This Canon ImageClass D660 printer/scanner/fax was subjected to a power
surge. An open neutral line on the customer's street knocked out a lot of
equipment in a lot of homes. I was able to locate the damaged power supply
board by following the fine aroma of charred components. The result of the
damage was that it just needed a few capacitors and a T4A fuse. I powered it
back up and was able to print a test page ok. However, before I proceed
putting this all back together to check everything else, I noticed that
there's an l.e.d. on the system control(?) board which has an amber l.e.d.
that continuously blinks like a turn signal.
http://webpages.charter.net/mrfixite...inking-led.jpg

Does anyone know if this is normal?

Thanks for your reply.
--
David Farber
Los Osos, CA

On Monday, October 27, 2014 1:07:24 PM UTC-5, David Farber wrote:
This Canon ImageClass D660 printer/scanner/fax was subjected to a power
surge. An open neutral line on the customer's street knocked out a lot of
equipment in a lot of homes. I was able to locate the damaged power supply
board by following the fine aroma of charred components. The result of the
damage was that it just needed a few capacitors and a T4A fuse. I powered it
back up and was able to print a test page ok. However, before I proceed
putting this all back together to check everything else, I noticed that
there's an l.e.d. on the system control(?) board which has an amber l.e.d.
that continuously blinks like a turn signal.
http://webpages.charter.net/mrfixite...inking-led.jpg

Does anyone know if this is normal?

Thanks for your reply.
--
David Farber
Los Osos, CA

It's probably a watchdog circuit. Used to indicate proper operation. If it stops blinking, it means the processor is locked up. Perfectly normal.

junebug1701 wrote:
On Monday, October 27, 2014 1:07:24 PM UTC-5, David Farber wrote:
This Canon ImageClass D660 printer/scanner/fax was subjected to a
power surge. An open neutral line on the customer's street knocked
out a lot of equipment in a lot of homes. I was able to locate the
damaged power supply board by following the fine aroma of charred
components. The result of the damage was that it just needed a few
capacitors and a T4A fuse. I powered it back up and was able to
print a test page ok. However, before I proceed putting this all
back together to check everything else, I noticed that there's an
l.e.d. on the system control(?) board which has an amber l.e.d. that
continuously blinks like a turn signal.
http://webpages.charter.net/mrfixite...inking-led.jpg

Does anyone know if this is normal?

Thanks for your reply.
--
David Farber
Los Osos, CA

It's probably a watchdog circuit. Used to indicate proper operation.
If it stops blinking, it means the processor is locked up. Perfectly
normal.

Thanks for that explanation. Everything seems to be working fine. I'll
reassemble it and stop worrying about it. :-)

--
David Farber
Los Osos, CA

On 30/10/2014 15:48, David Farber wrote:
junebug1701 wrote:
On Monday, October 27, 2014 1:07:24 PM UTC-5, David Farber wrote:
This Canon ImageClass D660 printer/scanner/fax was subjected to a
power surge. An open neutral line on the customer's street knocked
out a lot of equipment in a lot of homes. I was able to locate the
damaged power supply board by following the fine aroma of charred
components. The result of the damage was that it just needed a few
capacitors and a T4A fuse. I powered it back up and was able to
print a test page ok. However, before I proceed putting this all
back together to check everything else, I noticed that there's an
l.e.d. on the system control(?) board which has an amber l.e.d. that
continuously blinks like a turn signal.
http://webpages.charter.net/mrfixite...inking-led.jpg

Does anyone know if this is normal?

Thanks for your reply.
--
David Farber
Los Osos, CA

It's probably a watchdog circuit. Used to indicate proper operation.
If it stops blinking, it means the processor is locked up. Perfectly
normal.

Thanks for that explanation. Everything seems to be working fine. I'll
reassemble it and stop worrying about it. :-)


I never expected to see a blinking LED inside (nothing seen of them on
the outside) an audio amp. Suspecting it may sometimes be possible to
end up with a clicking sound coming over the audio, via shared ground
routes or whatever - but there are such blinking LEDs in normal operation