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Hi. I am putting together a Handyboard and have been having success until it
came time to test the bootstrap mode. The interface board's voltages check
out and it blinks as it attempts to download. I am using an E1 and the Mac
6811 downloader. The E pin emits 2.5 volts(I don't have a logic probe). When
putting it in bootstrap mode, both lights go out. When I attempt to download
something onto the board to test it, it gives me the message that it isn't
connected or in bootstrap mode. The serial light on the interface board
flickers. I measured the voltage at the RxD pin during the initial phase and
it flickers between 2.5 and 5 volts. However, the board's power light
doesn't light. The TxD pin voltage remains constant between 4 and 5. I
tested the continuity of the TxD from the MPU pin to the interface board and
it is 1K ohms( just the resistor pack). I opened up a serial communication
program(using a Mac and claris works). When typing letters, the serial light
flickers and RxD pin voltages changes. And SOMETIMES, when not in bootsrap
mode, the power light would rythmically blink and characters would appear on
my computer screen. I thought i just needed to install the memory, and
proceeded in putting in the memory power, latches and ram chip itself. The
memory power measures 5 volts. Now however, when I turn the board on
everytime the charge light rapidly flickers. When started in bootstrap mode
the charge light goes out, and ram voltage is at 5 volts. I can no longer
get the board in the mode where the power light pulses and sends characters
to the computer screen. After removing U7 and the U2( can't remove u3), the
charge light flickered much duller. The power light can now pulse and
transmit data. I seem to have two problems, the charge light and bootstrap
response
Thank you very much for any advice!
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