Re: Help with MC68HC908AZ60 2J74Y chip please.

tel1e@xxxxxxxxxxx wrote:

On 20 Dec, 01:16, SloppyChoppy (Chun...@xxxxxxxxxxxxxx) wrote:


Before risking the chip to an unsure reading process, I would check
that the reset circuit is not sending multiple pulses to the chip.
The reset is responsible for setting the digital stuff to the
same sync point and initialize the startup values... If it's sending
multiple pulses, it can cause similar problems. Sometimes the reset
is simply a single small chip or Transistor-resistor-Capacitor-cmos gate
arrangement. A good logic probe or O-scope should help.

Cars power systems are very harsh... so there would mostlikely be a voltage
regulator for that chip somewhere near it. I would check that those parts
haven't degraded.. Flakey regulator, clamping diodes, capacitors can cause noise
on the PS lines. A Fast needle meter or O-scope should help here.

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Hi,
Thanks for your help....here's a few pictures of the circuit
board...can you see / direct me to any of the components you mention.

http://i130.photobucket.com/albums/p256/on1wheel_2006/Picture001.jpg

http://i130.photobucket.com/albums/p256/on1wheel_2006/Picture007.jpg


Regards.
Get out your magnifying glass and look for cracked solder joints. Then,
with component coolant spray, after the board has heated up to the working stage. Spray little area's to seek a failure spot..

Beyond that with your apparent skill set, I think you should pass it
on to some one else if you really want that board repaired. Other wise,
simply buy a new board.

Sorry if that wasn't the answer you were seeking for.

http://webpages.charter.net/jamie_5";

.

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