Corroded contacts

Some guidance would be most welcome.......

My Pentax AF080C ring flash unit's battery contacts have become corroded with a blue crust (copper Sulphate?( making the unusable.

Would it be possible/ advisable for me, without either damaging the unit or electrocuting myself, to remove the contacts from the flash body & clean them?
There are four screws in the bottom of the battery compartment that look as though they would allow the separation of the body to access the contacts.

Any thoughts/ guidance would be most welcome.

Thanks,

Roger.

Unfortunately, as I've discovered, the corrosion can run along the contacts to the circuit board and then, I'm afraid, it is normally game over.

That said, I use a fibreglass pen (designed for the purpose) to clean contacts. Worth a try. It'll reach the contacts without dismantling.

This sort of thing> http://www.ebay.co.uk/itm/HAMA-GLASS-FIBRE-ELECTRICAL-CONTACT-CLEANING-PEN-BATTE...

Can't remember where I bought mine - probably off the Bay; came with a number of 'refills'.

Also, again can't remember, there's a common household product that dissolves and neutralises battery corrosion. Anyone?

Good morning. You should be able to open unit by removing those 4 screw and clean it with baking soda/ vinegar/ electrical contact cleaner (Halfords have them for £4) or/and with emery paper some fine grade then you need to check interior for damage if there's anything, you can try to use soldering iron to solder again. Hope this helps, but have in mind, I wrote this as I would do this so be careful and wear protection gloves/glasses...

Or in here is an article "how to" worth to read:link

Thanks for the above, chaps.
I'll attempt a repair at the weekend, when the mini screwdriver set arrives.....

Keep every thing crossed!

Roger.

I look forward to your repair - I have the same flash that when it arrived had some corrosion, I manage to carefully scrape away as much as possible and it now seems to work consistently, but a more thorough clean might be worthwhile at some point.

If you happen to take a few photos of the process it could turn out to be on of those really useful topics that could be long used as a reference

Will do, LennyBloke.

Roger.

Well, job done then!

Undid the four screws (mini-Philips), lifted them out with the magnetic pick-up tool that came with the set.
This allows the separation of the unit body, the battery compartment lifting away easily.
It's further movement away is limited by the wires (soldered) to each of the four negative battery terminals/spring contacts, where the corrosion sits.
The cable length just allows the rear of the clips to be accessed. They are each held to their common back-plate by two small tabs, bent over to secure.
On bending the tabs open, each can be inspected & worked on to clean them up.
Anyone adept at soldering could, I'm sure, de-solder each of the clips, which would increase the accessibility for the cleaning operation.
I found, quite late in the operation, that the plastic plate that holds the four battery contacts (by the two bent tabs) can in fact be removed by bending it back away from the battery "tray", it being held by a simple plastic clip at the top.
I found the task quite simple, if a little fiddly! Three hands at some stages could be useful!

I would not discourage anyone from undertaking the job.

NOTE.
I avoided touching any of the other components, wires, etc., lest any of the horror stories of lots of volts should strike me down in my prime!!

The unit is now functioning correctly & has reclaimed its position as my go-to lighting source for macro.

If your contacts are feeling blue, have a go!


Roger.

A couple of snaps to follow. I found it difficult enough to see, let alone image the components &their location in situ.
If there are any questions, let me know.

The problem:





Remove the batteries & you'll see four of these. Remove them.





Separate the unit by lifting the battery compartment. Avoid touching any of this!





Showing the corroded tabs to each of the four negative battery clip/contacts




Two of the bad tabs bent back to release the clip. Not all were corroded.




Add vinegar to taste!

Roger.

Well done on a good job.
As you said though, DO NOT touch other components, particularly capacitors as they can hold very high voltages even in small flash units, I know from experience