Toshiba TV29C90 problem; Image fades to black...

On Mon, 01 Sep 2003 10:36:13 -0700, Jeff Liebermann
<jeffl@comix.santa-cruz.ca.us> wrote:

On 1 Sep 2003 08:28:41 -0700, bigcat@meeow.co.uk (N. Thornton) wrote:

A customer gets 4 used TVs from dealer B, one after the other. Every
one of them dies within a week, thats the reason for the replacements.
Customer A is pretty unhappy with dealer B, blaming their duff
products.

I should point out that this story smells like a hoax because of the
lack of make, model, and numerical details. However, I'll treat it
seriously (for no obvious reason). I also don't know of any dealer
that would replace 4ea TV's under warranty. One is the norm, two for
good customers, but not three replacements.

It would have been helpful if you supplied some details such as the TV
makes and models, as well as the results of any post mortem analysis.
Some clues as to the exact desciption of "dead" would be helpful.

I'll assume that the sets are dead as in no power supply or no
picture. A short list of possibles are:

1. Major power glitches via the AC power.
2. Faulty ground on AC power.
3. Static electricity fries circuitry when touched.
4. Ionizing (nuclear) radiation breaks down circuitry. Is the owner a
nuclear power station employee that takes his work home?
5. EMP (Electro Magnetic Pulse). Proximity to large pulsed RF power
such as high power RADAR.
6. EMF (Electro Magentic Field). Proximity to a large magnetic or
electric field such as the transformer on an X-ray machine.
7. High voltage. Is there an operational Tesla coil in the house?
8. High power microwaves. Is someone experimenting with a microwave
oven with the interlock disabled and pointed at the TV set?

Bad neutral connection in the panel, causing the voltage to swing up?
AC or DC voltage on the antenna connection?

 

[petrus bitbyter]

"N. Thornton" <bigcat@meeow.co.uk> schreef in bericht
news:a7076635.0309010728.3d0f65b4@posting.google.com...

Hi. A true life conundrum for you.


A customer gets 4 used TVs from dealer B, one after the other. Every
one of them dies within a week, thats the reason for the replacements.
Customer A is pretty unhappy with dealer B, blaming their duff
products.

Customer A goes to dealer C, and tells story of woe. Customer wants a
TV, but is understandably afraid to buy. Dealer C offers to do 2
things:
1. investigate their house to search for any possible cause for this,
and if none is found,
2. to offer 3 month guarantees with any used set sold. Any fault on
the set, full refund.

So, the house survey reveals no cause. No cat peeing, no vase of
flowers on the TV, no damp problem, no TV falling off its stand, no
rugs to put on the TV vent grills, no sign of deranged inhabitants, no
diesel generator, no invertor, no spraying with water based aerosols,
nothing. So customer goes home with dealer C's guaranteed used TV.
Dealer C is full of confidence, both thinking that dealer A must have
been a badun.

But things are not as they seem. After 3 days a call comes in: the TV
doesn't work. Van dispatched with replacement TV, and the faulty one
is subject to thorough examination back at dealer C's premises. Again,
no external issues are found. No damp, no patch marks, no smell of cat
pee, no screws undone, no scratches from the TV being knocked about,
nothing.

With in a week, another call. TV number 6 is dead now. Feeling that
sinking feeling, the van is dispatched one last time. We have no
replacement TV in stock, we'll get yours done within 2 days.

Same examination, and again no cause found. Dealer C decides at this
point to refund the money, and advises customer to rent instead, from
their main competitor.


The only data I dont have is the failure modes for TVs 5 and 6. To
this day no-one knows why those 6 TVs died. What could have happened
in this tale of the Bermuda TVriangle?


Regards, NT

LS,

Havig no real information about this case, we can speculate through all
eternity. Here is one: Did the customer have the bad habit of switching the
set off and on rapidly? A lot of TVsets, even new ones, will not survive
this treatment for long.

pieter


---
Outgoing mail is certified Virus Free.
Checked by AVG anti-virus system (http://www.grisoft.com).
Version: 6.0.511 / Virus Database: 308 - Release Date: 18-8-2003

 

[Bob Minchin]

Walter Craig wrote:

Can I regulate the 240v input of a mains transformer in order to set the
output to 7/14v of a 18v-40amp battery charger.
Without using wirewound resistance its wastfull and warm.
Thanks.
Cutty.

How about reducing the inpt voltage with a variable transformer (variac)?
Once you have the correct output voltage , a couple of screws will fix the
setting of the variac or add a soldered on tap to the variac winding so you
can use it for other things in variable mode.

Bob

 

[ajb]

On Mon, 1 Sep 2003 21:10:55 +0100, "Walter Craig"
<walter@craig8607.freeserve.co.uk> wrote:

Can I regulate the 240v input of a mains transformer in order to set the
output to 7/14v of a 18v-40amp battery charger.
Without using wirewound resistance its wastfull and warm.
Thanks.
Cutty.

You could use a Variac (variable voltage transformer) on the input,
though unless you have one handy which would handle several hundred
watts (or _never_ turn it up too much on load!) it might be a bit
expensive. But surplus items do sometimes turn up cheap.....

And you'd lose some of the regulation and 'stiffness' of your charger
anyway, whatever method you used, though that might not matter.

AJB
--

Un-stop the address to reply, please.

If the 'self' is an illusion, who is being fooled?

 

[N. Thornton]

Hi peoples.


I'll answer you all as best I can. I know many details, but not all.

What were the failures of sets 1-4? When you say the sets "died" are
they actually dead as in no picture or sound?

I never saw them so dont know. That would certainly be useful data. I
saw sets 5 and 6, and there was no sign of life, nothing. I got to see
them enough to see there was no tampering, peeing, spilling, etc, but
thats all.

No models & brands?

No, they were assorted used 24" sets, various makes.

No description of fault and what was failed parts?

Only info I have is they were all 'dead', no sign of life. Might
suggest a power issue - but loptr failure was more common than PSU
fails on those (discrete component) TVs. And a shorted loptr would
take down the psu.

There are no mystery IMHO. There is external causes if there is
string of duds in a row.

I agree. If we go with a normal expected failure rate of 20%, the odds
of it being chance are 1 in 15000.

Faulty electrical circuit (house),

I understand that could fry stuff in the US, but it could only cause
Vdrop here, which should be harmless.

lightning,

have to be a heck of a lot of it! I think thats most unlikely. Their
house wiring would be charcoal by the time 6 sets had gone, ditto the
neighbours.

dealer's shoddy tv shop;

The first supplier may well have been, but I know enough of this case
to know they were thorough second time round. Sets 5,6 came from a
sound dealer.

rare but happens, faulty equipment
hooked to that TV

Good point. But... I cant see any way a video could damage a TV. There
are no other external connections on those old sets. Putting mains up
the aerial socket would be harmless to the TV. The input capacitors
would just sit and smile.

or user.

Prime suspect! But how? No-one could figure anything.

Even shipper can be a problem.

Maybe so for sets 1-4, but not 5,6. I knew the business involved, the
2nd dealer, and was asked in to help de-mysterise, without success.
Both sets 5 and 6 were checked at installation.

Try adding a surge protector on the power cord and add a stick-on
seal
to that connection to prevent tampering. At least the dealer can
determine if power spikes is a cause.

I think power spikes are not a problem, any consumer equipment has
sufficient filtering built in to protect itself. Especially stuff like
TVs and puters. Surge protectors have little effect by comparison. The
house was on a big estate, so any problems would have been shared all
round.

What about the polarity of the
power plugs?

wouldn't make any difference AFAICS.

I should point out that this story smells like a hoax because of the
lack of make, model, and numerical details.

We're talking low cost used sets, so no-one cared what make and model
they were. It was just screen size and decade of manufacture that
counted.

I also don't know of any dealer
that would replace 4ea TV's under warranty. One is the norm, two for
good customers, but not three replacements.

Good point. The customer was really not the smart kind, so may well
have bought 2 of the first 4 sets, the other 2 being replacements for
those. But I dont really know. They could even have paid for 3 or 4.

It would have been helpful if you supplied some details such as the
TV
makes and models, as well as the results of any post mortem analysis.

I dont really have any more to give you. Second hand dealers dont
investigate things the way a manufacturer would. If the customer keeps
bringing stuff back, they dont serve em anymore. Thats it.

Some clues as to the exact desciption of "dead" would be helpful.
I'll assume that the sets are dead as in no power supply or no
picture.

yup.

1. Major power glitches via the AC power.

It would have to be truly major, and the house was on the same grid as
its neighbours: I did say look for generators, autotransformers etc,
nothing. Nor any evidence of anyone at the house who might have a clue
about anything like that. They really weren't the bright type.

2. Faulty ground on AC power.

would make no difference here.

3. Static electricity fries circuitry when touched.

Those sets aren't static sensitive AFAIK. Static on the cabs was
normal anyway, and never caused trouble.

4. Ionizing (nuclear) radiation breaks down circuitry. Is the owner
a
nuclear power station employee that takes his work home?

hehe, good one - though it sounds pertty unlikely. This guy was no
brainiac or anything.

5. EMP (Electro Magnetic Pulse). Proximity to large pulsed RF power
such as high power RADAR.

on a large housing estate, so pretty unlikely.

6. EMF (Electro Magentic Field). Proximity to a large magnetic or
electric field such as the transformer on an X-ray machine.

Nothing was found... would have to have been a fair distance away.

7. High voltage. Is there an operational Tesla coil in the house?

I did wonder, but no-one there showed anything like enough
intelligence to do something like that, and absolutely no sign of
anything suggesting any interest in electrics or tronics was found.

8. High power microwaves. Is someone experimenting with a microwave
oven with the interlock disabled and pointed at the TV set?

You never know! But a) its most unlikely, b) one would expect medical
consequences, and c) nothing was found to indicate any form of
electrical work/play of any kind at all.

Bad neutral connection in the panel, causing the voltage to swing up?

The UK isnt wired like that, so we dont get that problem.


Well, certainly some interesting ideas there, but I can't help
thinking the possibles are all very unlikely.

I half wondered about a malicious or sociopathic teenage neighbour
equipped with something homebrewed and dangerous, but lets face it,
its extremely unlikely, and I cant even think what apparatus would do
it.

I'm still mysterised. Maybe news2020 was right after all


Regards, NT

 

[Jason D.]

On 1 Sep 2003 15:48:05 -0700, bigcat@meeow.co.uk (N. Thornton) wrote:

Hi, Whew long one!

I'll answer you all as best I can. I know many details, but not all.

What were the failures of sets 1-4? When you say the sets "died" are
they actually dead as in no picture or sound?

I never saw them so dont know. That would certainly be useful data. I
saw sets 5 and 6, and there was no sign of life, nothing. I got to see
them enough to see there was no tampering, peeing, spilling, etc, but
thats all.

No models & brands?

No, they were assorted used 24" sets, various makes.

Uggh... I don't like this...!

Why is your job reported this without all the details, you gotta have
the paperwork with serial and models on them when they came in for
checks and estimate or warrenty repairs?

No description of fault and what was failed parts?

Only info I have is they were all 'dead', no sign of life. Might
suggest a power issue - but loptr failure was more common than PSU
fails on those (discrete component) TVs. And a shorted loptr would
take down the psu.

That's useless info to go on.

I agree. If we go with a normal expected failure rate of 20%, the odds
of it being chance are 1 in 15000.

Faulty electrical circuit (house),

I understand that could fry stuff in the US, but it could only cause
Vdrop here, which should be harmless.

lightning,

have to be a heck of a lot of it! I think thats most unlikely. Their
house wiring would be charcoal by the time 6 sets had gone, ditto the
neighbours.

Doesn't matter where 1v or 4kV as power sources. they all get fried
if lightning hits. Seen many of those.

But series of duds in a row is very suspicious and must be carefully
analyzed which means opening up the sets and take a look and note the
models. Frankly, I'm disappointed with this because we still have
nothing to go on so far.

dealer's shoddy tv shop;

The first supplier may well have been, but I know enough of this case
to know they were thorough second time round. Sets 5,6 came from a
sound dealer.

rare but happens, faulty equipment
hooked to that TV

Good point. But... I cant see any way a video could damage a TV. There
are no other external connections on those old sets. Putting mains up
the aerial socket would be harmless to the TV. The input capacitors
would just sit and smile.

Considered that? Intermittent house's open neutral wire especially in
cheap sets that has hot ground throughout the chassis, so power went
through wrong paths through RF connector or video inputs.
But I don't know what system is like for western 230V.

Prime suspect! But how? No-one could figure anything.

This is EXACTLY the reason to dig deeper into those dud sets.

Even shipper can be a problem.

Maybe so for sets 1-4, but not 5,6. I knew the business involved, the
2nd dealer, and was asked in to help de-mysterise, without success.
Both sets 5 and 6 were checked at installation.

Okay that is small step.

I think power spikes are not a problem, any consumer equipment has
sufficient filtering built in to protect itself. Especially stuff like
TVs and puters. Surge protectors have little effect by comparison. The
house was on a big estate, so any problems would have been shared all
round.

Localized surges can happen if the power is shared with other massive
items that inductively switch out and in rapidly. Pow!

power plugs?

wouldn't make any difference AFAICS.

That depends on specific chassis. Few crappiest chassis had one diode
instead of bridge rectifier. The neutral is the shared cold/hot
ground. Reversed outlet may be a problem.

We're talking low cost used sets, so no-one cared what make and model
they were. It was just screen size and decade of manufacture that
counted.

Doesn't matter. 24" is almost the bottom end but we still charge
decent money on those. FYI: N. Amcerican TV's is 25" and "worthy
doing" but to you it is 24". 20" & 19" is too cheap here, we don't
spend too much time on 13" it is disposeable.

It would have been helpful if you supplied some details such as the
TV
makes and models, as well as the results of any post mortem analysis.

I dont really have any more to give you. Second hand dealers dont
investigate things the way a manufacturer would. If the customer keeps
bringing stuff back, they dont serve em anymore. Thats it.

Then dealer is not doing the job, they must find out WHY and make the
customer happy this means they must drop these sets into your hands,
this means dealer chasing money which IHMO bit sleazy.

1. Major power glitches via the AC power.

6. EMF (Electro Magentic Field). Proximity to a large magnetic or
electric field such as the transformer on an X-ray machine.

This will make pix MOVE around like wild. I saw that when I rode on a
linear motor trolley lab demo, they had test equipments hooked up
using pc monitors. Wow, really cool to see the pix move around and
feel the hum of motor in sync with that at same time.

Bad neutral connection in the panel, causing the voltage to swing up?

The UK isnt wired like that, so we dont get that problem.

I'm still mysterised. Maybe news2020 was right after all

Well, I had seen one once, errant loose staple inside a late model
(citizen) flat CRT combo tv/vcr kept shutdown, the SMPS is smart
design and sensitive so there wasn't a blow up at all. Took that bit
off between the magnetic biased inductor pin and ground pan. TV
started working fine.

Regards, NT

Cheers,

Wizard

 

[Nigel]

The last time I had a serial equipment killer like that, it was due to a
faulty sub-station (in Leicester) that was kicking out 275v pretty much all
the time, instead of 240v.

It was only proved after the electricity company arranged for a voltage/time
measurement recorder to be fitted into the house for a few days.


"N. Thornton" <bigcat@meeow.co.uk> wrote in message
news:a7076635.0309010728.3d0f65b4@posting.google.com...
Hi. A true life conundrum for you.


A customer gets 4 used TVs from dealer B, one after the other. Every
one of them dies within a week, thats the reason for the replacements.
Customer A is pretty unhappy with dealer B, blaming their duff
products.

Customer A goes to dealer C, and tells story of woe. Customer wants a
TV, but is understandably afraid to buy. Dealer C offers to do 2
things:
1. investigate their house to search for any possible cause for this,
and if none is found,
2. to offer 3 month guarantees with any used set sold. Any fault on
the set, full refund.

So, the house survey reveals no cause. No cat peeing, no vase of
flowers on the TV, no damp problem, no TV falling off its stand, no
rugs to put on the TV vent grills, no sign of deranged inhabitants, no
diesel generator, no invertor, no spraying with water based aerosols,
nothing. So customer goes home with dealer C's guaranteed used TV.
Dealer C is full of confidence, both thinking that dealer A must have
been a badun.

But things are not as they seem. After 3 days a call comes in: the TV
doesn't work. Van dispatched with replacement TV, and the faulty one
is subject to thorough examination back at dealer C's premises. Again,
no external issues are found. No damp, no patch marks, no smell of cat
pee, no screws undone, no scratches from the TV being knocked about,
nothing.

With in a week, another call. TV number 6 is dead now. Feeling that
sinking feeling, the van is dispatched one last time. We have no
replacement TV in stock, we'll get yours done within 2 days.

Same examination, and again no cause found. Dealer C decides at this
point to refund the money, and advises customer to rent instead, from
their main competitor.


The only data I dont have is the failure modes for TVs 5 and 6. To
this day no-one knows why those 6 TVs died. What could have happened
in this tale of the Bermuda TVriangle?


Regards, NT

 

[Arthur Jernberg]

Our directive on the APEX units is to rethurn them to the vendor if under
warrenty or service contract besause they do not support their products with
service parts, diagrams, or technicial information: neither the teles or dvd
players.
"dave" <k8sjs@sbcglobal.net> wrote in message
news:JeR4b.17860$Ih1.6763231@newssrv26.news.prodigy.com...

I had read that apex did'nt plan on repair or replacement parts
for this unit...a buy and replace deal....I have one too but
not
used much.....still ok...but I will throw it away if anything
happens.....

 

[N. Thornton]

Hi


I hadn't planned to become quizmaster, but it seems I have Lets see
what bits I can fill in.

No models & brands?

No, they were assorted used 24" sets, various makes.

Uggh... I don't like this...!

Why is your job reported this without all the details, you gotta have
the paperwork with serial and models on them when they came in for
checks and estimate or warrenty repairs?

A dealer of cheap used sets isnt interested in all that. A bit of
paper stuck on them saying 'Joe tripler Ł30' was as far as paperwork
went. Its a very different scene to say a manufacturer. No-one would
be writing down serial numbers.

Re warranty returns it makes more sense to swap them. 'OK, sorry bout
that, it can happen occasionally. These are the Ł30 ones here, help
yourself.' Saves a lot of muck about, and keeps customers happy with
instant service. The return just goes on the supply pile, no rush.

But series of duds in a row is very suspicious and must be carefully
analyzed which means opening up the sets and take a look and note the
models. Frankly, I'm disappointed with this because we still have
nothing to go on so far.

6 assorted sets died, so I doubt the exact models make that much
diference. Tho I agree it would be nice to know, they might all share
a feature.

rare but happens, faulty equipment
hooked to that TV

Good point. But... I cant see any way a video could damage a TV.
There
are no other external connections on those old sets. Putting mains
up
the aerial socket would be harmless to the TV. The input capacitors
would just sit and smile.

Considered that? Intermittent house's open neutral wire especially
in
cheap sets that has hot ground throughout the chassis, so power went
through wrong paths through RF connector or video inputs.
But I don't know what system is like for western 230V.

The only connector on those old sets is the aerial plug. They use very
thick insulators in the way: nothing is ever going through there
except UHF. So basically this is impossible.

customer

Prime suspect! But how? No-one could figure anything.

This is EXACTLY the reason to dig deeper into those dud sets.

I agree, from our point of view. But this was a business, they just
moved on. They could have fixed several sets in the time it would have
taken to get to the bottom of it.

And there's always a small percentage of nutty customers anyway, who
buy stuff and do weird things with it, then complain that it doesn't
work. Getting rid of them is the only sensible option.

power plugs?

wouldn't make any difference AFAICS.

That depends on specific chassis. Few crappiest chassis had one
diode
instead of bridge rectifier. The neutral is the shared cold/hot
ground. Reversed outlet may be a problem.

I can't see how it would make any difference. I assume all those sets
were live chassis, and in at least most cases bridge rectifier from
mains to chassis. Whether BR or diode... perhaps you can explain a
failure mechanism.

We're talking low cost used sets, so no-one cared what make and
model
they were. It was just screen size and decade of manufacture that
counted.

Doesn't matter. 24" is almost the bottom end but we still charge
decent money on those. FYI: N. Amcerican TV's is 25" and "worthy
doing" but to you it is 24". 20" & 19" is too cheap here, we don't
spend too much time on 13" it is disposeable.

Yup. It was the other way round there, with the big old 24"ers being
cheaper cos they were such elepants. People mainly wanted 19"s. We
have much smaller houses here on the whole.

I dont really have any more to give you. Second hand dealers dont
investigate things the way a manufacturer would. If the customer
keeps
bringing stuff back, they dont serve em anymore. Thats it.

Then dealer is not doing the job, they must find out WHY and make the
customer happy this means they must drop these sets into your hands,
this means dealer chasing money which IHMO bit sleazy.

The dealer is just there to make a living, its his job. The dealer
went out of his way to create a happy customer, but to no avail. I've
never come across a second hand equipment dealer who would go to the
lengths you suggest. They'd soon be out of business.

Perhaps they had a loose neutral connection somewhere so that when a
particular appliance came on the line voltage rose.

The UK isn't wired like that, no V_rise is possible that way. Our
supply is 240v, not 120-0-120. Loads can only cause V_drops.

eternity. Here is one: Did the customer have the bad habit of
switching the
set off and on rapidly? A lot of TVsets, even new ones, will not
survive
this treatment for long.

Good point, one of the kids might have. I'll ask you for a failure
mechanism tho, as I cant think how it would fry anything.

While attempting to allign a friends TV some years ago I touched the
antenna
to earth ground and cooked the tuner resulting in no picture or
sound.
This wrote off the TV.

One possible reason that these TVs failed is that there may have been
a path
to ground through a cable Connection.

Normally the antenna connection is very heavily insulated from the
chassis on both poles. You could put a kV on there and nothing should
happen. I'm surprised yours died. It would be very different if you
had baseband connectors, but with UHF aerial only, the thing should be
virtually bullet proof.

The last time I had a serial equipment killer like that, it was due
to a
faulty sub-station (in Leicester) that was kicking out 275v pretty
much all
the time, instead of 240v.

It was only proved after the electricity company arranged for a
voltage/time
measurement recorder to be fitted into the house for a few days.

ahhhh! Presumably tho much of the estate would have had the same
problem, if that was the cause.

In fact, on second thoughts, I'm not so sure. Junkers routinely had
their PSUs set to the 220v setting when the tube was crap, and
sometimes 200v to get the picture watchable. That would up the V
throughout the set, heater, EHT, everything, yet they survived OK. 240
on 200v is +20% too high, 275 on 240 is only 14.6%. So I'm not
convinced yet that would account for 6 rapidly dead sets, but
possibly.



This all happened years ago, and I still dont have an explanation I'm
really convinced by. Its odd.


Regards, NT

 

[Sam Goldwasser]

"Leonard Caillouet" <lcailloNOSPAM@devoynet.com> writes:

"Louie" <beavisnbutthead@softhome.net> wrote in message
news:gdR4b.326269$YN5.224769@sccrnsc01...

i have a small 12volt tv that is based on the KA2915 chip. the tv has an
RF input but no A/V input. i want to know if its possible to tap in
somewhere with a composite signal and bypass the RF stuff.

Of course it is possible, but not likely to be practical nor safe to do. If
you have to ask this question you are likely not going to possess the skills
and knowledge to manage this kind of interface without problems. Save some
headaches and just buy one with composite inputs. They are cheap.

If it's only 12 V input, it is probably safe from a shock point of view.

How feasible it is may be another matter. Someone will have to get
the schematic and determine if the output of the tuner module is
simple composite video and audio. But I agree, this is probably not
something you could do unless it is just a matter of using a feature that
was simply not implemented in the particular model.

--- sam | Sci.Electronics.Repair FAQ Home Page: http://www.repairfaq.org/
Repair | Main Table of Contents: http://www.repairfaq.org/REPAIR/
+Lasers | Sam's Laser FAQ: http://www.repairfaq.org/sam/lasersam.htm
| Mirror Site Info: http://www.repairfaq.org/REPAIR/F_mirror.html

Important: The email address in this message header may no longer work. To
contact me, please use the Feedback Form at repairfaq.org. Thanks.

 

[Bill]

"Mark D. Zacharias" <mzacharias@nospam.earthlink.net> wrote in message news:<J9O4b.4967$tw6.239@newsread4.news.pas.earthlink.net>...

They can't put in a jumper for the backup - it would short the power supply
to the timer IC. You're looking at it wrong. There would usually be a backup
capacitor on the front circuit board near the display tube.

Mark Z.


"john" <va3mmTAKEOUTTHIS@niagara.com> wrote in message
news:newscache$06cjkh$cs7$1@newsfeed.niagara.com...
Its inside of the audio module which is soldered to the pcb
located near the tuner it runs parallel to the rear of the set.
Pull the module then jump pins 4 to 14 and 5 to 15 on the pcb.

kip



--
"Watch the return E-Mail addy its false"
"Bill" <elect21st@aol.com> wrote in message
news:8fb59540.0308311512.1606582e@posting.google.com...
I have a Sony KV32XBR10 with sound problems. I'm trying to bypass
SBX1593 which is NLA, but NOBODY seems to know where it is exactly on
this chassis !! Is it similar to SBX1637 which I replaced many times ?
Every time I go back to this set and look around with lights and
magnifier but still can't find it ! I would like to hear from someone
who actually did the bypass and knows for sure. Thanks !



It appears that most of my previous message got deleted somehow.

This is mainly for Kip.... there is a module that fits your
description in the back of the set. I opened both covers and found a
lot of SMD components along with an 8 pin IC, which looks like an
eeprom. Maybe what the other guys are saying is true ? Did you
bypass this SBX1593 on this particular model ? Thanks

Bill

 

[john]

Yes thats the module..4 to 14 and 5 to 15 with module out.
kip



--
"Watch the return E-Mail addy its false"
"Bill" <elect21st@aol.com> wrote in message
news:8fb59540.0309020329.68f8fce8@posting.google.com...

"Mark D. Zacharias" <mzacharias@nospam.earthlink.net> wrote in message
news:<J9O4b.4967$tw6.239@newsread4.news.pas.earthlink.net>...
They can't put in a jumper for the backup - it would short the power
supply
to the timer IC. You're looking at it wrong. There would usually be a
backup
capacitor on the front circuit board near the display tube.

Mark Z.


"john" <va3mmTAKEOUTTHIS@niagara.com> wrote in message
news:newscache$06cjkh$cs7$1@newsfeed.niagara.com...
Its inside of the audio module which is soldered to the pcb
located near the tuner it runs parallel to the rear of the set.
Pull the module then jump pins 4 to 14 and 5 to 15 on the pcb.

kip



--
"Watch the return E-Mail addy its false"
"Bill" <elect21st@aol.com> wrote in message
news:8fb59540.0308311512.1606582e@posting.google.com...
I have a Sony KV32XBR10 with sound problems. I'm trying to bypass
SBX1593 which is NLA, but NOBODY seems to know where it is exactly
on
this chassis !! Is it similar to SBX1637 which I replaced many times
?
Every time I go back to this set and look around with lights and
magnifier but still can't find it ! I would like to hear from
someone
who actually did the bypass and knows for sure. Thanks !



It appears that most of my previous message got deleted somehow.
This is mainly for Kip.... there is a module that fits your
description in the back of the set. I opened both covers and found a
lot of SMD components along with an 8 pin IC, which looks like an
eeprom. Maybe what the other guys are saying is true ? Did you
bypass this SBX1593 on this particular model ? Thanks

Bill

 

[john]

The module you are looking for is the audio / sap module
there are 2 modules parallel to the rear of the set .
Its the one closest to the front inside, there are many
IC,s in the module and if you have the correct one open
it up you should see a large IC which looks like a
large sbx1637 there will be a burn mark in the middle.

kip

--
"Watch the return E-Mail addy its false"
"john" <va3mmTAKEOUTTHIS@niagara.com> wrote in message
news:newscache$yi3lkh$sbb$1@newsfeed.niagara.com...

Yes thats the module..4 to 14 and 5 to 15 with module out.
kip



--
"Watch the return E-Mail addy its false"
"Bill" <elect21st@aol.com> wrote in message
news:8fb59540.0309020329.68f8fce8@posting.google.com...
"Mark D. Zacharias" <mzacharias@nospam.earthlink.net> wrote in message
news:<J9O4b.4967$tw6.239@newsread4.news.pas.earthlink.net>...
They can't put in a jumper for the backup - it would short the power
supply
to the timer IC. You're looking at it wrong. There would usually be a
backup
capacitor on the front circuit board near the display tube.

Mark Z.


"john" <va3mmTAKEOUTTHIS@niagara.com> wrote in message
news:newscache$06cjkh$cs7$1@newsfeed.niagara.com...
Its inside of the audio module which is soldered to the pcb
located near the tuner it runs parallel to the rear of the set.
Pull the module then jump pins 4 to 14 and 5 to 15 on the pcb.

kip



--
"Watch the return E-Mail addy its false"
"Bill" <elect21st@aol.com> wrote in message
news:8fb59540.0308311512.1606582e@posting.google.com...
I have a Sony KV32XBR10 with sound problems. I'm trying to bypass
SBX1593 which is NLA, but NOBODY seems to know where it is exactly
on
this chassis !! Is it similar to SBX1637 which I replaced many
times
?
Every time I go back to this set and look around with lights and
magnifier but still can't find it ! I would like to hear from
someone
who actually did the bypass and knows for sure. Thanks !



It appears that most of my previous message got deleted somehow.
This is mainly for Kip.... there is a module that fits your
description in the back of the set. I opened both covers and found a
lot of SMD components along with an 8 pin IC, which looks like an
eeprom. Maybe what the other guys are saying is true ? Did you
bypass this SBX1593 on this particular model ? Thanks

Bill

 

[WbSearch]

Mark, I agree. But it is in the position of C315 on the board which is what
the manual calls a battery and the parts people call the memory cap. I am
confused.

 

[Nigel]

"N. Thornton" <bigcat@meeow.co.uk> wrote in message
news:a7076635.0309020255.6529f99d@posting.google.com...

The last time I had a serial equipment killer like that, it was due
to a
faulty sub-station (in Leicester) that was kicking out 275v pretty
much all
the time, instead of 240v.

It was only proved after the electricity company arranged for a
voltage/time
measurement recorder to be fitted into the house for a few days.

ahhhh! Presumably tho much of the estate would have had the same
problem, if that was the cause.

--------------------------------------------------------------------

No, bizarrely enough, the problem was isolated to one street in one suburb
and no other equipment owned by our customer expired in suspicious
circumstances. To the best of our knowledge at the time, none of the
neighbours experienced problems with any equipment.

 

[Dave VanHorn]

if i had to guess, low voltage.

 

[Tony Williams]

In article <SaqdncbMToaQMMmiXTWJiQ@comcast.com>,
Dave VanHorn <dvanhorn@cedar.net> wrote:

if i had to guess, low voltage.

We have experienced a tv failure during an extended
browndown (and recovery). The Telefunken tv that
replaced it had a built in latching relay on the mains.

--
Tony Williams.

 

[Walter Craig]

Variac is a bit expensive. I have heard it can be done with a Triac. Can any
one help with info.
Walter.
"ajb" <ajb@sphynxstopdemonstopcostopuk> wrote in message
news:e4c7lv0m2fd9uuhgejbo4rn5lnjb3653sq@4ax.com...

On Mon, 1 Sep 2003 21:10:55 +0100, "Walter Craig"
walter@craig8607.freeserve.co.uk> wrote:

Can I regulate the 240v input of a mains transformer in order to set the
output to 7/14v of a 18v-40amp battery charger.
Without using wirewound resistance its wastfull and warm.
Thanks.
Cutty.


You could use a Variac (variable voltage transformer) on the input,
though unless you have one handy which would handle several hundred
watts (or _never_ turn it up too much on load!) it might be a bit
expensive. But surplus items do sometimes turn up cheap.....

And you'd lose some of the regulation and 'stiffness' of your charger
anyway, whatever method you used, though that might not matter.

AJB
--

Un-stop the address to reply, please.

If the 'self' is an illusion, who is being fooled?

 

[Jim Thompson]

On Tue, 02 Sep 2003 06:27:00 GMT, "James Sweet"
<jamessweet@hotmail.com> wrote:

Perhaps they had a loose neutral connection somewhere so that when a
particular appliance came on the line voltage rose.

[snip]

A very good possibility.

In 1993, while I was working in Europe, our oldest daughter was
house-sitting for us.

When we returned she told us that, when using our shower, it sometimes
felt like an electrical shock.

A little metering revealed 15VAC between the shower head and the
drain.

In Arizona "ground" is established by bonding water pipes to incoming
neutral (but not the sewer piping).

I also noticed that some lights would brighten and some would dim when
the A/C came on.

A call to the power company got us an instant temporary neutral while
they dug up the underground feed.

In our newest house I personally added local bonding between the
shower piping and the metal part of the drain before the floors were
poured.

...Jim Thompson
--
| James E.Thompson, P.E. | mens |
| Analog Innovations, Inc. | et |
| Analog/Mixed-Signal ASIC's and Discrete Systems | manus |
| Phoenix, Arizona Voice480)460-2350 | |
| E-mail Address at Website Fax480)460-2142 | Brass Rat |
| http://www.analog-innovations.com | 1962 |

I love to cook with wine. Sometimes I even put it in the food.

 

[Jeremy]

The one I picked up (BK Precision 881) claims to output @ 15mV and
came out June 30, 2003, so it's fairly new. I'm wondering if it's a
bad tester because it can't seem to read ESR correctly in-circuit.

Jeremy

On Tue, 2 Sep 2003 07:57:04 -0400, "Jerry G." <jerryg@total.net>
wrote:

Many of the older ESR meters used too high a voltage with too high a
source resistance, and are triggering or reading other components that
are connected to the one under test. This is why you have to remove the
part to properly test it. The new meters use typically about 50 to 100
mV with a very low source resistance. At about 250 to 300 mV, they can
start to trigger other devices (especially some semiconductors), and
these would be included in the measurements.

If you have a shorted or very leaky cap, the ESR meter can be fooled,
and thus give a low reading. ESR meters are good for when caps go
opened, which is the most common type of failure with them. In the case
of the older types of ESR meters used on modern circuit boards, the
meter will read the other components wired in.

A descent ESR meter is very low in cost these days, in relation to the
savings you will get. I would suggest in investing in one if you plan on
testing a lot of caps. There are a number of good ones on the market
today. The Bob Parker one is one of the best rated ones I have been
reading and hearing about.


You can visit Bob Parker's web page:
http://www.ozemail.com.au/~bobpar/