Re: Nakamichi Soundspace 3 no FM radio, bad diode?

Is there any way to perform an equivalent of this test without a scope-the only tool I have at the moment is DMM

Re: Nakamichi Soundspace 3 no FM radio, bad diode?

Hmm... where do I go next? I checked the film capacitors and I found one circled that was supposed to read 220 nF but measured ~193 nF. The others were ~1 nF around their expected values. There is no letter code on it-indicating tolerance as I understand it…...

Re: Nakamichi Soundspace 3 no FM radio, bad diode?



I'm assuming that's between pins 9 and 5 (GND)- never tested an IC before: it's 5 volts... which looks like it's within spec. So a bad IC then?...

Re: Nakamichi Soundspace 3 no FM radio, bad diode?

Sorry I thought that mirroring would make it easier to id the top components on the bottom of the board. Anyway, voltages from the L & R output of the IC (pins 13 and 14): 48mV (supposed to be 1.8V according to the data sheet) and have a resistance of 6.64 k ohms (supposed to be 3.3 k ohms according to the data sheet).

Re: Nakamichi Soundspace 3 no FM radio, bad diode?

There are three units: the main, companion, and subwoofer. Behavior isn't altered with/out the subwoofer attached-so not pictured. Order of attached pictures are main top; main bottom; companion top; companion bottom (all pictures are maximum size 1333x2000 (click to enlarge)

As an interesting aside, the capacitor change didn't do anything to fix the radio-but it does now retain the time if the power is lost (previously would have to reset clock after power failure) and it doesn't make crackling sounds when the volume...

Re: Nakamichi Soundspace 3 no FM radio, bad diode?



Thanks for the reply, I haven't pulled yet but am planning to soon. It appears that it's wired in series with the other one and there are no connections between them so I am assuming there should be only current flowing one way like the other one. Unfortunately, I don't have the datasheet so I don't have a part number. If it's bad there's really no easy way to figure out the voltage and I'll have to the do it the hard way with a power supply, resistor, and multimeter, correct?...

I bought a Soundspace 3 new back in 2003 and it's faithfully woken me up until recently because it's lost the ability to receive FM radio stations (AM, CD, AUX works fine).
When switched to FM, you can hear static normally but as soon as I hit a stereo broadcast the volume goes dead and I have to turn it up to max to barely hear the broadcast. I have basic diagnostic troubleshooting experience but I'm perplexed about diodes. I've found a bad diode (circled) It's wired in series, not parallel, with D109. D109 works like it should. D110 it lets current through both ways. Does anyone know...

Re: New Members - please post your introductions here

Very helpful forum, interested in learning about electronics repair and being able to contribute!