Just for fun I aquired a Nakamichi SR-4A receiver. I own quite a few Nakamichi cassette decks, but no other Nakamici device. Coming across this receiver, I thought it would be a nice gadget to play with...
It works just fine in all mods, from Phono (both MC and MM), to tape. The only things which are not working are the Tuner, the Display and anything related to this one. The remote control does not work either.
I assume it has to do with the power going to the tuner and display where the remote sensor is too.
I checked all fuses and they are all fine. Since I was not able to locate a service manual, I have nu schematics; that would be a step in the right direction but if any one experienced the same issue, please share.
Thanks
It works just fine in all mods, from Phono (both MC and MM), to tape. The only things which are not working are the Tuner, the Display and anything related to this one. The remote control does not work either.
I assume it has to do with the power going to the tuner and display where the remote sensor is too.
I checked all fuses and they are all fine. Since I was not able to locate a service manual, I have nu schematics; that would be a step in the right direction but if any one experienced the same issue, please share.
Thanks
This site has got service manuals, but it requires you to register first.
Download the Nakamichi SR-4 service manual for free - Hifi Manuals
Download the Nakamichi SR-4 service manual for free - Hifi Manuals
Easy.
open unit.
test to find faults.
repair faults.
close unit.
Anything else you'd like explained ?
Or, My favorite.
if your unable to perform basic tests, safely, then take to someone that can...
easy SR-4A
Orange light indicates fault.
it is difficult upsidedown power board measuring proper dc feeding voltages, toroid and power board upsidedown dismantled, key voltages threesome 5.6, 10 (12), 30 dc.
Orig discovery 2amp fuse open and power board sponge underside leaking energy out of system. Replcd 2amp pigtail fuse, zd403, q403 and q402. (Zener6.8, c945, d1406)
Yet persists orange power light.
Checked bridges okay out of circuit (three).
Gotta save this amp cause rare.
Orange light indicates fault.
it is difficult upsidedown power board measuring proper dc feeding voltages, toroid and power board upsidedown dismantled, key voltages threesome 5.6, 10 (12), 30 dc.
Orig discovery 2amp fuse open and power board sponge underside leaking energy out of system. Replcd 2amp pigtail fuse, zd403, q403 and q402. (Zener6.8, c945, d1406)
Yet persists orange power light.
Checked bridges okay out of circuit (three).
Gotta save this amp cause rare.
I had the same problem on a SR-4E, fixed it by replacing Q404 and D414. Used a KSA733 and a 1N4002. (also replaced Q405 while I had it dismantled, but it was probably not needed.)
It booted up into solid green power light.
Replaced q403, 402, 404, 405, 406, zd403, 404, c427, retraced copper patina compromised of sentinel ac sense between cn20 : t2
But bootup takes about seven green blinks before solid green engages consistent without fault.
But tuner display illuminated dim, why? Should change 7812 regulator on power board?
Or could it be nte ecg equivalents of replaced discretes above are actually not compatible regardless of blessed equivalency?
BTW, on powerdown, before solid green indication extinguishes, orange light very very short duration seen, is this bad news?
Replaced q403, 402, 404, 405, 406, zd403, 404, c427, retraced copper patina compromised of sentinel ac sense between cn20 : t2
But bootup takes about seven green blinks before solid green engages consistent without fault.
But tuner display illuminated dim, why? Should change 7812 regulator on power board?
Or could it be nte ecg equivalents of replaced discretes above are actually not compatible regardless of blessed equivalency?
BTW, on powerdown, before solid green indication extinguishes, orange light very very short duration seen, is this bad news?
Ok five seconds boot permissivity blink green affirmative.
No , all tuner display segments non homogeneous illumination.
Particulars segments dimmer than others, rats, more investigation req'd.
Pushbuttons engage speaker pairs A or B triggers independent clicking sound relays, good news?
Advise tuner display dimness recovery please, it could be merely mini molex wiring reseating cure.
Regards, Curtis
No , all tuner display segments non homogeneous illumination.
Particulars segments dimmer than others, rats, more investigation req'd.
Pushbuttons engage speaker pairs A or B triggers independent clicking sound relays, good news?
Advise tuner display dimness recovery please, it could be merely mini molex wiring reseating cure.
Regards, Curtis
Client having difficulty amplifying tv thru sr4a out to kef spkrs so I explained sr4a will not accept digital but only analog from tv meaning client must find tv's left right analog audio outputs and route them into sr4a for amplification out into kefs.
Any advice? Maybe tv is digital output stereo audio which sr4a can not utilize as incoming signal??
Any advice? Maybe tv is digital output stereo audio which sr4a can not utilize as incoming signal??
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