Help: My Replica 1 is also not resetting :(

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Help: My Replica 1 is also not resetting :(

Postby rdp837 » Jul Sat 14, 2007 9:23 pm


I'm having some trouble getting my Replica 1 up and running.

The Replica 1 passed the tests outline in "Testing your replica 1" on page 19 of the manual.
Computer displays a flashing @ sign. Pressing the reset button produces no effect.
Chip 6821 is hot to the touch (this may be normal I don't know).
Keyboard doesn't function.
Power is via USB (Jumpers 1,2 & 5 connected, the power light is always on no mater what position the switch is on).
Pin 37 of 6502 is at 2.3 V.
Upon pressing the reset button pin 40 drops from 4.9V to 0V.
Sync line on 6502 (pin 7) is 1.4V.
In the kit I was supplied with a chip labeled MCM60L64P10 QQQAC8913 I assumed this was a replacement for the 62256 as this was the only slot I had left over.
I have no luck using Hyper terminal to communicate with the Replica 1.
The oscillator is correctly aligned with the pointed corner facing MAX233.
I can't see any missed solder points and all the chips appear to be seated with no bent pins

Sorry I'm not really that skilled in electronics (I've only ever made one kit and I usually just solder cables together) and the only diagnostic tool I've got is my multimeter and I have no spare components to play with.

Thanks in advance,

Posts: 2
Joined: Jul Sat 14, 2007 8:34 pm

Postby rdp837 » Aug Sat 11, 2007 6:23 pm

I've replaced both the memory and the CPU but I still cannot input text via either the keyboard or the USB port.
Is the Replica 1 repair offer still valid?


Posts: 2
Joined: Jul Sat 14, 2007 8:34 pm

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