Toshiba TV won't turn on, however can manually power it
Ken Bell
In article <4ulrhg$c...@news2.nkn.net>, Colin Kraft <ckr...@fastlane.net> wrote:
>Hi folks,
>
>I have a 10 year old Toshiba TV that does not power on either with the
>remote or the old-fashioned way. It doesn't click or do anything.
>However, there is a relay right next to the first AC fuse (where the
>cord comes in) and if I manually hold this relay shut, the TV powers
>up fine! Any suggestions on this one?
I'd think that if the control leads on the relay are getting power
(usually around 10 V DC, probably written on the relay itself) and
it doesn't close, then the relay is faulty. Otherwise, the circuit
that should be supplying the control voltage to the relay is suspect.
--
Ken Bell :: ken...@panix.com :: (212) 475-4976 (voice)
======== :: sy...@giss.nasa.gov :: (212) 678-5516 (voice), 678-5552 (fax)
Colin Kraft
Hi folks,
I have a 10 year old Toshiba TV that does not power on either with the
remote or the old-fashioned way. It doesn't click or do anything.
However, there is a relay right next to the first AC fuse (where the
cord comes in) and if I manually hold this relay shut, the TV powers
up fine! Any suggestions on this one?
Thanks,
-C
Colin Kraft
ckr...@fastlane.net
Sam Goldwasser
There is probably a standby power supply running all the time. There is
a good chance it is bad - power transformer, etc.
--- sam
In article <4ulsm9$l...@panix2.panix.com> ken...@panix.com (Ken Bell) writes:
In article <4ulrhg$c...@news2.nkn.net>, Colin Kraft <ckr...@fastlane.net> wrote:
>Hi folks,
>
>I have a 10 year old Toshiba TV that does not power on either with the
>remote or the old-fashioned way. It doesn't click or do anything.
>However, there is a relay right next to the first AC fuse (where the
>cord comes in) and if I manually hold this relay shut, the TV powers
>up fine! Any suggestions on this one?
I'd think that if the control leads on the relay are getting power
Sam Goldwasser
> I have a 10 year old Toshiba TV that does not power on either with the
> remote or the old-fashioned way. It doesn't click or do anything.
> However, there is a relay right next to the first AC fuse (where the
> cord comes in) and if I manually hold this relay shut, the TV powers
> up fine! Any suggestions on this one?
Check to see if you get power across the relay coil when you press the on
button.
If you do, the relay is bad.
If you don't, check the standby power supply and work forward from there.
Its power transformer may be bad. You don't have any master 'vacation'
switch you forgot to turn on by any chance?
--- sam
Colin Kraft
s...@stdavids.picker.com (Sam Goldwasser) wrote:
I found that if I short a nearby transitor's base to collector then
the relay closes and the set powers up. I replaced the transistor but
that was not the problem.
It doesn't have any master vacation switch. The set was damaged
during a storm. I was amazed to find that the fuses were all still
good in the unit and nothing was visibly damaged.
I don't have the schematics so I'm not sure what the standby power
supply consists of.
-C
Colin Kraft
ckr...@fastlane.net
Sam Goldwasser
1. You could install a manual switch and be done with it.
2. Get the Sams' Photofact for the set or a service manual. The standby
supply may be a power transformer/rectifier/filter cap affair. You should
be able to trace from the line cord and find it. The transformer may be
dead, etc. There might even be a blown fuse.
--- sam
Charley S. McCue
Colin Kraft wrote:
>
> I found that if I short a nearby transitor's base to collector then
> the relay closes and the set powers up. I replaced the transistor but
> that was not the problem.
>
> It doesn't have any master vacation switch. The set was damaged
> during a storm. I was amazed to find that the fuses were all still
> good in the unit and nothing was visibly damaged.
>
> ckr...@fastlane.net
Check for a diode across the relay windings. If it is shorted, this is a
problem and may be the problem. Replace it if it is shorted.
Another problem after that or instead of that may be no power to drive
the relay but you seem to prove the power is ok when you got the relay
to energize.
Hope this helps.
Sam Goldwasser
> Colin Kraft wrote:
> >
> > I found that if I short a nearby transitor's base to collector then
> > the relay closes and the set powers up. I replaced the transistor but
> > that was not the problem.
> Check for a diode across the relay windings. If it is shorted, this is a
> problem and may be the problem. Replace it if it is shorted.
He is able to energize the relay. I would suspect the standby power supply
or controller.
--- sam