Got an Amiga 500 plus? Haven’t removed or replaced the motherboard battery yet? Well if you haven’t here’s the bad news; it’s got a good chance of having leaked on your motherboard. And if it has, and isn’t rectified that battery electrolyte could well eat away at the tracks on the PCB eventually rendering it useless.
The good news is that if it hasn’t got too bad in there, you can easily remove the battery and clean up your board. This how-to only applies to Amiga 500 plus models and not the Amiga 500 which can have a battery on a memory expansion board in the trap door (you still might want to replace/remove it mind you!).
This short tutorial only covers the removal of the battery, either by breaking away or desoldering. It does not cover the replacement of the original battery with a modern ‘coin battery’ and holder which can be purchased from the Amiga Kit store. I personally have never found a need to have a clock battery on my A500+ motherboard, therefore removal is all I cover here.
Disclaimer: I take no responsibility for any damage you do to yourself or your A500+ during this process. You proceed at your own (and your Amiga’s) risk!
What you will need:
A ‘Torx’ T10 driver
Long nose pliers
Soldering iron and desoldering braid (if you want to desolder)
Step 1: Dissassembly
Turn your Amiga over and remove the six T10 screws in the positions marked on Pic A. Once removed turn your Amiga back over again and lift off the top casing. Put that on one side.
Pic B – The warranty seal was still intact on this A500+ which is how I knew the battery would definitely need replacing. A nervous time ahead as we find out what damage has been done!
The keyboard is pretty much loose as soon as the top casing is removed. The keyboard is only connected by a cable that goes through a hole in the shielding and can be removed by gently pulling and wiggling the cable until it comes free (Pic C). Remove the keyboard and put to one side (Pic D).
To remove the shielding you must first bend 4 tabs up and remove 4 T10 screws marked in purple and green respectively on Pic E.
Once done the shielding will lift off but be aware of the 2nd small piece of shielding by the expansion edge connector on the left hand side which will now be loose too. Put the pieces of shielding to one side.
Step 2: Battery removal
You will now be able to see the battery and what damage (if any) it has done to your motherboard (Pic F). In this instance I was lucky and once I had removed all the fluff (with a photographers blower brush and vacuum cleaner) I could see the leakage had started but was confined to the sides of the battery only. A huge sigh of relief then! The battery had corroded to the terminals however so was probably going to involve removing those too. This was my intention anyway as I personally have no use for a battery in this A500+.
At this stage, you can opt to be civilised and desolder the terminals from the motherboard or just be brutal (it’s not that bad really!) and just pull the terminals away from the board by gently rocking the battery back and forth as in the pics above until the solder points break. Be careful not to grip the battery too tightly here or you will hasten the escape of electrolyte onto your motherboard and after all this whole excercise is meant to prevent that happening.
Be aware that these batteries contain Cadmium which is pretty nasty stuff if ingested. So wash your hands thoroughly after handling removed batteries. Also make sure you dispose of them correctly, these should be safely recycled not thrown out with the rest of the rubbish!
If your motherboard has been leaked on you can clean it up with some diluted lemon juice or vinegar on a sponge. This will also neutralise the alkaline from the battery preventing further damage occurring.
And before reassembling your Amiga take a little time to clean the inside of your computer and keyboard with a small brush and vacuum cleaner, there will undoubtedly be decades worth of fluff, dead skin cells and bits of biscuit hanging about in there.
Step 3: Reassembly
Assembly is the reverse of the above steps but take care to replace the small shielding around the left hand edge connector (Pic G) before replacing the main shielding as 2 of the T10 screws have to go through both shields (Pic H). This can be a bit fiddly!
If the damage wasn’t too great you should now have a working Amiga without that ticking timebomb of a battery onboard. Time for some games…