I have a Linn Majik DS with Dynamic PSU which was suddenly dead last Sunday. It produced only a low volume sparking noise when repowering but the display remained dark.
I found on the Internet that a cap in the power supply causes this error, see here.
I opened my unit but unfortunately, I have a different PSU as seen below.
It has two of these suspicious caps but no obviously faulty element on the PCB.
Anyone out here knowing this problem and what component to replace?
I found on the Internet that a cap in the power supply causes this error, see here.
I opened my unit but unfortunately, I have a different PSU as seen below.
It has two of these suspicious caps but no obviously faulty element on the PCB.
Anyone out here knowing this problem and what component to replace?
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Do you know power supply out cable colours voltages? Check output voltages, if you don't know, check out put capacitors voltages.
Be careful, primary power supply has high voltage capacitors and is conected to mains.
Be careful, primary power supply has high voltage capacitors and is conected to mains.
After having the device disassembled for making the pictures posted the unit started as normal.
After a while (some days to weeks) it was dead again.
I disconnected from mains, waited a day or two and switched it on again - it is running as normal.
Guess it will be difficult to track down the fault. Any ideas?
After a while (some days to weeks) it was dead again.
I disconnected from mains, waited a day or two and switched it on again - it is running as normal.
Guess it will be difficult to track down the fault. Any ideas?
test/replace all electrolytics. Be sure to safely discharge the hot side first - a high wattage 5 or 10 ohm resistor much more comfortable than your hand 🙂
And the same 22/50 one near the connector + the 5 Nichicon caps. Let the PSU bleed a few minutes after switch off. Measure to be sure it is safe to handle. Replace caps and inspect and resolder cold solder joints with 60/40.
Switchers....never a dull moment.
Switchers....never a dull moment.
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I see you posted an additional pic of the area near D4. It looks like the power MOSFET has been ...worked on...? As the rest of the board was wave soldered and cleaned the goopy flux in that area is suspicious. I'd reflow the solder on that leg since you're already inside the unit.
Yes, it looks like both visible legs of the MOSFET have dry joints, one worse than the other, and a reflow with fresh solder is a good starting point.
Thanks so far. I had little time over the summer and startet to track down the fault recently. As explained the unit is working fine after having been disconnected from mains for a while in working state, the output voltages are from right (1, black) to left (10, dark grey):
1: -11,2
2: 0
3: 0
4: -0,02
5: +6,38
6: +6,38
7: +0,06
8: -16,72
9: 0
10: +15,09
after some days on mains, the unit is dead. Voltages are
1: +9,88
2: 0
3: 0
4: 0
5: -0,02
6: -0,02
7: -0,01
8: +0,18
9: 0
10: -0,11
All voltages are measured against 0V close to pin 1 (black) of the connector. Hope this helps.
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Yes, after having again a more thorough look onto the board, I noticed some debris close to D4, i.e. at the pins of the TOP246. It looks like a hard, transparent coating about 0,2 - 0,3 mm thick. On the bottom side is some debris as well, again at the pins of the TOP246.
I got this unit pre-owned 8 years ago and do not know about earlier repairs.
If there are no better ideas, I will start replacing the 22/50 (C37/C27) + the 5 Nichicon caps and reflow the pins of the TOP246 with fresh solder.
I finally found some time to replace all electrolytics and to reflow the pins of the TOP246 with fresh solder.
The outcome is disappointing:
The unit plays nicely when plugged to mains. On the next morning, the unit is dead. I pluged in after 24 h, but it remains dead. It has to be disconnected for about 48 h to recover. Thus, nothing has changed.
I can replace the TOP246 (I ordered three together with the caps). What's the opinion of the pros: Might this be helpful? Any other ideas?
The outcome is disappointing:
The unit plays nicely when plugged to mains. On the next morning, the unit is dead. I pluged in after 24 h, but it remains dead. It has to be disconnected for about 48 h to recover. Thus, nothing has changed.
I can replace the TOP246 (I ordered three together with the caps). What's the opinion of the pros: Might this be helpful? Any other ideas?
Hopefully my last update to this thread:
I replaced the TOP246YN with a new one 10 days ago and the unit is up and running again since then.
I replaced the TOP246YN with a new one 10 days ago and the unit is up and running again since then.