I have a box of childrens toys of the sound making kind. And among them is the "Vtech precomputer developer" I opened it, and to my surprise I can't find the meat of the machine. My guess is that its around the screen, because that's the only place that I have not checked. Anyone here done one of these? Here are two pictures taken of it. in the picture of it opened you will see a circuitboard. all there is behind it are contacts for the bottons in the first picture. any sugestions would be nice. I feel like I'm over my head. picture.
I've never bent this specific machine but i have come accross a few machines by grandstand / IQ builders where all the electronics are round the back of the screen and the rest of the case exists just to support the keypad. In fact once i had a wierd babies laptop thing where i couldn't find any electronics whatsoever, i can only assume that it was 'black blob' chips actually inside the screen assembly.
One thing to be careful of on a lot of Vtechs. They often have a low value resistor inside a piece of clear tubing on the board. This acts as a kind of fuse and will blow if you even look at it in a funny way. Just bridge it and the thing will leap back to life.
I opened it up the back and started to play with all the components, and the only part that does anything is a black chip that shorts it and you have to restart it every time. everything else is really small. Lets see...three black chips labeled as: LH5S4R40( it makes noise when you touch the connectors) 84CF33T, and 8018J. 4 capacitors, about 18 resistors. the "black blob" which I assume is what holds the information. I also see the "fuse" thing you were talking about. I have a basic knowlege of bending, and this thing has so many small circuits. So it proves to be most difficult. any cool tricks that I can utilize for this project?
in my experience 'black blob' circuits are rarely good for bending apart from the fact that they tend to have a clock speed resistor that can be replaced with a pitch pot, but not always. I suspect most of that circuit is the power supply and speaker amp.
V-tech's are wierd in that some have very high build quality and circuit design and can take a lot of punishment where as others look like they were built in a shed in someones garden in china. Some of the cheaper ones tend to be useless.
One thing to be careful of on a lot of Vtechs. They often have a low value resistor inside a piece of clear tubing on the board. This acts as a kind of fuse and will blow if you even look at it in a funny way. Just bridge it and the thing will leap back to life.
Yeah, this worked to bring my alpha desk back to life, good advice.
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fixed up one of my alpha desks... 