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Project: Yamaha CR-620 (Rebuild)

Super Noob

Super Noob

Super Member
Now on to the 2nd on my non-working Yammies.

CR-620. Typically stay away from the lower WPC units = but it was essentially like a BOGO deal relating to their non-operational status - then add in discrete outputs and plenty of good things said about the 620, so I am in.

pU3ca1EHo-QVMmcdak7ymkDuLxbLwZHFh4gIBM9ETNxzaEQl_-220BIhlmZFAMtzvvHZLIJliJFGRhph6EBgnJv75E4vu1lCxA1T3p5AzXG7ELwrTLorbRAkz7rkT7y0uc8hpaFe75silkvNGle8QYUuE1-_FyHOpA2dZqNhLY6BQtRmqyaAbWsHFhqyT9aRKoF0Ovksveo8tgflUgC6RMNywvs__PReA08qxaEhfZNd9kZO19_ZIex55JEpF7l_zbXFpAFZ-GirGzJnRoWfdxhW2c4243ephGqsndXUvzPMTTSECS8Dd4-4VfRpq_25HI2sSCli0sJ55iN6iwAJcbAP2s39Nh43Ha_HZ1Rl3UjhM7ShZQXXFvwCUUQ7A6TmTDXb4tdDFTMfHuwF5p5x8dECtSjHXLEL7D-9AzwqqHcTuxfSbC_9xinrdcglx8KsQg2b-1zUscGymyThS7wrEucBYxoyRW3_XVvF9LFFZLT76iYlMqcOGzAN8_i5qP8Ldt7RLfowWXrD_vX6vi1yf-XR8qcJXvkw0aL9IQNCvzajMPgtsli_ruHnfjiBeVY912u3tZKfompGmfyaZpcgvIXFARCVYm7KGOzYlj4UdS6eZ3mTfKqWHFdTgQMmpwyD2e5Q3ZcA1QwydIdtfAaXWHKf88hzb9-eoRF9ojgd4DEkt4Occq4yTw=w1147-h861-no


Guess it needs to be said again, the board drawings in the parts manual and part lists are subpar in regards to the other units that I have worked on; nonetheless, I proceed.

In less than 2 minutes the unit is up and running - simple re-flow of TR802, as noted by many previously TR802 runs hot and has been known to compromise its solder joint. After that... time for the rebuild.

A fair case could be made for the retaining the small transistors / diodes = but I changed them anyways.

Here is the cap summary and semi(s):
WORD:
https://drive.google.com/file/d/1MbJQ3PtP3vk5dMfZYBXn60ckIddioQID/view?usp=sharing
PDF:
https://drive.google.com/file/d/1-u_GFIZnGIbmTEpOhcWYtOW034LTxHis/view?usp=sharing
 
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Main Power Board / Amplifier (NA06922-1)
C802 – Original 1000uf 50v / Now 1000uf 50v (UPW1H102MHD ) (power)
C803 – Original 100uf 50v / Now (power) Now UPW1J101MPD 100uf 63v (power)
C804 – Original 47uf 25v / Now 47uf 50v UPW1H470MED (power, 35V would be fine)
C805 – Original 470uf 25v / Now 470uf 35v UPW1W4701MPD (power)
C806 – Original 47uf 25v / Now 47uf 50v UPW1H470MED (power, 35V would be fine)
C807 – Original 47uf 25v / Now 47uf 50v UPW1H470MED (power, 35V would be fine)
C808 – Original 220uf 16v / Now (power) 220uF 25v UPW1E221MPD (power)
C809 – Original 100uf 50v / Now (power) Now UPW1J101MPD 100uf 63v (power)
C810 – Original 100uf 50v / Now (power) Now UPW1J101MPD 100uf 63v (power)
C811 – Original 100uf 63v / Now UPW1J101MPD 100uf 63v (power)
C812 – Original 100uf 63v / Now UPW1J101MPD 100uf 63v (power)
C813- C814 – Original 22uf 25v / Now 22uF 35v UKL1V220MEDANA
C815 – Original 4.7uF 35v / Now 4.7uF 50v UPW1H4R7MDD
C816 – Original 33uf 16v / Now 33uF 35v EEU-FM1V330 (protection, 25V would be fine)
C820 – Original 47uf 6.3v / Now 47uf 16v UPW1C470MDD (power)

C825 – Original 10uf 16v / Now 10uF 25v UKT1E100MDD
C826 – Original 10uf 16v / Now 10uF 25v UKT1E100MDD

D701-710 – Diode 1S1555 / Now 1N4148
D802 – Diode HZ-30 / Now 1N4751ATR (30V 1W Zener)
D803 – Diode 1S1885 / MUR220RLG (2A/200V UltraFast)
D804 – Diode HZ-12C / Now 1N4743ATR (13V 1W Zener)
D805 – Diode HZ-12C / Now 1N4743ATR (13V 1W Zener)
D806-D809 – Diode 1S1885 / MUR220RLG (2A/200V UltraFast)
D810 – Diode 1S1555 / Now 1N4148
D811 – Diode 1S1885 / NOW 1N4004G (1A/400V)

C701-C702 – Original 47uF 6.3v (signal) / Now 47uf 25v UKL1E470KEDANA
C705-C706 – Original 220uF 6.3v / Now 220uF 16v UKA1C221MED
C715-C716 – Original 47uF 35v / Now 47uf 50v UKL1E470KEDANA
C721-C722 – Original 1uf 50v / Now 1uF 63v WIMA MKS2C041001F00JA
C735-C738 – Original 1uf 50v / Now 1uF 63v WIMA MKS2C041001F00JA
C743-C744 – Original 1uf 50v (BP) / Now 1uF 63v WIMA MKS2C044701M00KO

TR701-TR704 – Original 2SA872 / Now 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)
TR709-TR710 – Original 2SA844 / Now KSA992 (HFE matched)
TR711-TR712 – Original 2SC1918 / Now KSC1845 (HFE matched)
TR713-TR714 – Original 2SD438 / NOW KSC2690AYS
TR715-TR716 – Original 2SC1918 / Now KSC1845 (HFE matched)
TR717-TR718 – Original 2SA844 / Now KSA992 (HFE matched)
TR719-TR720 – Original 2SD438 / NOW KSC2690AYS
TR721-TR722 – Original 2SB560 / NOW KSC1220AYS

TR802 – Original 2SD234 / MJE15032G
TR803 -TR804 – Original 2SD400 / Now KSC2690AYS
TR805, TR806, TR808 – Original 2SC1918 / Now KSC1845
TR807 – Original 2SA844 / Now KSA992
TR809 – Original 2SB544 / Now KSA1013YTA

VR701-VR702 VRs (5K) / Now 3386F-1-502LF

NEW RELAY HC2-HP-DC12V-F

FYI - the main filters I bought at the same time as the CR-820 purchase. Upped from 6800 to 8200uf, upped the voltage a level, and 105 degrees = however, to my surprise they were bigger than what was used in the 820. I ass-u-me that they would have similar power supply areas as they used the same case... WRONG. Anyway they were not too much bigger, and I easily made them fit = no bubbles / no troubles.

Japan Build Unit:
AXhu7ZXsZFARv-GULvpQ8fTvcdMbGhepAdX6hdZ-T0k1CghJstWXXA2IziyG9uxOdDoq0SHgZvF9B-azb613GKMT9lOD7oNyKTbpvtprVdyMhrKUhFSUo07nsQSHqpdi_Wn_g7jnxA=w1175-h881-no


Before:
bmSKaUlBpDgrb1BNsjAJCL1kvtZIgh8Knbv5kBEF7L1UIHk91wE2o8eerIB5BXAzGzNKH-RTWig32jMI7N9O0otDzGcsIF1EHhfQh5sLgN7YSUyKpgSM95hoAJxne36ShVgRdy0CIw=w661-h881-no

FU-DCpAZv7eiI_pBpriAwGn1DRvjJkO4XtrUp50Sd6GrVqhLWV_gondJ2eWkZPya-TmgmDVxZsXIIVpgYJfhTY39VAQzZBBbYXoR89vVcTMUJsYq_sqvmCuOK63Qo2Ls9WHAmTcfiQ=w1175-h881-no


8W3o1M3ZHS2zgqMjgZw0p5dQHxBurBuTDvieqh2Z38EDyXqPT15eqWouyf66qi6lIPxvZIge08qZoL8HSmzl-aOLpysZOh_gK2mMNbYcAFqhrwGjzPy-A8B0sXwxykfEK6vWtQ8H1g=w661-h881-no


After:
XwtuINcuPZ0IVUNDKSLUoWtxLSkgmQY7Isi3L4LhOEu-yODhpmY4y41zABZSJOfLent-CECr0RS9-yzkQz90yJtD7CD30wbDf70QrMb4WtRXSQQt6Hy-DHKTnEhi2XwaD2zwCLqZIw=w1175-h881-no

w9ON4pnJ80ywt9lZN_fJxxCKYi0JXnyQVaj_a7lYft2AlD6b3rhYlk7-DdvsxNsPubw4VsOj0I9fKRpQVBFR3aVLjJQEbWPkldDXjmjWcesfjURrHIECexSVzry0_Gf5CKCSyNHTGQ=w661-h881-no
 
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Tone Control Board (NA06918-2)
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)
C619 – Original 100uF 16v (signal path) / Now 100uF 25v (NICH UKL1E101MPDANA)
C620 – Original 100uF 16v (signal path) / Now 100uF 25v (NICH UKL1E101MPDANA)
C631 – Original 10uF 35v (decoupling) / Now 10uF 50v (NICH UKTH100MDD)

TR601-606 – Original 2SC1917 / Now KSC1845
TR607-608 – Original 2SA844 / Now KSA1015YTA

The controls pots didn't sound bad but went ahead and gave them a dexoit D5 bath, soak, work like spare rib, wait, flush with dexoit F5, wait, work like spare rib = good as new. In addition, I cleaned the push button contacts.

Before Picture:
B5THBc0b_VnhCLwiNwieIb4cv-N14dZak90AzqmjllABjQfCYaV9_KZHcaxkQXgWPoJ573zSRoCKFomkgnrSrtEBlx1ebGZK_1p9lrAWunFGdYyyEQAa8jrSVhi-Ah8viqOu8CLXMQ=w661-h881-no


After:
cYE9smGAlHkBbI7vUGLKYsMxgveXE-Lq8WBOVyBUdTIuICTZINMc12pD6Q1i5PbxCizDAZjsKfPlYIDn0w8nXcCP6S1sdtjBWkIiG1rNFNovgYvAZGNe_taPk4-hSIO6CTt33LEUXQ=w661-h881-no

uhCzCjpMaDvtzbnaOsx5_3I-FvPjDcv5PfWwvee3Te7M4UyJiw-Z_fhSm5fzRKzb1dzaH8Jl0PL76cktVAR-hd00vM1LFf3NWTzCrbCsOv_H5N0b-FZgu7WyN37FR_lb9edB0r-Ttg=w661-h881-no
 
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TUNER C. BOARD (NA-06923-1)
PHONO
C501 – Print 4.7uf 25v found 10uF 16v (LL) / Now 10uF 25v (NICH UKL1C100MDDANA)
C502 – Print 4.7uf 25v found 10uF 16v (LL) / Now 10uF 25v (NICH UKL1C100MDDANA)
C517 – Print 4.7uf 35v found 2.2uF 50v / Now 2.2uF 63v WIMA MKS2C041001F00JA
C518 – Print 4.7uf 35v found 2.2uF 50v / Now 2.2uF 63v WIMA MKS2C041001F00JA
C515 - Original 470uF 6.3v / Now 470uF 16v (NICH UKA1C471MPD1TD)
C516 - Original 470uF 6.3v / Now 470uF 16v (NICH UKA1C471MPD1TD)
C519 - Print 47uF 35v / Now 47uF 35v (NICH UKA1V470MDD)

TR501-TR504 – Original 2SC1917 / Now KSC1845 (HFE matched)
TR505-TR506 – Original 2SC1213 / Now KSC2383

TUNER
C112 - Original 1uF 50v / Now 1uF 63v (WIMA MKS2C041001F00JA)
C113 – Original 10uF 16v / Now 10uF 25v (NICH UKT1E100MDD)
C114 - Print 47uF 16v / Now 47uF 35v (NICH UKA1V470MDD)
C115 - Original .47uF 50v / Now .47uF 100v (WIMA MKS2D034701E00JI)
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)
C223 - Original .47uF 50v / Now .47uF 100v (WIMA MKS2D034701E00JI)
C224 - Original .47uF 50v / Now .47uF 100v (WIMA MKS2D034701E00JI)
C207 - Original 10uF 16v / Now 10uF 25v (NICH UKT1E100MDD)
C208 – Original .22uF 50v / Now .22uF 63v WIMA MKS2C032201B00JA
C210 – Original 1uF 50v / Now 1uF 63v WIMA MKS2C041001F00JA
C211 – Original 220uF 16v / Now 220uF 25v (UKA1EE221MPD)
C212 – Original 220uF 16v / Now 220uF 25v (UKA1EE221MPD)
C302 – Original 1uF 50v / Now 1uF 63v WIMA MKS2C041001F00JA
C303 - Original 10uF 16v / Now 10uF 25v (NICH UKT1E100MDD)
C306 – Original 1uF 50v / Now 1uF 63v WIMA MKS2C041001F00JA
C312 - Original .22uF 50v / Now .22uF 63v WIMA MKS2C032201B00JA
C313 – Original 3.3uF 50v / Now 3.3uF 50v (WIMA MKS2C043301K00JO)
C401 - Original 100uF 6.3v / Now 100uF 16v (NICH UKA1C101MDD)
C402 - Original 10uF 16v / Now 10uF 25v (NICH UKT1E100MDD)
C406 - Original 33uF 16v / Now 33uF 25v (NICH UKA1E330MDD1TD)
C410 - Original 33uF 16v / Now 33uF 25v (NICH UKA1E330MDD1TD)

CONTROLS
C671 – Original 10uF 25v (LL) / Now 10uF 35v (NICH UKL1V470KPDANA)
C672 – Original 10uF 25v (LL) / Now 10uF 35v (NICH UKL1V470KPDANA)
C677 – Original 2.2uF 50v / Now 2.2uF 63v (WIMA MKSC042201K00JC00)
C678 – Original 2.2uF 50v / Now 2.2uF 63v (WIMA MKSC042201K00JC00)

Here is the before:
5sfFkGYf5ceTptLr5NcQJRuGy7Ozr3mxuBVrkrkPHTcUHog8MHT94TGtbHElBKal8lnG9Y-WJxxZzMRRNdfAnX1I-LdrvDPSCh9MbMZGSyZUuo980CNOjrE66HiBSivtzIBeL8KNPQ=w661-h881-no


Y2qH31-rHT9Bi_s4VspQsjs3SEMUKv0Aa9meI3W-IAf_40Qeok6n26y5LY_iyV4wFIwsE9njq_oZMcYGlKrSs4sA5bTSuKHuA0e0bRyoukHwMgK7lZ02b7gvI5LwQnKYhgVM9t6BFA=w1175-h881-no


Afters:
wf9xd8Ddvh2PwXNegfYSe0rp-mI73ICnCIJV_NsR96sgZshR5QWUGx_aqKcbCOF05U2W3-EKBS7FTqk0e8XzJvVSlnsuJZTMEPGx43JNPDhGr-irD-eYZJjBrUYXVqWVz0X7KJVogw=w661-h881-no

QETl327_bKU1mx8X4VOkPKrSizoLaMtl0CiUAc_DDsFO00IqAIp6a5m-mDvCdiwGuWVvablcjMriDNd2AvwJWd87QlvDgoBDSxhtulL0olujcNpIHCdI3oxYYyOosUoTowOifeBKIg=w661-h881-no
 
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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.
GSCo4h5QM39k88ql_P9VWRiuUQ5LUAR0MGq70kMMYRfBtomL43aFuiSii4uab3zqkL3VfudOoIbaC0KVnsz5nr5kCe3xDI1M-cG_TPbm8yRphXxYUk6_dp2i07m1Ha14C-zi3cX67A=w661-h881-no

M3DhVDUghUWfoBKXNRwfFNQNDBWxH5ULBuA0Fe-U-KnLyo5RutRx6JXqqmB1kvSwaE_6jSesB9DAPMBzxuGs_L0IzX45FbmTYl0MaizMU5Oeh1qqZR31TCjf51s6z8gKWOgtZXfNTQ=w661-h881-no
 
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Finishing up.... with the new match pairs and semis the DC offset was less than 10mV on one channel 5mV on the other channel = very good indeed.

Let her warm up and dialed the bias to 7-8mV on each channel per spec.

Summary of Item Replaced:
44 Transistors
22 Diodes
2 Variable Resistors (sealed)
79 Electro

Here are some pics of the final boards and parts:
PIb4RiNSNLqdJvMMEhLoj4lPyKiEaOnkXE2Dr4m5yNRd8Lu6snl0cJNnQ5-bnDXKyI7p1-apcYkcp6OFKDYzB_13HFFJYLOQ4tyEkZu9gqox_L234yc44ZvL3a_rwRA80oXacMaPFg=w661-h881-no


VwXhkO3lm-sM1xszhaOaKVnR8cJWPygWfsaGVjB3YUFO2vi98s0LUkWUAe0beHEEXQqnq71H2Vo9rzL6RiE6sB06m7FAHZWfvYCwIZvKjoeu2JwMOven7uoLfQws4ppLuk012zoqaQ=w1175-h881-no

auLeY-ahk2sQ_Ol_lM-uX2PSL5NPT3evBApZ1YOA4RtDpuY4QWlBNZ29PSoI56Tlt9MuwCDQ3aG_bdjkyEUOIjbrdxem8ZlEpDNdM3ZJ-oyCi4qRvHzwP_bmUHDZ_0U_-_xTNF5d6w=w1175-h881-no


I like adding ground straps to the board network.... there are two more that are not shown under the center bar. Here is shot of the bottom (after complete):

Y1shNZ9w17EskTkheZXTPYi_E9Kfl2-uzA1mmb8vrAEJBN0jTpGKvzNIvsWXtL5pw24NzHAd-RGeaDtvn8Et4ydnXk8LOEkImE9XJvvq7RK07f_B0Wd6VCDInya1vInxNXH7mWsP7w=w661-h881-no
 
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Some Final Shots:

jCzOU7MblO5LSmnz1EkyNUV5cPO6z2ieJt8KUqUEIlUxdkx5TfXXEkqGW05U11tFLxW19iVTnOHJY81GxJEDcQGSEvEy5wFnBa3Ek4zL3Wv6n1FLw0JnqstPFpfr77uFDoxEAjZW0rbzt-T76hiG_35CAjIJeIdF_zDJU5r4wemQsIuyvCc8mf8ar19fNGxzj3Yekk0douYEgiut50wHyRHRqwtvshs_dR2rJnAdGf0rnKuoJh_VfE5eJv1FvW9OdSlLNrPy-tbj2r0yfKSiWLUun1-5qEgxFcbT8Oib_YGzMYpeXCVOHJIdTcJO6UxoRMqPG11GeD9rfDPW6-l3uzcQOEbI_j8Z4-MjRv9qDaRFLeoR2c3IKuS3n2jlRA3hpDAUGBDX4yBbyKFhiEjZdUi8NvCorpfypYX0kMP8Rq_JKuvXaS1PKsFwEsdq-3P_5gPQamTxPScoCTMdZPN3DNeJiStDVr6SoeCsCofDeo7XLfqALicQgTvetS1G6__ATXn4kyrhGbhSWQgcehk6wLSUb6FEFUOG4PcyG2PV4GXOYKUR1a9ZSlIW81O9Vcg1hgWjWyHS1f_w78SfUhqblWBvt73wMgLw70O-AsgVl6wPQbu7gR_IHdev9tGqsgOoXVxNwsgeWh5fhAJwhrVkRGzbXx63rLbdWmuy8EloehWK1Y-fOO1K-BYMa6g8DmSi9tEXrX_p=s1147-w1147-h861-no

mnTJjlCp-qd0mGSplgfmsWGa2RUQgKWXwA9krF4R5weNfdW05Lq-2W-BPqK3nSRV5ycfrhi-jPDSnFtzAav9Tq4pm5W6Sb2dN-ddZM6oUFic-pY4av4xJhskpPOUu2fXqjzGt8b6-bss0Z0LWjgp8PddBlmfWhwaLLTlnRFLaSla2zy0IOo7-b5RlgSKOomGcZubbLBFx_LngMEYP6YHxz_B1tWwCbOQXfQBU4pbs3HJgHf386yfBauTBS6Tf77zJzZXWt3vfolPoarmJApzHk1es6hKHXB7ocS6FJX4PTM7flqeXg31sgmT7-XRawS7K-aa4pMGnK7P80aveXNJvLMHbh5SsIIOjkG3buBOgctJVsv3V_PnzT6StuJqnAyAbt1MLpitd7I5vwhJCwGtldtq6t3teur9z6a6H7tFFteoy2gjTU1huIsWx1FC8IHVOfREo_Zg4YRs6YU6ekEwATJIgLFAgjVY-V9GHCJokM-Aqx_N-iecxK9O2uHp5CRtmsdms-OsQQy0m7cMz2MvPVfZGOM2LhQZ1taarYkasbMp69qHRHylKzcBPQCxiVdTx9WVujDdJzMz602cvRoYFHixRHYQGZTJw9nWY6bdft8Mdp0_-4vp-sx8oPrSXyMA5wL3txlaraKC6ixX3nyYdG2Bw-cAt3LKDo9_GHOOPWD5IpckFl91qy40A_MAdAmwj1yQx-Q9=s1147-w1147-h861-no


qgjouK6bEvkr2h4QS4Tpv-oTh_Fo9ovSv8SGIb608bOAGDr1HW9dncjXTGtpZW5uBCLrbMzvA-GxLMmvSi2lwPvBiVfZUPzYFQdNj9IINcXWIC-jH-1Wm4U8qNVJ7S3A8bTWMgCsuw=w1175-h881-no



Here is what I hooked her together with - not much information on these - NS225 (late 70s). I recapped the crossover with some Bennic films and new bio-polor electro & cleaned the pots. The axial electros measured really high... anyways new caps in and playing with 1st cousin CR-620. Like others have said about these CRs = clear, transparent, sparkling (think that is just about right).

Will have to admit a 30WPC unit this is worth the effort. Hoping to inspire the next person to rebuild this unit!

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Super Noob said:
Now on to the 2nd on my non-working Yammies.

CR-620. Typically stay away from the lower WPC units = but it was essentially like a BOGO deal relating to their non-operational status - then add in discrete outputs and plenty of good things said about the 620, so I am in.

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Guess it needs to be said again, the board drawings in the parts manual and part lists are subpar in regards to the other units that I have worked on; nonetheless, I proceed.

In less than 2 minutes the unit is up and running - simple re-flow of TR802, as noted by many previously TR802 runs hot and has been known to compromise its solder joint. After that... time for the rebuild.

A fair case could be made for the retaining the small transistors / diodes = but I changed them anyways.

Here is the cap summary and semi(s):
WORD:
https://drive.google.com/file/d/1MbJQ3PtP3vk5dMfZYBXn60ckIddioQID/view?usp=sharing
PDF:
https://drive.google.com/file/d/1-u_GFIZnGIbmTEpOhcWYtOW034LTxHis/view?usp=sharing
Click to expand...

Nothing wrong with a mid-power unit.
 
Is there anyone in Houston that can rebuild my CR-620 to this standard? It has power, lights, tuner seems to get signal, but no sound..
 
The OP is a DIY then he/she can go all out. It is kind of unnecessary but DIY only pay for the parts which is about 1/10 of the cost of the total (parts + labor).
 
IMO, the CR-620 is a wonderful low power receiver. It needs a full recap because there was something about the caps or cleaning process used that causes them to go bad at a much higher rate than normal. Other than that, I'd never replace the semiconductors unless some were actually bad. You can't get that good a selection of leaded parts these days and might actually degrade the unit by changing parts unnecessarily.
 
ConradH said:
IMO, the CR-620 is a wonderful low power receiver. It needs a full recap because there was something about the caps or cleaning process used that causes them to go bad at a much higher rate than normal. Other than that, I'd never replace the semiconductors unless some were actually bad. You can't get that good a selection of leaded parts these days and might actually degrade the unit by changing parts unnecessarily.
Click to expand...
I am new to this and this would be my first undertaking of something of this scale. When you says just replacing the caps which ones are you referring to. I printed this list off just gotta figure out which ones to buy? I'm looking these parts up and alot of them are obsolete.
Thanks in advance
 
Replace just the aluminum electrolytic capacitors. Be careful with lists- check what's actually in there when you replace. I vaguely remember that the caps are pretty easy, except for a few small ones at the very edge of the board.
 
There is also a bar that needs to be removed in the middle to access a few legs. Its no big deal. The purple caps are always usual suspects.
I had DC ripple on mine, but replacing the main filters solved that. Maybe start with just the power supply section. Test. Then proceed onto the next section.
 
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