Heineken
16-07-2023, 05:33 PM
While working on the radio from France anther one via NSX prime from the USA came in. All inputs and functions were fine but the speaker output was intermittent and worked only for a few seconds before cutting in and out randomly. Since there was obvious damage by leaking capacitors, their replacement and taking care of the PCB was the first item on the list.
14824
traces near E509
With the large capacitors removed, it became more obvious.
14825
no massive damage but on a good way to cause further problems.
In addition, the flex cable connector next to the CD port showed suspicious greenish marks, usually related to being contaminated, too.
14826
that colour ain't supposed to be there
After removal of the flex cable it became rather obvious why there was intermittent sound. The pins were corroded up to a level where they potentially lost contact completely. This requires a new connector and a new cable before continuing any further. After removal of the connector, some pins measured a resistance of less than 200 kΩ against other pins - in an OK connector they should be >2 MΩ.
14827
not looking good
Since the whole area was contaminated, it required the usual treatment: Cleaning the PCB down to bare metal and strengthening the VIAs by soldering a thin wire through them - about 30 of them were reworked like that, including the capacitor area.
14828
that should be better
A first test run and and one cold solder point later the radio was working stable and the two remaining capacitors on the power PCB were replaced. Not much damage to traces there but the capacitors already started leaking, too.
14829
on the bench
The US PCB layout seems to be more robust against acid damage. The usual path of the capacitor liquid does not cross too many components and as there is no extra processor one the lower PCB, required for the RDS decoding on EU radios, that one can't be damaged either. Happy to have a more-or-less regular repair instead of the usual, more difficult cases.
14824
traces near E509
With the large capacitors removed, it became more obvious.
14825
no massive damage but on a good way to cause further problems.
In addition, the flex cable connector next to the CD port showed suspicious greenish marks, usually related to being contaminated, too.
14826
that colour ain't supposed to be there
After removal of the flex cable it became rather obvious why there was intermittent sound. The pins were corroded up to a level where they potentially lost contact completely. This requires a new connector and a new cable before continuing any further. After removal of the connector, some pins measured a resistance of less than 200 kΩ against other pins - in an OK connector they should be >2 MΩ.
14827
not looking good
Since the whole area was contaminated, it required the usual treatment: Cleaning the PCB down to bare metal and strengthening the VIAs by soldering a thin wire through them - about 30 of them were reworked like that, including the capacitor area.
14828
that should be better
A first test run and and one cold solder point later the radio was working stable and the two remaining capacitors on the power PCB were replaced. Not much damage to traces there but the capacitors already started leaking, too.
14829
on the bench
The US PCB layout seems to be more robust against acid damage. The usual path of the capacitor liquid does not cross too many components and as there is no extra processor one the lower PCB, required for the RDS decoding on EU radios, that one can't be damaged either. Happy to have a more-or-less regular repair instead of the usual, more difficult cases.