Micro Genius IQ-1000 Technical Issues

Started by umjammercammy, May 07, 2019, 08:33:00 am

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umjammercammy

I have a Micro Genius IQ-1000 that's got a couple odd problems.

For starters, the power button doesn't work at all. The system turns on immediately the instant it's plugged in.

The second problem is that the audio is very crunchy and distorted. I just got done recapping the system but it had no effect on the audio at all. 
Would anyone have any idea what the problem is?

FAMICOM_87


umjammercammy

It's discrete, it had UMC chips inside originally. I swapped the UMC CPU for a legit Nintendo CPU but this has had no effect on the sound other than correcting the typical swapped cycles. The crunchy distortion is still there.

FAMICOM_87

did you try to get sound directly from pin 46 on the cartage slot  :question:

krzy

Quote
For starters, the power button doesn't work at all. The system turns on immediately the instant it's plugged in.

Button might be internally shorted (broken). You can try to fix it by disassembling everything and maybe bending a little the small metal element inside but those buttons (I call them isostats) need a litle patience when fixing, you can easily lose the spring for example or it can shoot into your eye:
https://www.google.com/search?q=isostat&source=lnms&tbm=isch&sa=X

Quote
The second problem is that the audio is very crunchy and distorted. I just got done recapping the system but it had no effect on the audio at all.
Would anyone have any idea what the problem is?

Probably some resistor in the audio-mixing circuint have incorect values. For example, the ones from CPU PIN1 and PIN2 into GND should be 100R, no more.

krzy

Few days ago I made a complete reverse-engineering of IQ-1000 and IQ-2000 - I recommend you reading schematic for those consoles here:
http://forums.nesdev.com/viewtopic.php?f=9&t=18984

The values of channel mixing resistor in audio path (R21, R20) should be 20k and 12k, not 390 and 240.
If console does not react on power-up then probably 4013 chip need to be replaced).

boye

Quote from: FAMICOM_87 on May 08, 2019, 12:55:06 am
did you try to get sound directly from pin 46 on the cartage slot  :question:

Pin 46 is an audio input, not an output.
Can't find the FDSLoadr PC program? Get it here. It took me way too long to find.

P

Nope pin 46 is final audio output. Pin 45 is input to the cartridge and amplified output from the APU.

Cartridge pinout