Oliver Stephen Hannaford-Day:

Thats a NiCad battery. PCB mounted batteries have a tendancy to do that if left alone for 15 years sadly.

The battery acid eats the tracks around the battery and worse, the copper out of the via's. The crystal case was destroyed too.

The crystal has now been replaced and any open circuit tracks have been remade but I think theres damage under some of the chips so will need to desolder the chips (and probably socket them) to check.

Fun times. :-)

I had a television set which one day lost all its channel tuning information. I was able to restore the information but it lost it all again the next time it was switched off. I had a look in the back and found indeed a similar NiCad cell looking in a sorry state, though there was 1·2 V across it with the set switched on. Fortunately the tracks were still in reasonable condition. I could not source an identical cell for replacement, so I just procured what I could - the wrong size so I hitched it to the board with flexible wires. It looked a mess but at least the set retained its tuning again. It lasted several more years, then one day the picture disappeared and it emitted lots of smoke. I decided it was time to send it to WEEE recycling.


COULD I DO SOMETHING LIKE THIS NOWADAYS?


It is getting more difficult. For instance I still have a video tape recorder, used on odd occasions, sometimes for copying video cassette to DVD. It retains the tuning channels OK but if it looses mains power the internal clock stops. Without a service manual I have been unable to identify a cell that would maintain the internal clock under loss of  power. I once replaced a similar cell on a laptop computer a few years ago when I was still working. These cells are very small and difficult to distinguish from other components.

Oliver Stephen Hannaford-Day:

Thats a NiCad battery. PCB mounted batteries have a tendancy to do that if left alone for 15 years sadly.

The battery acid eats the tracks around the battery and worse, the copper out of the via's. The crystal case was destroyed too.

The crystal has now been replaced and any open circuit tracks have been remade but I think theres damage under some of the chips so will need to desolder the chips (and probably socket them) to check.

Fun times. :-)

I had a television set which one day lost all its channel tuning information. I was able to restore the information but it lost it all again the next time it was switched off. I had a look in the back and found indeed a similar NiCad cell looking in a sorry state, though there was 1·2 V across it with the set switched on. Fortunately the tracks were still in reasonable condition. I could not source an identical cell for replacement, so I just procured what I could - the wrong size so I hitched it to the board with flexible wires. It looked a mess but at least the set retained its tuning again. It lasted several more years, then one day the picture disappeared and it emitted lots of smoke. I decided it was time to send it to WEEE recycling.


COULD I DO SOMETHING LIKE THIS NOWADAYS?


It is getting more difficult. For instance I still have a video tape recorder, used on odd occasions, sometimes for copying video cassette to DVD. It retains the tuning channels OK but if it looses mains power the internal clock stops. Without a service manual I have been unable to identify a cell that would maintain the internal clock under loss of  power. I once replaced a similar cell on a laptop computer a few years ago when I was still working. These cells are very small and difficult to distinguish from other components.