Toshiba TV29C90 problem; Image fades to black...

[Tux]

Hi Leonard

I have e-mailed Yamaha through the customer service section on their EU site
MANY times but received no reply. The dealer I have to deal with is
Videoacustica in Portugal. When the unit first developed the fault it was
still under warranty but Videoacustica said that they would not repair it
under warranty as I did not purchase it from them. I purchased the unit in
Germany but as per EU trade law the warranty should be valid in Portugal
aswell. Not so ?

Anyway....very dissapointed with Yamaha for not replying to my e-mails and I
don't know who else to call in Europe regarding this matter. Maybe someone
here can help ? !

Cheers

Who did you send it to? Yamaha would have likely take some action by now
if there was that kind of delay for parts. You need to call Yamaha
customer service. Where is your dealer in all of this?

Leonard


Hi

I have the exact same problem with a Yamaha RX-V1400. Unit shuts-off
after a few minutes even with no sources or ouputs connected. I did post
about it here awhile ago but received no reply, so in the meantime I sent
it to the local Yamaha Service and it has been there for 4 months. They
now say the EPROM has lost configuration and they are waiting for a new
one. I suspect they have stuffed it up as I don't think the EPROM could
have been the cause of this problem. If you or anyone finds the cause of
cause please let me know. And IF mine ever gets repaired I will let you
know.

Regards

Ampless :-(


"jw51" <western@webace.com.au> wrote in message
news:1141539005.552320.191660@i39g2000cwa.googlegroups.com...
No power on function, started becoming difficult to turn on over a
couple of days.

Checked speakers(Bose lifestyle) could find no problem.

Am trying to source a service manual for it.

Any ideas?

 

[Ross Herbert]

On Fri, 10 Mar 2006 08:19:04 -0000, "Tux" <tux@netmadeira.com> wrote:

Hi Leonard

I have e-mailed Yamaha through the customer service section on their EU site
MANY times but received no reply. The dealer I have to deal with is
Videoacustica in Portugal. When the unit first developed the fault it was
still under warranty but Videoacustica said that they would not repair it
under warranty as I did not purchase it from them. I purchased the unit in
Germany but as per EU trade law the warranty should be valid in Portugal
aswell. Not so ?

Anyway....very dissapointed with Yamaha for not replying to my e-mails and I
don't know who else to call in Europe regarding this matter. Maybe someone
here can help ? !

Cheers

Is their a Consumer Protection or Fair Trading body in your local

government? A complaint about the lack of reasonable service might get
someone off their backside. Perhaps a warning that you are
contemplating such an action might get the repair accomplished.

 

[Sam Goldwasser]

Smitty Two <prestwhich@earthlink.net> writes:

In article <hup1121r3itefphn1t846p67jlal4bt0rh@4ax.com>,
Ross Herbert <rherber1@bigpond.net.au> wrote:

On 9 Mar 2006 15:07:37 -0800, runderwo@mail.win.org wrote:

I got a service diagram from Lab-Volt after much consternation. Looks
like the holder is supposed to be like that, when the holder screws in
it both tightens up the "link" to the fuse as well as completes the
connection. So the holder may not be broken, I'll just see if it blows
another fuse before proceeding. Thanks for the helpful replies.


You are a worry... this is the first time you have even mentioned that
the unit is "blowing fuses". Your previous posts inferred that the
problem was with continuity related to this fuse, but this new
information puts a whole new complexion on things. The very fact that
the fuse is blowing infers there is nothing wrong with the fuse holder
or the fuse. Assuming that you are using a properly rated delay fuse
(slo-blo, or time delay fuse usually with a 'T' marking), and it is
still 'blowing', then the fuse and holder are fine. The most likely
problem is that there is some component following the fuse which is
overloading it and causing it to do its intended job.

Have you even opened the case to see if there is any obvious sign of a
short circuit anywhere? Perhaps I shouldn't ask that if your attempt
to repair the unit up till now is an indication of your knowledge.

The OP's claims to the contrary, it seems to me that he doesn't know a
fuse from a fuse holder. Fine, ignorance is OK, and if he's a novice, I
have no problem with that. But, his complete inability to see what he
sees and communicate it clearly is exceptionally frustrating. One
picture link would help us help him.

It's of more concern that if he doesn't know a fuse from a fuse holder,
he may not know the difference between a live wire and ground and may end
up dead.

--- sam | Sci.Electronics.Repair FAQ: 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 Sites: http://www.repairfaq.org/REPAIR/F_mirror.html

Important: Anything sent to the email address in the message header above is
ignored unless my full name AND either lasers or electronics is included in the
subject line. Or, you can contact me via the Feedback Form in the FAQs.

 

[Leonard Caillouet]

No experience with Yamaha outside the US. Here they are very customer
oriented. They will not, however, support products from another country.

I would go back to the vendor in germany.

Leonard

"Tux" <tux@netmadeira.com> wrote in message
news:44113682$0$15573$a729d347@news.telepac.pt...

Hi Leonard

I have e-mailed Yamaha through the customer service section on their EU
site MANY times but received no reply. The dealer I have to deal with is
Videoacustica in Portugal. When the unit first developed the fault it was
still under warranty but Videoacustica said that they would not repair it
under warranty as I did not purchase it from them. I purchased the unit in
Germany but as per EU trade law the warranty should be valid in Portugal
aswell. Not so ?

Anyway....very dissapointed with Yamaha for not replying to my e-mails and
I don't know who else to call in Europe regarding this matter. Maybe
someone here can help ? !

Cheers

Who did you send it to? Yamaha would have likely take some action by now
if there was that kind of delay for parts. You need to call Yamaha
customer service. Where is your dealer in all of this?

Leonard


Hi

I have the exact same problem with a Yamaha RX-V1400. Unit shuts-off
after a few minutes even with no sources or ouputs connected. I did post
about it here awhile ago but received no reply, so in the meantime I
sent it to the local Yamaha Service and it has been there for 4 months.
They now say the EPROM has lost configuration and they are waiting for a
new one. I suspect they have stuffed it up as I don't think the EPROM
could have been the cause of this problem. If you or anyone finds the
cause of cause please let me know. And IF mine ever gets repaired I will
let you know.

Regards

Ampless :-(


"jw51" <western@webace.com.au> wrote in message
news:1141539005.552320.191660@i39g2000cwa.googlegroups.com...
No power on function, started becoming difficult to turn on over a
couple of days.

Checked speakers(Bose lifestyle) could find no problem.

Am trying to source a service manual for it.

Any ideas?

 

[Kirk S.]

"Bill S." <nospam@onme.net> wrote in message
news:MPG.1e78ef0e950692898969d@news-server.woh.rr.com...

In article <Gk7Pf.13246$ty4.7761@tornado.rdc-kc.rr.com>,
crayzkirk@yahoo.com says...
I've got a Magnavox RH8524AK08 projection TV that went dead. I bought a
set
of boards from an RH8520 from a guy on eBay. The power supply board
indicated in my service manual is the same for both sets (APW007). The
flyback is totally different on the set that I bought; my original has a
tube that comes out at an angle that the HV line slips into and a nut
tightens down. Since the set I bought came with the HV line and
splitter, I
replaced the associated parts as well. The TV now comes on.

It's unusual to find one of those relics that still works. We used to
call them "gourmet flybacks from Orville Reddenbacher", you know - not
a one left unpopped ;-) A slight exaggeration, no doubt, but a *lot*
of them blew up. I guess if you have one that survived this long, no
reason not to keep using it.

Unfortunately, the dead flyback is one of the angle HV connector types.
Found a sticker in the bottom of the set: 3620030005. Have found similar
ones for 3620030006/7. The newer board had the 352140-1 flyback on it.
Guess I can just repair it if (when) it blows.

Another common problem about that vintage was green circuit boards
that used square pins shoved through the board for feed-throughs
instead of plated-through holes. This attempt at cost cutting was a
notorious source of intermittant connections. Some were so bad that
they required repair right out of the box before they could even be
sold.

Yep, the convergence board required resoldering of these square pins. Had a
blue ghost that would appear and disappear when the set warmed up. The old
p/s board is green with those nasty square pins. I reflowed some fresh on
the convergence board and that took care of the problem.

Is this going to cause a problem?

Aside from the questionable reliability of certain parts already
mentioned, I don't see a problem. There were minor variations for
special versions like the JBL sound system, but basically they were
intended to be compatible. As you have discovered, the HV lead is
different, so just use the one that came with it.

Would it help to replace the electrolytic caps on the deflection and power
supply boards?

Given the age of the set, is it likely the power supply was changed
at some point?

Fair chance. We used to carry a set of spare boards in the service
truck for elusive problems. Sometimes easier to swap in the home and
rebuild back at the shop where presumably you have better lighting,
more tools, parts, and equipment.

Also, where can I get replacement crt seal kits so I can change the
coolant?

The O-rings between the lens and the cooling chamber are quite durable
and usually reusable. I have not often needed the gasket between the
CRT and cooling chamber except on the rare occasion of replacing a
tube. Philips didn't list these parts separately in the manuals, but
shows one each as parts of the 171677-3 kit. I used to have the
individual numbers written down somewhere but can't find them anymore.

What sort of sealer/lubricant should I use on the o-rings? Or, should I
just clean out the crud the best I can, replace the coolant (with the set
angled so the crt in question is level) and see what sort of improvement I
get?
Thanks again for the advice. The cabinet on this thing is so nice that I'm
having a hard time getting rid of it.

Kirk S.

 

[Sam Goldwasser]

Bill Jeffrey <wjeffreyAT@alum.DOTmit.edu> writes:

Sam Goldwasser wrote:

This is certainly true. I think the cool storage is fine but it should
also be dry.

Sam -

Some of us don't have the advantage of a dry climate. Here in Arizona
things are usually quite dry, for example. But I have half of my
DVDs stored on the coast in Maine, where it is quite humid at least 9
months of the year. I assume it would be helpful to put my DVDs in
some sort of waterproof box - even a big Tupperware box - and toss in
a couple of the "Do Not Eat" silica gel packets that come in bags of
rice crackers and other crispy foods?

Sure. I'm not sure how much it matters but the metallic film is very
thin and may not be totally protected if the overcoat on the label side
has pinholes, which are quite possible.

--- sam | Sci.Electronics.Repair FAQ: 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 Sites: http://www.repairfaq.org/REPAIR/F_mirror.html

Important: Anything sent to the email address in the message header above is
ignored unless my full name AND either lasers or electronics is included in the
subject line. Or, you can contact me via the Feedback Form in the FAQs.

 

[Sam Goldwasser]

Jim Yanik <jyanik@abuse.gov> writes:

Sam Goldwasser <sam@saul.cis.upenn.edu> wrote in
news:6wzmjo306e.fsf@saul.cis.upenn.edu:

Jim Yanik <jyanik@abuse.gov> writes:

"Ancient_Hacker" <grg2@comcast.net> wrote in
news:1142617094.382451.289320@j52g2000cwj.googlegroups.com:

Oh, there's also a big voltage divider resistor (the white ceramic
thing) Any moisture, dust, or leakage there and you tend to get
unstable HV.



The HV thick-film resistor network(TEK-made) has the HV feedback for
regulation on one side,and the CRT focus divider on the other. Either
one can go out-of-tolerance,and the metal pins can crack and be
intermittent.I've never been successful in resoldering them,either.

I do not think this part would be the cause of his intensity
modulation.

Followup: The frequency of the chopped line does NOT correlate with
line frequency.

Perhaps HV oscillator freq?

I don't think so. It's order of a few hundred Hz and not constant.

And I should note that at low intensity, it is worst going full off.
With the intensity turned up, it's not visible. There is minimal
if any geometric distortion of the trace (outside of the focus
problem, which doesn't always appear) so I doubt any LV power supplies
are involved that also feed the amps.

Then you're down to decoupling caps.

It's almost as if the Z input has some oscillation on it. When I
first noticed, I thought maybe the chopped blanking was misbehaving,
but this occurs on all vertical modes.

A thought occurs to me;there's a 1uf/150V(IIRC) electrolytic on the wiper
of the CRT grid bias pot,to ground;that could be going bad.

I'll check that.

It's also related to warmup. At power-on, there is no problem. It
takes a of couple minutes to show up. The fan is running.

And even then, the severity varies randomly.

So, what could affect the Z modulation AND sometimes focus, but not
geometry?

If it was the HV divider I guess a parts unit is the only source for a
replacement?

Yes,it was a TEK-made part,from their defunct hybrid/ICO in-house plant.
Removing a good one from a motherboard without damaging it is not an easy
task

Now it really doesn't like even normal intensity.

But the geometry (beam stiffness, etc.) is not affected. So, I'm
leaning toward a problem in the grid circuit, not the HV itself.

Does anyone know of a free source for decent quality schematics? I have
several complete manuals downloaded from various places but the resolution
of the schematics tends to be terrible and only marginally useful.

--- sam | Sci.Electronics.Repair FAQ: 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 Sites: http://www.repairfaq.org/REPAIR/F_mirror.html

Important: Anything sent to the email address in the message header above is
ignored unless my full name AND either lasers or electronics is included in the
subject line. Or, you can contact me via the Feedback Form in the FAQs.

 

[Arfa Daily]

"OldSchool" <barrettgr@comcast.net> wrote in message
news:1142700697.668093.5620@j33g2000cwa.googlegroups.com...

I use my old KAA-5700 to drive some other speakers off my Yamaha
RX-V995. This was working but recently it stopped. How do test if it is
the Output of my Yamaha or the Kenwood that is failed?

Try the output from the Yammy into a different input on the Kenwood - "
tuner " or " tape in " for instance.

Arfa

 

[Arfa Daily]

"janek77" <alkaprim@hotmail.com> wrote in message
news:sNUSf.11933$ng.680103@news20.bellglobal.com...

Hi, that damn things overloads?
When powered up as is the output voltages are ~40% too low.
Then when I disconnect ie 12V or 55V load everything seems to run fine, ie
voltages are right and adjustment works fine.
The only difference , it runs twice too fast (by checking waveform 1).
Could it be the transformer?(maybe primary winding has short?)
Here's the schematic:
http://img.photobucket.com/albums/v338/gamow/PS.gif




First place I'd be looking, is at the electrolytics. Either run an ESR meter

across them all, or look at each rail with another 'scope. Chances are,
you'll find one with shedload of hash on it. Particularly suspect any that
are near anything else that gets hot.

Arfa

 

[OldSchool]

That works. I pushed it through the Phono and it works but sounds like
crap. Sounds like the Aux on the kenwood is out. Any quick fixes?

 

[OldSchool]

They all work but sound like crap. If I just run my Kenwood amp and
tuner through the system (without any link to the yama) it sounds fine.
Sounds like my 25+ year old amp finally boosted it's last signal.

 

[hd_74al]

Mike: The AIRCO 250 AC/DC welder is single phase 220v, nothing real
special on this part of it. After I posted this I took the Bridge
rectifier out of the welder to test the power diode and the SCR's. This
welder has two SCR's (hockey puck style) mounted in the aluminum heat
sink.

Here's were I need some help. I tested the power diode with a
multimeter and only got a reading one way. That should mean that the
diode is okay?

To test the SCR's I used a 12v car battery, a 12 volt light and made
two connections from the positive lead; one with a resister (1k 1/2W)
to trigger the gate (white lead) and the other with a resister (100,
2w) to the device (red lead). The negative lead was to the metal case
of the device. With the connections intact I took the one lead (white)
and was able to get the lamp to light but not stay on. It should stay
on with a good SCR, correct?

The other SCR did not light at all. Am I on the right track?

Mike Berger Wrote:

It doesn't indicate a dead short. A 250 amp bumblebee welder draws
a hefty initial current. What kind of circuit do you have it plugged
into?


hd_74al wrote:
I need some help from a person that knows electrical problems. I have
a
used welder that I am refurbishing. I have made a repair to the
interface board that had a blown capacitor. When I turned that welder
on it seemed that everything was okay with the fix so I am testing
the
weld capabilities. As I don't have it set up for the tig yet, I am
just
testing the "arc" functions. When I selected AC and used a 7018 3/32"
rod I was able to run a bead. When I selected DC (straight polarity)
or
DC (reverse polarity) and turned the welder on it flipped the circuit
breaker. The question(s) that I have:
1) Is this a dead short in the rectifier bridge? diode? If so how can
I
check the fault?
2) Can can check to see if the high frequency works using the "stick"
function?

Thanks for any help.

Al

--
hd_74al

 

[Adam Funk]

On 2006-03-18, Bill Jeffrey <wjeffreyAT@alum.DOTmit.edu> wrote:

Adam -

I would think that a CD label would be a GOOD thing, as long as you
don't pull it off (and why would you?). It would be a barrier against
the inadvertent scratches that happen during handling. Yes? No? It
would also tend to keep ambient light out of the disk - or at least the
side that is normally stored upward, facing the light.

I've been under the impression that the adhesives damage the coating.
(I could be wrong.)

 

[Sam Goldwasser]

Adam Funk <a24061@yahoo.com> writes:

On 2006-03-18, Bill Jeffrey <wjeffreyAT@alum.DOTmit.edu> wrote:
Adam -

I would think that a CD label would be a GOOD thing, as long as you
don't pull it off (and why would you?). It would be a barrier against
the inadvertent scratches that happen during handling. Yes? No? It
would also tend to keep ambient light out of the disk - or at least the
side that is normally stored upward, facing the light.

I've been under the impression that the adhesives damage the coating.
(I could be wrong.)

It's possible. Some solvents will make the coating literally peel off on
its own.

--- sam | Sci.Electronics.Repair FAQ: 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 Sites: http://www.repairfaq.org/REPAIR/F_mirror.html

Important: Anything sent to the email address in the message header above is
ignored unless my full name AND either lasers or electronics is included in the
subject line. Or, you can contact me via the Feedback Form in the FAQs.

 

[spudnuty]

I would also be interested in a solution to this problem. I have a
Toshiba laptop in my "to be repaired pile" and the same thing has
happened to the LCD cable. It was glued to the LCD glass and the glue
has aged and become brittle so that the connection is completely off.
Richard

n cook wrote:

Ancient_Hacker <grg2@comcast.net> wrote in message
news:1142598154.121374.53040@i40g2000cwc.googlegroups.com...
Hi, I have a small LCD display where the edge has a 60-track ribbon
cable going to the motherboard. The cable is clear plastic with very
thin carbon tracks. The end going to the PC board has gone
intermittent, so I pulled it off. Apparently it was glued on with some
gray goop.

The carbon tracks on the end of the cable have mostly pulled off the
plastic. I could cut off the bad end as there's about 1/4 inch of
slack in the cable BUT:

(1) There's some beige painted-on insulation over the carbon. It
comes off with acetone, but so do the carbon tracks! How do I get the
beige insulation off without hurting the delicate carbon underneath?

(2) What do I use to glue the cable back on? Or should I fashion a
clamp?


Help!


How are the conductors of the ribbon connected to the conductive lands on
the LCD glass ?

--
Diverse Devices, Southampton, England
electronic hints and repair briefs , schematics/manuals list on
http://home.graffiti.net/diverse:graffiti.net/

 

Typo it's 100k not 100: sorry.

Also anyone think these things are still good? I've had them for like
10 years and they where at a local hospital for like 10 more.

Thanks,
Dan.

 

[Arfa Daily]

"OldSchool" <barrettgr@comcast.net> wrote in message
news:1142712001.625572.126810@i40g2000cwc.googlegroups.com...

They all work but sound like crap. If I just run my Kenwood amp and
tuner through the system (without any link to the yama) it sounds fine.
Sounds like my 25+ year old amp finally boosted it's last signal.

Are you saying that all of the other inputs BAR the " Aux " work ok when

driven by the Yammy, but sound poor ? That is an odd state of affairs,
indeed. Whilst it will sound crap if you run a line level output from the
Yammy into the Kenwood's phono inputs, due to the fact that a line level
signal is about 100 times what the phono input is expecting, the other
inputs should work just fine. Tuner, CD, Tape In, and Aux, should all have
similar sensitivities, and usually, impedances. Does your Kenwood have "
Pre Out - Main In " RCA jacks on the back, linked by patch pins ? If so, try
the Yammy's line out, into the " Main In " Jacks.

Please clarify exactly what the situation is regarding using the other
inputs on the Kenwood. I might then be able to get a better idea of what to
suggest you try next.

Arfa

 

[Neil J. Harris]

Hi,
Have you tried Grandata, http://www.grandata.co.uk , they list them at
Ł1.50 + Ł1.00 p&p +VAT.

In message <dv9u5m$1po$1@mklab.ph.rhul.ac.uk>,
UHAP023@alpha1.rhbnc.ac.uk writes

Dear All,
Can anybody suggest a reasonably priced (less than ?15) source
of 1 or 2-off TDA1024 chip. It is a now obsolete thermostat
controller chip which drives a triac.

--
Neil J. Harris

 

[Arfa Daily]

<dasbrow@gmail.com> wrote in message
news:1142724620.357852.134910@u72g2000cwu.googlegroups.com...

Typo it's 100k not 100: sorry.

Also anyone think these things are still good? I've had them for like
10 years and they where at a local hospital for like 10 more.

Thanks,
Dan.

All the same thing - makes no odds. The " K " usually refers to the

dielectric type I seem to recall. The important bit is the " 100 ". Caps
below 1uF and above 1000pF, are usually marked in nanofarads ( 1000's of
picofarads ) so 100 would normally mean 100nF or 0.1uF. However, when caps
of this sort of value are marked by coloured stripes, then they are usually
in picofarads, so a 100nF cap will be brown black yellow, which equates to
100,000 picofarads, so even if the letter " K " is part of the value, this
still makes the marking read 100,000, which is the same as it would be
marked if it was striped _ if you see what I mean !!

As far as the caps still being ok goes, the answer to this will be 99.9%
yes. Polyester or similar dielectric caps, do not deteriorate. However, the
wise man, would run a capacitance meter over them first, just to be sure ...

Arfa

 

On 18 Mar 2006 12:40:11 -0500, Sam Goldwasser <sam@saul.cis.upenn.edu>
wrote:

Jim Yanik <jyanik@abuse.gov> writes:

Sam Goldwasser <sam@saul.cis.upenn.edu> wrote in
news:6wzmjo306e.fsf@saul.cis.upenn.edu:

Jim Yanik <jyanik@abuse.gov> writes:

"Ancient_Hacker" <grg2@comcast.net> wrote in
news:1142617094.382451.289320@j52g2000cwj.googlegroups.com:

Oh, there's also a big voltage divider resistor (the white ceramic
thing) Any moisture, dust, or leakage there and you tend to get
unstable HV.



The HV thick-film resistor network(TEK-made) has the HV feedback for
regulation on one side,and the CRT focus divider on the other. Either
one can go out-of-tolerance,and the metal pins can crack and be
intermittent.I've never been successful in resoldering them,either.

I do not think this part would be the cause of his intensity
modulation.

Followup: The frequency of the chopped line does NOT correlate with
line frequency.

Perhaps HV oscillator freq?

I don't think so. It's order of a few hundred Hz and not constant.

And I should note that at low intensity, it is worst going full off.
With the intensity turned up, it's not visible. There is minimal
if any geometric distortion of the trace (outside of the focus
problem, which doesn't always appear) so I doubt any LV power supplies
are involved that also feed the amps.

Then you're down to decoupling caps.

It's almost as if the Z input has some oscillation on it. When I
first noticed, I thought maybe the chopped blanking was misbehaving,
but this occurs on all vertical modes.

A thought occurs to me;there's a 1uf/150V(IIRC) electrolytic on the wiper
of the CRT grid bias pot,to ground;that could be going bad.

I'll check that.

It's also related to warmup. At power-on, there is no problem. It
takes a of couple minutes to show up. The fan is running.

And even then, the severity varies randomly.

So, what could affect the Z modulation AND sometimes focus, but not
geometry?

If it was the HV divider I guess a parts unit is the only source for a
replacement?

Yes,it was a TEK-made part,from their defunct hybrid/ICO in-house plant.
Removing a good one from a motherboard without damaging it is not an easy
task

Now it really doesn't like even normal intensity.

But the geometry (beam stiffness, etc.) is not affected. So, I'm
leaning toward a problem in the grid circuit, not the HV itself.

Does anyone know of a free source for decent quality schematics? I have
several complete manuals downloaded from various places but the resolution
of the schematics tends to be terrible and only marginally useful.

I think we have the 465b manual at work, I'll have to check on Mon.
If we do, I'll only be able to copy a couple of pages so I'll just be
able to get the power supply and maybe a few others, but I'll give it
a shot.

--- sam | Sci.Electronics.Repair FAQ: 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 Sites: http://www.repairfaq.org/REPAIR/F_mirror.html

Important: Anything sent to the email address in the message header above is
ignored unless my full name AND either lasers or electronics is included in the
subject line. Or, you can contact me via the Feedback Form in the FAQs.