G
Guest
Posting this for the benefit of others ( Google Groups search etc.)
We purchased a Black and Decker TRO-360 Toaster Oven about 4 months
ago and recently the toast switch failed. The switch does not stay
down. According to the reviews at Amazon this is a common problem.
Many people in the reveiw section for this item are complaining of the
same problem. I decided to try and repair the oven as I have an
under counter bracket and heat shield for it which is very handy.
The switch is held down by an electromagnet that is driven by a small
timer board inside the oven. The timer board converts the setting of
the toast setting pot to a digital value and then uses a 'count-down'
type digital timer to control the toasting time. The part that
failed on the timer board in ours was a 6.2V Zener Diode part number
1N4735A that provides power to the CD4060 CMOS counter chip used as a
timer. The zener failed open and was only providing only about 1V to
the circut instead of the 6.2V required. It was an easy fix and now
it works like brand new again. Because of the nature of the circuit,
it was hard for me to trace the problem to this little guy. It is
the only zener on the little circuit board. I had a 6.8V 1W Zener in
my junkbox and because the CMOS chip is tolerant of a wide range of V
I used that instead of the factory part. It seems that the timer
maybe runs a bit faster now but it works just fine. Just need to set
the toast setting knob a bit lower.
I am posting this because I searched the Internet expecting to find a
technical note or release from B&D about this problem or maybe a post
from someone else. No luck! I suspect that this is probably what is
failing on all of them and a defect from the factory. Would be
curious if you own one of these ovens with this problem, please email
me.
Have yet to have it make any toast that is worth selling on Ebay but
still hoping.
We purchased a Black and Decker TRO-360 Toaster Oven about 4 months
ago and recently the toast switch failed. The switch does not stay
down. According to the reviews at Amazon this is a common problem.
Many people in the reveiw section for this item are complaining of the
same problem. I decided to try and repair the oven as I have an
under counter bracket and heat shield for it which is very handy.
The switch is held down by an electromagnet that is driven by a small
timer board inside the oven. The timer board converts the setting of
the toast setting pot to a digital value and then uses a 'count-down'
type digital timer to control the toasting time. The part that
failed on the timer board in ours was a 6.2V Zener Diode part number
1N4735A that provides power to the CD4060 CMOS counter chip used as a
timer. The zener failed open and was only providing only about 1V to
the circut instead of the 6.2V required. It was an easy fix and now
it works like brand new again. Because of the nature of the circuit,
it was hard for me to trace the problem to this little guy. It is
the only zener on the little circuit board. I had a 6.8V 1W Zener in
my junkbox and because the CMOS chip is tolerant of a wide range of V
I used that instead of the factory part. It seems that the timer
maybe runs a bit faster now but it works just fine. Just need to set
the toast setting knob a bit lower.
I am posting this because I searched the Internet expecting to find a
technical note or release from B&D about this problem or maybe a post
from someone else. No luck! I suspect that this is probably what is
failing on all of them and a defect from the factory. Would be
curious if you own one of these ovens with this problem, please email
me.
Have yet to have it make any toast that is worth selling on Ebay but
still hoping.