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Martaine2005
- May 12, 2015
- 4,949
- Joined
- May 12, 2015
- Messages
- 4,949
Hello,
That was rather unfortunate. If you are very lucky, it could be just the fuse.
In your first picture by the two black wires, there is a small black circular device. That looks like the pcb fuse. You can check that with simple continuity.
I would clean the board as well, because water marks can look like component damage too.
Martin
That was rather unfortunate. If you are very lucky, it could be just the fuse.
In your first picture by the two black wires, there is a small black circular device. That looks like the pcb fuse. You can check that with simple continuity.
I would clean the board as well, because water marks can look like component damage too.
Martin
Martaine2005
- May 12, 2015
- 4,949
- Joined
- May 12, 2015
- Messages
- 4,949
Isopropyl is a good all round cleaner. But any pcb cleaner should remove water marks.
That is why I suggested cleaning the board. Because those marks may or may not be damage.
If it's a little damaged track, it can be repaired by bridging another wire to the next component.
But one step at a time. Clean the board and check the fuse..
Martin
That is why I suggested cleaning the board. Because those marks may or may not be damage.
If it's a little damaged track, it can be repaired by bridging another wire to the next component.
But one step at a time. Clean the board and check the fuse..
Martin
73's de Edd
- Aug 21, 2015
- 3,622
- Joined
- Aug 21, 2015
- Messages
- 3,622
.
Sir danray . . . . .
As grungy as that board looks I would also use "409" and a stiff bristled toothbrush and hold the PCB proper vertical so that you can
work sequentially with all four sides and that technique will also let the wet contamination drain down quickly off the boards main components.
Follow up with a clean rinse, and a cleaning redo if not fully satisfied.
I then dry the board quickly with a leaf blower.
Without my doing a markup, if the area you mention is burnt open that is the main B+ buss of the power supply as it originates from the
+ terminal of the BD1 full wave bridge rectifier mounted at the end of the alum-i-ninny yum-yum heat sink.
The fuse should be blown and if you follow the AC cord termination lands there is a slot cut in the board for isolation and the BLACK fuse bridges
across that gap at one end.
I suspect failure analysis to reveal that the "grunge" still retained such an amount of moisture, such that 160 volts of B+ creeped across and conducted to
sensitive areas. . . . . . . then unit then go BOOOOOOOOM !
Particularly the units High Voltage FET that is mounted at the broad side of the heat sink, you may find it dead shorted as well as sections of the BD1.
Feed back to us the number on the power FET ( HAK306 ? ) as well as the working voltage on the BLACK, big main filter capacitor that is nestled within the corner
of the heat sink across from the WHITE main switchmode power transformer.
Also the numbering on the small central IC ( UC38xx family ? ) that is the brains of this units SMPS.
Thasssit for now . . . . .
73's de Edd
.
Sir danray . . . . .
As grungy as that board looks I would also use "409" and a stiff bristled toothbrush and hold the PCB proper vertical so that you can
work sequentially with all four sides and that technique will also let the wet contamination drain down quickly off the boards main components.
Follow up with a clean rinse, and a cleaning redo if not fully satisfied.
I then dry the board quickly with a leaf blower.
Without my doing a markup, if the area you mention is burnt open that is the main B+ buss of the power supply as it originates from the
+ terminal of the BD1 full wave bridge rectifier mounted at the end of the alum-i-ninny yum-yum heat sink.
The fuse should be blown and if you follow the AC cord termination lands there is a slot cut in the board for isolation and the BLACK fuse bridges
across that gap at one end.
I suspect failure analysis to reveal that the "grunge" still retained such an amount of moisture, such that 160 volts of B+ creeped across and conducted to
sensitive areas. . . . . . . then unit then go BOOOOOOOOM !
Particularly the units High Voltage FET that is mounted at the broad side of the heat sink, you may find it dead shorted as well as sections of the BD1.
Feed back to us the number on the power FET ( HAK306 ? ) as well as the working voltage on the BLACK, big main filter capacitor that is nestled within the corner
of the heat sink across from the WHITE main switchmode power transformer.
Also the numbering on the small central IC ( UC38xx family ? ) that is the brains of this units SMPS.
Thasssit for now . . . . .
73's de Edd
.
