Looking for an experts help here.
I found the Marantz SR-2000 receiver locally with blown fuse. Typical reason would be shorted output STK modules - checked them and indeed one was shorted. Replaced both STKs with STK082G (instead of original STK080G) and the unit worked fine for few days.
Recently it started to blow fuses again; immediately on power on. Checked STKs - no shorts, both measure good. Looking further, I found shorted Q806 diode in the power supply circuit (0 Ohms both ways, even when removed from the board). Also collector of Q807 was measuring short to ground. This could have been a shorted Q806 along with low resistance of the transformer coil, but I still put an isolation pad under the Q807 (the collector is connected to the flange and to the grounded heatsink). I also replaced shorted diode.
After these fixes the unit powered up and even got normal sound from both channels.
However after few minutes I felt a burning smell and then fuse blew again. I replaced the fuse and the thing repeated - everything was normal for a few minutes then burning smell and blown fuse. The volume is on the low level and the speakers are 8 Ohm so it is not overload.
The main power transformer is heating up and even smokes a little bit. I am sure the burning smell goes from the transformer. I cleaned the old thermal paste and generously applied new one - that did not help. Light bulb test also fails - the bulb is bright which is not normal. I even unsoldered all power transformer secondary circuits from the board to eliminate any secondary load on the transformer - it still fails light bulb test (bright bulb) and heats up.
I measured AC current from the secondary coils to the board. Nothing too bad here (about 300 mA for power amp circuit at connection points J816 and J817, about 300 mA at the point J820 (power source for everything but power amps) and just a few mA at the J822 (lights).
All this points to the power transformer failure. Probably partially shorted coils? I understand power transformers rarely fail but this is still possible.
I checked eBay for the user parts and only can find a single transformer for SR-2000 unit. However that transformer is from Canadian unit. The part number is TS17514020 (and US part number is TS17614010). As far as I understand, Canada and USA have the same AC power standard - 120V/60Hz. Would the Canadian transformer work in USA unit? Theoretically it should, but I am confused by different part numbers.
Can anyone suggest other online places beside eBay I can look for the transformer? Of course, I checked local Craigslist and Facebook already.
Thank you!
I found the Marantz SR-2000 receiver locally with blown fuse. Typical reason would be shorted output STK modules - checked them and indeed one was shorted. Replaced both STKs with STK082G (instead of original STK080G) and the unit worked fine for few days.
Recently it started to blow fuses again; immediately on power on. Checked STKs - no shorts, both measure good. Looking further, I found shorted Q806 diode in the power supply circuit (0 Ohms both ways, even when removed from the board). Also collector of Q807 was measuring short to ground. This could have been a shorted Q806 along with low resistance of the transformer coil, but I still put an isolation pad under the Q807 (the collector is connected to the flange and to the grounded heatsink). I also replaced shorted diode.
After these fixes the unit powered up and even got normal sound from both channels.
However after few minutes I felt a burning smell and then fuse blew again. I replaced the fuse and the thing repeated - everything was normal for a few minutes then burning smell and blown fuse. The volume is on the low level and the speakers are 8 Ohm so it is not overload.
The main power transformer is heating up and even smokes a little bit. I am sure the burning smell goes from the transformer. I cleaned the old thermal paste and generously applied new one - that did not help. Light bulb test also fails - the bulb is bright which is not normal. I even unsoldered all power transformer secondary circuits from the board to eliminate any secondary load on the transformer - it still fails light bulb test (bright bulb) and heats up.
I measured AC current from the secondary coils to the board. Nothing too bad here (about 300 mA for power amp circuit at connection points J816 and J817, about 300 mA at the point J820 (power source for everything but power amps) and just a few mA at the J822 (lights).
All this points to the power transformer failure. Probably partially shorted coils? I understand power transformers rarely fail but this is still possible.
I checked eBay for the user parts and only can find a single transformer for SR-2000 unit. However that transformer is from Canadian unit. The part number is TS17514020 (and US part number is TS17614010). As far as I understand, Canada and USA have the same AC power standard - 120V/60Hz. Would the Canadian transformer work in USA unit? Theoretically it should, but I am confused by different part numbers.
Can anyone suggest other online places beside eBay I can look for the transformer? Of course, I checked local Craigslist and Facebook already.
Thank you!
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