So while cleaning up my grandparents house we found one of these beautiful 1986-babies lying hidden deeply in one of our cupboards. We couldn't overcome our curiosity, so I grabbed two AAs, put them in... and nothing happened. I tried again and again, replacing the batteries three times even with brand new ones from the store. Still nothing. Then I decided to give up, left the batteries inside and started playing around with the buttons - and it suddenly worked! I was amazed of course, so I stopped it, went on to show my grandparents, pressed the button... and nothing happened. I checked the main board and battery compartment afterwards but couldn't see any blown capacitors or broken solder joints. It just turns into a brick, no movement, no sound, no battery light, nothing. So I wonder what may be wrong with it. I guess if I try it often enough it will work again for some time, but maybe there is an easier solution. The unit is pretty dusty, but I don't think that's the problem because also the radio doesn't work if the unit is dead, which doesn't need any buttons to activate except the switch on the top which works. I tried Fujitsu, Duracell and Energizer-Batteries, all worked until the unit died again. I guess something is wrong with the connection between the batteries and the circuitry. I can post pictures of the main board and stuff if you need them, of course. Cheers!
Have you checked the battery springs and plate? A layer or rust or oxidisation and a bad contact patch is often the case. They may need a little clean or for more serious tarnishing a proper clean/refurb
As far as I can tell, they are as clean as they can be. Some scratches are on there, but that shouldn't be a problem, or? Btw, it doesn't have springs, but little metal plates that were bent into a kind of V-shape. Could these be the problem?
Ok if the springs or plates are looking clean then you may wish to look at the solder around the battery area and look for any bad solder joints and touch them up if required. Last thing will be caps to check to see if any need relacement but this might require you sending to a pro I can recommend @Sergi for any repairs.
Alright, so I just noticed something in a... lets say... brutal way. I checked the solder once more and put it back together, still nothing. Then I dropped it by accident. Nothing broke, but it suddenly worked! Then it died again, so I hit it a little with my hand... and it works again! So there has to be a connection problem that can be solved by force. I think it has something to do with the plates because their connection with the batteries looks pretty weird.
Ok so its definitely a power related issue and the trauma connects a circuit again. Re touch the solder joints from batteries to board and im betting that will solve it. Its probably a cold solder joint.
