers for the caps. I would love to know the locations of all of the caps, diodes, and transistors.. Some sort of map or something. Otherwise it will be pull one part out and put one in sort of thing. Which might not be a bad thing anyway. LOL

 

[avionic]

. Otherwise it will be pull one part out and put one in sort of thing. Which might not be a bad thing anyway. LOL

Exactly..The only way to do it..Without having to trouble shoot issues that could have been avoided.

 

[Olliedazzle]

Just want to say this write up and parts lists helped me a ton on my dad's cr-820. A couple output transistors shorted and took down a slew of transistors and the 68 ohm fuse resistors right before reaching the coil/relay section of the board. It was helpful to trace the DC voltage from those backwards to find the culprits. Thanks avionic and Super Noob!

PS for the longest time, I couldn't figure out why the face plate would feel like it was grounding a small voltage whenever I touched it. I figured it was because it was old and 2-prong. Turned out replacing the burnt out lamps resolved that, there must have been a small voltage leak with nowhere to go when they were out. Also took me a while to figure out the Red and White wires to the lamps did not correspond to +/- and that lamp 3 and 4(the tuner) were the ones in series parallel to 1 and 2... I should have taken a closer look at the schematic before approaching all that