Toshiba TV29C90 problem; Image fades to black...

[Jumpster Jiver]

J.P. wrote:

I have a Ohmite VT4-F varible voltage unit that was taken apart when I
got it. It is wired but just disassembled. It appears the fuse socket
is broken and had no continuity between the front of the fuse under
the cap and the terminal. The fuse has continuity. I would like to
know if someone can tell me how to test this thing to see if it is
good. TIA... J.P.


The later models had a plastic fuseholder that would crack if its nut
was overtorqued or if the fuseholder was dinged. Try wiggling the
back of the fuseholder (with power off, of course). If you have to
replace it, it's a standard size.

Now, for troubleshooting, unplug, open the front panel, and have the
whole front panel assembly laying on the bench. Just to begin with,
look at the lapped surface of the windings (where it meets the brush)
and look for burn marks or discontinuities. Now turn the control from
0 to 140 and back while feeling the dial and looking at the brush. See
that the dial turns smoothly, and the brush does not catch throughout
the range.


Now use an ohmmeter to look for continuity through the circuit. Black
from the line cord through the fuse and through the VT to L@ and to
the output wire (power off, again).


Having passed so far, get a clean lint-free cloth and some pure
alcohol (NOT 70% rubbing alcohol). Moisten the cloth with the
alcohol, and gently wipe the lapped wire mating surface. (This is a
PM procedure that should be performed periodically -- carbon crumbs
from brush wear are a major killer of VTs.) Let 'er dry.


Now, replace the cover, and place the wiper at around the midpoint. I
forget the wire numbers on the front panel of the VT itself, but you
should be able to see there's an L1/Hot/black (from the fuse), and
L2/Neutral/white from the line cord. You've also got a green ground,
which is connected to the chassis, and the output, which goes to the
L1
connect on the front output outlet. You should put your meter across
the outlet, and plug it in. You should see about 70V. When you dial
the control from min to max, you should see around 0 to 140V (it will
be a bit high with no load).


If you don't see an output, and you are somewhat adept at working with
line voltage, you can do the above with the case cover open. Just
trace the voltage relative to the white wire/L2. Be careful, as line
voltage is present on all parts inside the box. If the voltage isn't
there, there's an open. Simple. Fixing it, though, can be a problem.

I'd guess your VT winding wire has probably opened up somewhere along
the lapped surface. That's not economical to repair, because you'd
have to first remove the varnish, then strip off the wire, rewind,
revarnish, and relap the windings. In days of yore, Ohmite used to
rewind the larger units, but not any more. Less likely but possible
is lack of contact between the brush and the lapped surface. This
happens from wear, as well as the brush falling out.


If you have a newer one, it's possible you have a Staco variable
transformer inside the unit. If you want, you can still get the Staco
replacement AFAIK -- I believe Staco still sells it. The brush itself
is not replaceable.


Remember, just trace continuity, then the voltage. Where continuity
or the voltage disappears is where it's open. And do be careful --
it's never a good day to dance the 60 hertz.

Oh, yes -- would you like fries with that? ;-)


Good luck
Chris


Chris, I missed your reply somehow and just found it on Google.Thanks
for the answer.The problem that I now have, since this was already
partially disassembled, is that there was no wire from the fuse to the
circuit board (and I do not know which terminal to attach one to), and
there is no apparent conncetion between the dial and the circuit board
(and I do not know what type of wire nor how it conncets to the
dial).Any ideas here? Thanks again. J.P.

Thanks but I was not the OP, I just left one of the sort replies.

 

[jakdedert]

mc.preist@gmail.com wrote:

It doesn't work..
How much should I tap?!

Sorry, thanks.


It should be mentioned that ac adapters are dime a dozen on eBay. I've

always been able to replace mine for less than $20. A search on your
model # will pull up more auctions than you can imagine.

Beware a low price coupled with high shipping....

jak

 

[jakdedert]

mc.preist@gmail.com wrote:

I tried it.. I'll try more..

The thing is, the place where the cord comes out of the adapter gets
hot and makes a strange noise (high pitched hiss). The green light does
not come on and the charger does not charge my Laptop.

Now Dell gave up on me.. a94in
And I'm sure the problem is the cord, for when I move it - the sound
changes.


It's broke, for sure and you might not even be able to fix it. Get

another one ASAP (see my post about eBay). Even if you get it fixed, a
second adapter (to keep in your computer bag, leaving the other at your
desk) is almost essential these days. They blow up, get lost or
stolen...two is a minimum, IMO.

Get another one...maybe two.

jak

 

[jakdedert]

Kris Shaw wrote:

Hello,

On Tue, 02 Jan 2007 14:03:51 -0600, jakdedert
jakdedert@bellsouth.net> said to us:

I got this one at a thrift store for a few bucks, minus the adapter. If
anybody has this model, or a similar one, can you look at it for the
volts/amps/polarity...ac/dc?

Amazon has some technical specs:

http://www.amazon.com/AT-962-2-Line-Duplex-Speakerphone/dp/tech-data/B00000JB80/ref=de_a_smtd/103-6755983-1174214

I'm sorry. I looked at several 'shopping' sites and didn't find

anything...not like me. Google is my friend.

OTOH, I might have guessed, given the above. I just didn't want to
chance it....

Thanks

jak

Regards,

Kris.

 

[Allodoxaphobia]

On 2 Jan 2007 13:39:30 -0800, hrhofmann@att.net wrote:

I always use a gentle cut with a hacksaw when the drop and kick method
doesn't work. I start at one corner and hacksaw thru till I get air.
Then I use a strong screwdriver to pry the rest of the case open.
Sometimes you have to hacksaw partway through the case all the way
around before the screwdriver will pop the case open. It all depends on
how cheap the case is made. You don't have much to lose, just be sure
the power wall wart is unplugged when you do this <GG>.

H. R.(Bob) Hofmann

PhattyMo wrote:
mc.preist@gmail.com wrote:
It doesn't work..
How much should I tap?!

Sorry, thanks.


You need to "tap" it,not tap it..
Give the sucker one good *whack*.
The "diagonal" method has worked for me before..

(I hate those damn glued-together-brick cases!)

I usually soak it for an hour or so in the freezer.
Then I set a pocketknife along the crack of the solvent-glued seam and
tap _that_ with a wee little ballpeen hammer.
Go right 'round the thing 2 or more times.
By then you should have one section of the seam that is willing to
cooperate for you.
And, by then, the case should be a little warmer to permit you to then
use the knife blade as a pry under the now-loosened seam.

HNY
Jonesy
--
Marvin L Jones | jonz | W3DHJ | linux
38.24N 104.55W | @ config.com | Jonesy | OS/2
*** Killfiling google posts: <http//jonz.net/ng.htm>

 

[William R. Walsh]

Hi!

Give the sucker one good *whack*.
(I hate those damn glued-together-brick cases!)

Sometimes even that isn't enough. I had a bad Compaq AC adapter from my old
LTE 5000 laptop. Something inside had been sizzling and finally went bang.
The whole thing smelled pretty bad. I didn't think it would be fixable, as
the wire coming out was already badly frayed and didn't make contact most of
the time anyway. All I wanted to do was open it up to see what had gone
wrong.

I started gently enough with a small mallet. Then I tried a hammer. It went
downhill from there quickly. Even several good whacks on concrete from a
distance wouldn't open the thing. I even tried driving over it, and that
finally got it to start coming open. Of course, by that point, the insides
were not in good shape.

William

 

[webpa]

Ancient_Hacker wrote:

To test for a vacuum leak, just run the engine at idle and spray all
over with anything flammable-- WD-40 is probably the safest. I wouldnt
spray starting fluid, it's a bit too quick to evaporate and mighty
explosive and intoxicating too. The old VW Rabbits would get
hardening of the injector grommets and leak like crazy-- five seconds
of spraying and you knew for sure they were leaking as the idle would
speed up whenever you sprayed.

To test the injectors, pull the wires off them one at a time. No wire
means no injection which should result in lots of engine vibration but
the NOx should drop if the injector's been faulty.

Is the engine hard to start after it's been sitting off for a few
minutes? That might point to drippy injectors. A can of injector
cleaner can't hurt to try.

Good luck.

Been through all this with an '86 Fiero. Flushed, adjusted, then
replaced EVERYTHING...every sensor, vacuum hose, valve, and device...to
no effect. In the end, it took a new catalytic converter...which cost
all of US$86, installed. By Midas Mufflers. About 1/4 of what I'd
spent on the other parts. So: Don't jump to conclusions.

 

[Dan]

"PhattyMo" <PhattyMo@nospam.gmail> wrote in message
news:459acec3$0$497$815e3792@news.qwest.net...

Dan wrote:
I was recently given a portable DVD player for signing up to DirctTV. I
didn't expect it to be the best one on the market (smallish screen for 1
thing) but I thought it would be good for watching a movie during
frequent 2 hour plane trips I have to take. Plays fine, decent picture,
BUT the batteries crap out after a little over 1 hour (you'd think at a
minimum the thing would be good for one 2 hour film). So I opened the
battery pack & as I suspected, found 7 NiMH AA cells, marked 1300 mah. I
see that NiMH AA's are available up to around 2700 MAH. Swapping out the
cells is straightforward, but I'm wondering if the current charger would
be up to the task of feeding them. Looks like a fairly decent circuit
(multiple ic's, anyway) which includes a thermistor taped to the cell
pack. Whether this is how the circuit senses a full charge or whether
it's an overheat detector, I don't know. But again, the circuit does
appear to be a bit more sophisticated than those I've seen for drills,
etc, which do rely on the crude temp method to indicate a full charge.
Might this charger be able to handle cells of 2X the capacity of those
the unit came with? How could I test this, short of actually buying &
installing the higher amp cells? A measure of charging current with the
present cells, maybe?

TIA

Dan


The charging circuit itself _probably_ limits the current to some "safe"
value,so there's _probably_ no worries about frying the
charger,overcharging the cells,etc.
It will just take 2x as long to fully charge..

Thanks for the replies, I'll give it a try.

Dan

 

[dkuhajda@locl.net]

mc.preist@gmail.com wrote:

Does anyone know?!
I have an Inspiron with a 90W adapter. Do you know how to open this
adapter, I have to repair the cord.

Thank you in advance!
Igor.

Which AC adapter? Dell has had a bunch recalled due to this very
defect. Check the Dell recall website or CPSC.gov to get the link.

 

[Homer J Simpson]

<mc.preist@gmail.com> wrote in message
news:1167767104.452436.120810@i12g2000cwa.googlegroups.com...

Does anyone know?!
I have an Inspiron with a 90W adapter. Do you know how to open this
adapter, I have to repair the cord.

Failing any better way, whack it on cement until it breaks. It'll be easier
to fix than if you saw it open.







--

 

[Malissa Baldwin]

mc.preist@gmail.com wrote:

Does anyone know?!
I have an Inspiron with a 90W adapter. Do you know how to open this
adapter, I have to repair the cord.

Thank you in advance!
Igor.

What makes you think that it's the cord. It could be a problem in the
Laptop. But if you still want to get it open a pnematic drill often
works wonders.

 

[W. Watson]

W. Watson wrote:

In the last week, we've noticed that channel 3 has a very apparent noise
on it when it is on. If DirecTV is turned on, then the noise goes away.
We have two TVs on DirecTV and a third downstairs, which we can switch
over to DirecTV.
#1: Living room -- DirecTV
#2: Bedroom -- DirecTV
#3: Downstairs -- switchable to DirecTV

I've turned off my PC eqpt near #1, but no change. We've turned off a
few more household gadgets with no change.

This morning the noise is no longer on #2. No noise on #3. I don't
believe we examined #3 prior to a few minutes ago when I did check it.
We took #1 completely off--no antenna connection or power, and will
leave it that way for the rest of the day. It's the newest TV we have. A
Sharp 19" LCD.

I suspect the culprit will be the Sharp. Comments? The loss and gain of
the simultaneity of the noise on #1 and #2 to just #1 seems very odd.

Solved. When we were playing a DVD on the TV, I asked my wife to put the
subtitles on. She went to the TV menu, and somehow accidentally hit SAP.
That's what caused the noise. BTW, what's SAP?

 

[Ken Weitzel]

W. Watson wrote:

W. Watson wrote:

In the last week, we've noticed that channel 3 has a very apparent
noise on it when it is on. If DirecTV is turned on, then the noise
goes away. We have two TVs on DirecTV and a third downstairs, which we
can switch over to DirecTV.
#1: Living room -- DirecTV
#2: Bedroom -- DirecTV
#3: Downstairs -- switchable to DirecTV

I've turned off my PC eqpt near #1, but no change. We've turned off a
few more household gadgets with no change.

This morning the noise is no longer on #2. No noise on #3. I don't
believe we examined #3 prior to a few minutes ago when I did check it.
We took #1 completely off--no antenna connection or power, and will
leave it that way for the rest of the day. It's the newest TV we have.
A Sharp 19" LCD.

I suspect the culprit will be the Sharp. Comments? The loss and gain
of the simultaneity of the noise on #1 and #2 to just #1 seems very odd.

Solved. When we were playing a DVD on the TV, I asked my wife to put the
subtitles on. She went to the TV menu, and somehow accidentally hit SAP.
That's what caused the noise. BTW, what's SAP?

Hi...

Second Audio Program? (another language)

Take care.

Ken

 

[mc.preist@gmail.com]

It's the cord because when I plug the adapter to the source, it makes a
noise - and when I mess with the cable, the sound changes. The problem
seems to be at the origin of the cable near the adapter.

Anyway.. This case is dead. Dell won't help, because I'm in South Korea
and they don't support my Inspiron 9400/E1405.
I'll try eBay!
Thanks a lot!

 

[mc.preist@gmail.com]

I actually found out it's dangerous to open the adapter.
http://groups-beta.google.com/group/comp.sys.laptops/browse_thread/thread/e22955849b556762/#

 

[mc.preist@gmail.com]

I didn't know it might be dangerous to open it...
http://groups-beta.google.com/group/comp.sys.laptops/browse_frm/thread/e22955849b556762/f2a2b8bd0024aac9#f2a2b8bd0024aac9

 

[Arfa Daily]

"N Cook" <diverse8@gazeta.pl> wrote in message
news:endv7f$gks$1@inews.gazeta.pl...

Ron(UK) <ron@lunevalleyaudio.com> wrote in message
news:AN-dnZEdKJSD5QfYnZ2dnUVZ8qijnZ2d@bt.com...
N Cook wrote:
J M Goodey <jgoodey@zetnet.co.uk> wrote in message
news:3130303035313136459A45DA77@zetnet.co.uk...
The message <endbs0$jmq$1@inews.gazeta.pl
from "N Cook" <diverse8@gazeta.pl> contains these words:

The owner managed to blow all 4 in a cab by overdriving them. 4x 12
inch
,
16 ohm, 60W , maybe replacements only up to 5KHz and add a tweeter or
two
I have a large useless cab cluttering up the place until he can find
something to replace. As they're obviously prepared to tolerate nasty
noises
while progressively failing they presumably don't need hi fidelity ,
just
cheap enough or I can see this cab going on a bonfire.
Yes, i've googled ,but 120 quid for 4 would seem to be the breakpoint
and
can find nothing like that.
--
Diverse Devices, Southampton, England
electronic hints and repair briefs , schematics/manuals list on
http://home.graffiti.net/diverse:graffiti.net/




Rapid Electronics of Colchester (of whom I have no commercial
connection)
sell 12" 200w speakers for about Ł20:00 plus VAT. I have used several
of
them in situations similar to yours.
www.rapidelectronics.co.uk

--
Jocelyn
jgoodey@zetnet.co.uk
Tetigisti acu. (Titus Maccius Plautus 254 - 184BC)



I see a rock and a hard place coming up.
I would replace the 4 16 ohmers with 2 8 ohmer 100 watts and selector
switch
bypassed, but for the same 4 bottle, 120W amp would that be the same
oomph,
as they term it. ?
Although amp and cab are Crate make they obviously were not made as a
matched pair as amp has 16/8 ohm output setting and cab is 4 / 16 ohm
setting. I suspect they'd been running for some time as I received them
,
amp set at 16 ohm and cab set as 4 ohm , so they certainly won't be
getting
the same oomph as amp at 16ohms and cab at 16 ohms.

Providing the speaker load matches the amplifier, you should get the
same output, but the apparent volume depends on the sensitivity of the
speakers - most of these so called 'high power speakers are notoriously
insensitive. 'Classic' guitar speakers such as the Celestion G12H etc,
were/are very sensitive and have corrugated cones designed to 'trash
out' at high volume without destroying the speaker.

Is there a way of perhaps saving stressing output matching transformer
in
the case of the speaker load going open circuit?
eg a high watt 50 ohm resistor in parallel with each speaker of the
serised
8 ohm speakers so the load does not go totally o/c and some sound until
replaced , rather than zero sound . Extra permanent resistor load would
be
un-noticeable I'd have thought.

Some of the Selmer amps had a high wattage resistor across the output
jacks to help in absorbing some of the energy in the case
of a loudspeaker cable becoming unplugged. That`s probably the safest
way to go.

Before you put too much money into this cabinet, do you realise that you
can buy a Behringer 400 watt 4x12 for little over Ł200, or much less if
you shop around?

Ron(UK)

I'll probably recommend 4x 8 ohms permanently wired as seriese / parallel
8
ohm and amp switched to 8 ohm with some 50 ohm Rs, at least if they switch
amp to 16 ohms won't cause problems other than lower output.
That is 2 seriesed in parallel with 2 seriesed for best failure mode
outcome

Buying new box comes up against sentiment, it won't have a gaudy big
"gold"
logo saying CRATE on the front , the word crate means just shipping crate
in
USA presumably does not have the connotation of "heap of junk" as it does
in
the UK


Two things spring to mind here. The first is to just ask the owner what

exactly he does ( or wants to do ) with the setup. If he is looking to find
some very high output 'sweet-spot' sound from the rig, then you will need to
be concerned about output level, impedance matching, and the overall sound
you are going to get from replacement drivers. It is also important to know
the instrument that's going to be played through it, and how. It's no good
having a set of stiffly suspended lead guitar speakers, if it's going to
have a bass guitar put through it. Likewise, a Yamaha organ at afternoon tea
dances, is a world away from a synthesiser at a rock concert. I have these
conversations all the time with musicians, and they can be a fickle lot, so
best to understand what's needed right from the off.

The second thing to remember is that speaker impedance is by no means an
absolute. It is a figure quoted for a particular speaker with a particular
set of test drive characteristics, and is especially sensitive to frequency.
If the owner is never intending winding the rig right up to full power, then
8 ohms of amp into 4 ohms of cab, is not going to be any particularly big
deal - especially for a valve amp. The output tranny will stand considerable
overload abuse anyway in my experience, and you've got to work hard to
damage a set of 4 valves through over-dissipation at their anodes. A 100
watt amp doesn't come close to delivering an average power of 100 watts to
the speakers. It might just get there on peaks. Doing it the other way
around, will also not usually cause a problem in the situations that this
equipment is normally used in. 8 ohms of amp into 16 ohms of cab, *may*
appear a little quieter, but even this is not a given. If the owner is not
going to be trying to squeeze every last dB of sound level out of the rig,
then he just needs to turn it up a bit to compensate.

In theory, both conditions will result in a deviation from the 'ideal'
sound, and I'm sure that there are audiophiles on some of the audio groups,
who would tell you that such a mis-match is a cardinal sin, and that they
would be able to hear it, but trust me - you, I or the average modern
musician, would not hear anything untoward. So the bottom line is yes, by
all means be aware of the *potential* problems, but don't worry yourself
into an early grave about them. Equipment mismatches in the rock musician
world, is the norm rather than exception ( well, perhaps not quite, but you
take my point ...). Talk to the owner !

Arfa

 

[Mark D. Zacharias]

Malissa Baldwin wrote:

F*CK SONY F*CK

C'mon Malissa, don't beat around the bush - tell us what you really think!

Mark Z.

 

[Meat Plow]

On Tue, 02 Jan 2007 12:11:24 -0800, mc.preist@gmail.com Has Frothed:

I tried it.. I'll try more..

The thing is, the place where the cord comes out of the adapter gets
hot and makes a strange noise (high pitched hiss). The green light does
not come on and the charger does not charge my Laptop.

Now Dell gave up on me.. a94in
And I'm sure the problem is the cord, for when I move it - the sound
changes.

The cord would not hiss when it's broken.


--
Pierre Salinger Memorial Hook, Line & Sinker, June 2004

COOSN-266-06-25794

 

[mc.preist@gmail.com]

On Jan 3, 8:45 pm, Meat Plow <m...@meatplow.local> wrote:

On Tue, 02 Jan 2007 12:11:24 -0800, mc.pre...@gmail.com Has Frothed:
The cord would not hiss when it's broken.

It hissed before a couple of times, and if I moved the cable - it would
work properly..
But at one point it never stopped hissing whatever I did.