Preamble
A terribly badly made toy cheetah with LED eyes, and two motors to make the cheetah bound.
PCB component layout
The PCB has many issues. The PCB silkscreen legend doesn’t match the components – it is as if the PCB has been repurposed – thus, many components are either missing or replaced with different types of components – for example, where a transistor should be, an electrolytic is used instead (!!?!!). Also, some components on the PCB haven’t been labeled in the legend – these have been labelled as R98, R99 and C99. In addition, two component legs have been put in one through-hole, at least two examples of this:
- R99 and Q4(3)
- R98 and R4
- R5 and Q5(3)
The main repair issue is that some wires were broken and it is not clear where they should go:
- Motor positive
- positive supply
- possibly the ground
The PCB track and through hole alignment also leaves much to be desired – which makes reverse engineering it a bit of a headache. It is arranged on a rough 11 wide by 9 high grid.
The top of the PCB is actually the bottom in the photo of the tracks, above. The IC is hidden under the black blob of resin.
Wire colours are:
- Yellow – motor1 positive
- White – motor1 negative
- Black – ground (this connection is not definitely correct
- Red – positive supply 6V
- White and white – LED
- Red – motor2 positive
- White – motor2 negative
- Blue and blue – loudspeaker (top two connections on the left, direct to IC)
gr33nonline 