I recently bought a set that included the small 9v battery box (the one that contains a single battery) and it has 2 potential problems:

1.The switch is a little sticky (i.e. it doesn't always pop back up when you turn it off)

and 2.The interior of the box is covered in something that looks a little like corrosion or something (not just the metal bits, the plastic bits too)

The box works just fine however.

My question is, should I bother removing the gunk inside the battery box and if so, how? And, is there anything I can do to make the switch less sticky without risking damage to the box?

I recently bought a set that included the small 9v battery box (the one that contains a single battery) and it has 2 potential problems:

1.The switch is a little sticky (i.e. it doesn't always pop back up when you turn it off)

and 2.The interior of the box is covered in something that looks a little like corrosion or something (not just the metal bits, the plastic bits too)

The box works just fine however.

My question is, should I bother removing the gunk inside the battery box and if so, how? And, is there anything I can do to make the switch less sticky without risking damage to the box?

I'd advise asking Lego for a replacement. When thinks get gunky like that they don't often want to work later.

if it works fine you should keep it and clean it.

The gunky stuff might be leaked battery acid. Should not be that hard to remove with a solvent.

Unfortunatly, the part in question (which was purchased used as part of a nearly complete 5391 SP-Striker) has not been used since 1998 or so and it is unlikely that TLG still has any around.

The part in question is this one

http://www.bricklink.com/catalogItemIn.asp...rID=11&in=S

Given that the lot was sold as-is, its not the end of the world if it stops working down the track, I just want to see if there is anything I can do about the problems.

Yes, you won't get a replacement for that now. Have you tried to see if it works? I once had leaked acid on a control center's battery contacts, but it came off pretty easily with alcohol. The unit has continued to work fine since then.

As for the switch, you may just be seeing its normal behavior. If you push it down at a certain angle, it's supposed to stay down, and it pops back up if you pull it outwards.

And if nothing works (although I cannot imagine - as CP already pointed out, alcohol should do the job), it´s no big deal to get them at Bricklink.

Black and white are sold for around 1$+, yellow from 3$ on, red is the most expensive with 7$+.

Unfortunatly, the part in question (which was purchased used as part of a nearly complete 5391 SP-Striker) has not been used since 1998 or so and it is unlikely that TLG still has any around.

The part in question is this one

http://www.bricklink.com/catalogItemIn.asp...rID=11&in=S

Given that the lot was sold as-is, its not the end of the world if it stops working down the track, I just want to see if there is anything I can do about the problems.

I'm selling one of them on eBay

Check the link in my sig!