Hello Hello,
I have been tracking down an issue with my somewhat recently purchased (3 months ago) Rotel RCD-991. Welp, listening to it the other day and bam it just shut off. Checked the fuse and it was fine. Discovered a fusible resistor went out. Original part number ERD2FCJ4R7P. I couldn’t locate a direct replacement so purchased a couple that seemed close enough on DigiKey. The original was rated for 1/4 watt and would open if it saw 2.25 watts for 60 sec (per the internet, couldn’t find a datasheet). So the closest I could find was 1/3 and 1/2 watts of the same resistance so I grabbed a couple of each. None had that failure scenario. 1/3 watt didn’t publish info below 3 watts but might perform close.
Anyway, this circuit supplies the 5v+ to the CPU and tray. Tossed the 1/3 watt resistor in and everything came back to life. Measured about .25 watts across the resistor at idle and .5 watts with a disc playing. So I can see why the original 1/4 watt one eventually failed, but not seeing the 2.25 watts.
Sooo, to my question, anyone seen anything like this before and recommendations where to look next? I’m assuming the current has crept up or is it possible the original resistor ran beyond its rated capacity from the factory and finally gave up? Down stream voltage regulator holds at 4.99 volts with or without a cd spinning. Checked a couple adjacent capacitors and they were fine. Even if I find the culprit(s), still can’t find a resistor with the exact same parameters as the original. My plan is to probably go to the 1/2 watt resistor although it will only protect at about 12 watts. 1/3 watt resistor was getting pretty warm under load.
Thanks!!
I have been tracking down an issue with my somewhat recently purchased (3 months ago) Rotel RCD-991. Welp, listening to it the other day and bam it just shut off. Checked the fuse and it was fine. Discovered a fusible resistor went out. Original part number ERD2FCJ4R7P. I couldn’t locate a direct replacement so purchased a couple that seemed close enough on DigiKey. The original was rated for 1/4 watt and would open if it saw 2.25 watts for 60 sec (per the internet, couldn’t find a datasheet). So the closest I could find was 1/3 and 1/2 watts of the same resistance so I grabbed a couple of each. None had that failure scenario. 1/3 watt didn’t publish info below 3 watts but might perform close.
Anyway, this circuit supplies the 5v+ to the CPU and tray. Tossed the 1/3 watt resistor in and everything came back to life. Measured about .25 watts across the resistor at idle and .5 watts with a disc playing. So I can see why the original 1/4 watt one eventually failed, but not seeing the 2.25 watts.
Sooo, to my question, anyone seen anything like this before and recommendations where to look next? I’m assuming the current has crept up or is it possible the original resistor ran beyond its rated capacity from the factory and finally gave up? Down stream voltage regulator holds at 4.99 volts with or without a cd spinning. Checked a couple adjacent capacitors and they were fine. Even if I find the culprit(s), still can’t find a resistor with the exact same parameters as the original. My plan is to probably go to the 1/2 watt resistor although it will only protect at about 12 watts. 1/3 watt resistor was getting pretty warm under load.
Thanks!!