Digital Pet repair

electronics that need repair. I had decided to task myself with learning w hat I need to know, but have reached a bit of an impasse and was wondering if I could get some help.

ctions fine, but I can't get two of the three buttons to work. I've disasse mbled and cleaned the contacts with alcohol and a q-tip, and coated the mem branes with CaiKote 44. The only result is that the one button that never g ave me issue now works like an absolute champ.

have both a cylinder and a ceramic capacitor, but neither look to be damag ed or leaking. Traces all look fine to me.

dentify what I need to fix?

ow why.

The best cure for a Virtual Pet is a real one. There are millions in need, and far too few takers.

Yes, they eat, require attention, take up space and all those 'inconvenient things' that living creatures do, but are well worth it.

Peter Wieck Melrose Park, PA

Plus no dodgy caps either although the occasional electrolyte emission may occur.

The dumb blonde sitting next to me says to check the rubber switch membrane to see if the carbon is worn off.

Oh, well, I have two real pets as well, but they are fully functional.

I'm trying to fix the electronic one that is not. :)

Rubber switch membrane? The only membranes I've got are the buttons in the front and the reset in the back. I've coated them in CaiKote, which is supp osed to help responsiveness, but hasn't helped this time. I guess I could t ry test a different set of button membranes? Couldn't hurt.

e front and the reset in the back. I've coated them in CaiKote, which is su pposed to help responsiveness, but hasn't helped this time. I guess I could try test a different set of button membranes? Couldn't hurt.

I haven't used CaiKote, but I use a carbon paint concoction that a part ven der mixed himself, and it works well if not spread on too thick.

Anyway, make a resistance check of the working rubber membrane and compare it to the ones that don't. Usually, with the probes a couple of mm apart, you should get a reading of at least 1K or less for reliable contact.

Also check the resistance of the painted-on circuit traces that often make up the circuit side of the "switch" to see if they're OK, again, comparing it the paths that work.

If everything checks out resistance wise, it's probably the chip (likely pr inted directly onto the PC and covered with a blob of expoxy).

Have you tried checking to see if the buttons work? It will be hard to do, but you can measure the resistance across the buttons when you press on them. Otherwise you would need to inspect the membranes.

BTW, how is "responsiveness" an electrical parameter? I don't even know what that is supposed to mean. Can you explain?