Thanks Tom and Raymond for the advice. Two questions from a novice
troubleshooter.
1. I don't have access to a 550 uF, 100 volt electrolytic cap. Tom, when
you say "tacking a radial leaded cap across C1512" to you mean soldering it
on the pads and then checking the AC measurement again. Also, I can't find
C-1512 on the board or in the service manual. The manual is for 465B scopes
with B06000 and up. According to the service manual, all caps on the
horizontal amp are in the 4XXX range.
2. Since I don't have a cap anywhere near the 100 volts, is there another
way to check the cap to see if it is faulty?
|
I would leave the +55 V alone for the moment. A small deviation is unimportant and any adjustment might necessitate a recalibration of the 'scope.
Your problems are not caused by the possible deviation of the DC voltages that you measured. After correction of the real problem, if your 'scope needs a recalibration, you may decide to adjust the + 55V, as is part of a full recalibration as per the manual.
As Tom M. writes, 15 V AC on the +110 V line is too much and I'd do as he recommends.
Raymond
|
AM503B battery dead - calibration lost?
Hi everyone.
My AM503B shows error 355 for some days now - NVRAM error.
Checked the battery and it is dead (shouldn't it show "LO" before that?).
Does this mean the calibration is lost?
Thanks!
ST
|
And I'm not too far away from Tom, in Waldorf MD. Dittos on if you are ever in the area.
Mark
toggle quoted message
Show quoted text
On 12/03/2014 10:20 PM, 'Tom Miller' tmiller11147@... [TekScopes] wrote: Hi Kevin,
I am about 100 mi. north of you in Forest Hill, MD so if you ever are in the area, let me know.
Regards,
Tom
----- Original Message -----
From: Kevin Crossett kcrossett@... [TekScopes]
To: TekScopes@...
Sent: Wednesday, December 03, 2014 2:00 PM
Subject: Re: [TekScopes] Re: Tek 465B woes
Hi Tom. I live in Hampton Roads, Virginia. Not sure if there are any Tek
gurus in this region of the country, but would appreciate a mentor. This
high voltage stuff is scary business for someone with no formal training.
|
If all else fails, I've managed to remove a stuck plug-in by upending the scope and removing the bottom panel. It's then possible to dismantle some of the runner assembly and with some gentle bending remove the module. I can't give chapter & verse from memory, but it did work.
|
Shirley: I see these free CRT TVs in the Penny Saver nearly every week. People just don't want to pay to have them hauled away. Old TVs will run you ragged with repair bills for the parts alone. Gary On Dec 3, 2014 11:02 PM, "Shirley M¨¢rquez D¨²lcey mark@... [TekScopes]" <TekScopes@...> wrote:
In most places these days, people are regularly giving away CRT TVs. Yes,
giving them away for nothing. If you just want a replacement, keep an eye
on Craigslist for a couple of weeks; one or more will probably show up. (A
search here in the Boston area turned up three that were posted in the last
three days.) There will be especially rich possibilities after Christmas; a
lot of them are likely to go out to the curb just after new flat screens
arrive as holiday presents.
I don't want to discourage you from fixing the set you have. But if you're
not prepared to deal with the hassles of working on a high voltage device,
it might be more practical to just find a replacement.
On Thu, Dec 4, 2014 at 1:42 AM, 'Richard R. Pope' mechanic_2@...
[TekScopes] <TekScopes@...> wrote:
Hello all,
I want to apologize for taking so long to get back with everyone.
My fibromyalgia is acting up. To everyone I am disabled, unable to work,
on social security disability, and very short of money. So I will have
to repair this TV. I do not have the money to buy a Sam's manual. It is
sad that the ESI manual is broke. I have downloaded quite a few manuals
from them over the years and they have been very good. The hints and
tips that I have been given by so many people will be of great help once
I am able to climb into this thing. I understand what the dangers are
and I have repaired TVs in the past. I just wanted to get an idea of
what to expect with this model. I appreciate all of the help.
Thanks,
rich!
On 12/3/2014 8:07 AM, taylorvandy@... [TekScopes] wrote:
Give Talon Electronics a buzz. George is an old-timer that understands
TVs - and they will have your service manual, in PDF form. The B
series were among the last Zenith sets made.
Talon is also the place to go for the old degaussing thermistors used
in CRT televisions, glad I found them before buying on eBay.
Taylor
[Non-text portions of this message have been removed]
|
Also look at the freecycle groups. Just google it. And yes, there will be tons of crt tvs after xmas.
toggle quoted message
Show quoted text
----- Original Message -----
From: Shirley M¨¢rquez D¨²lcey mark@... [TekScopes]
To: TekScopes@...
Sent: Thursday, December 04, 2014 2:02 AM
Subject: Re: [TekScopes] Zenith 36" problem!
In most places these days, people are regularly giving away CRT TVs. Yes,
giving them away for nothing. If you just want a replacement, keep an eye
on Craigslist for a couple of weeks; one or more will probably show up. (A
search here in the Boston area turned up three that were posted in the last
three days.) There will be especially rich possibilities after Christmas; a
lot of them are likely to go out to the curb just after new flat screens
arrive as holiday presents.
I don't want to discourage you from fixing the set you have. But if you're
not prepared to deal with the hassles of working on a high voltage device,
it might be more practical to just find a replacement.
On Thu, Dec 4, 2014 at 1:42 AM, 'Richard R. Pope' mechanic_2@...
[TekScopes] <TekScopes@...> wrote:
>
>
> Hello all,
> I want to apologize for taking so long to get back with everyone.
> My fibromyalgia is acting up. To everyone I am disabled, unable to work,
> on social security disability, and very short of money. So I will have
> to repair this TV. I do not have the money to buy a Sam's manual. It is
> sad that the ESI manual is broke. I have downloaded quite a few manuals
> from them over the years and they have been very good. The hints and
> tips that I have been given by so many people will be of great help once
> I am able to climb into this thing. I understand what the dangers are
> and I have repaired TVs in the past. I just wanted to get an idea of
> what to expect with this model. I appreciate all of the help.
> Thanks,
> rich!
>
> On 12/3/2014 8:07 AM, taylorvandy@... [TekScopes] wrote:
> >
> > Give Talon Electronics a buzz. George is an old-timer that understands
> > TVs - and they will have your service manual, in PDF form. The B
> > series were among the last Zenith sets made.
> >
> >
> > Talon is also the place to go for the old degaussing thermistors used
> > in CRT televisions, glad I found them before buying on eBay.
> >
> >
> > Taylor
> >
> >
> >
> >
>
>
>
>
>
[Non-text portions of this message have been removed]
|
Shirley, That is a really good idea. Let's pray that this one lasts until then. 3 weeks and county. Thanks, rich! On 12/4/2014 1:02 AM, Shirley M¨¢rquez D¨²lcey mark@... [TekScopes] wrote:
In most places these days, people are regularly giving away CRT TVs. Yes,
giving them away for nothing. If you just want a replacement, keep an eye
on Craigslist for a couple of weeks; one or more will probably show up. (A
search here in the Boston area turned up three that were posted in the
last
three days.) There will be especially rich possibilities after
Christmas; a
lot of them are likely to go out to the curb just after new flat screens
arrive as holiday presents.
I don't want to discourage you from fixing the set you have. But if you're
not prepared to deal with the hassles of working on a high voltage device,
it might be more practical to just find a replacement.
On Thu, Dec 4, 2014 at 1:42 AM, 'Richard R. Pope' mechanic_2@...
[TekScopes] <TekScopes@...> wrote:
|
In most places these days, people are regularly giving away CRT TVs. Yes, giving them away for nothing. If you just want a replacement, keep an eye on Craigslist for a couple of weeks; one or more will probably show up. (A search here in the Boston area turned up three that were posted in the last three days.) There will be especially rich possibilities after Christmas; a lot of them are likely to go out to the curb just after new flat screens arrive as holiday presents. I don't want to discourage you from fixing the set you have. But if you're not prepared to deal with the hassles of working on a high voltage device, it might be more practical to just find a replacement. On Thu, Dec 4, 2014 at 1:42 AM, 'Richard R. Pope' mechanic_2@... [TekScopes] <TekScopes@...> wrote:
Hello all,
I want to apologize for taking so long to get back with everyone.
My fibromyalgia is acting up. To everyone I am disabled, unable to work,
on social security disability, and very short of money. So I will have
to repair this TV. I do not have the money to buy a Sam's manual. It is
sad that the ESI manual is broke. I have downloaded quite a few manuals
from them over the years and they have been very good. The hints and
tips that I have been given by so many people will be of great help once
I am able to climb into this thing. I understand what the dangers are
and I have repaired TVs in the past. I just wanted to get an idea of
what to expect with this model. I appreciate all of the help.
Thanks,
rich!
On 12/3/2014 8:07 AM, taylorvandy@... [TekScopes] wrote:
Give Talon Electronics a buzz. George is an old-timer that understands
TVs - and they will have your service manual, in PDF form. The B
series were among the last Zenith sets made.
Talon is also the place to go for the old degaussing thermistors used
in CRT televisions, glad I found them before buying on eBay.
Taylor
[Non-text portions of this message have been removed]
[Non-text portions of this message have been removed]
[Non-text portions of this message have been removed]
|
Hello all,
I want to apologize for taking so long to get back with everyone.
My fibromyalgia is acting up. To everyone I am disabled, unable to work,
on social security disability, and very short of money. So I will have
to repair this TV. I do not have the money to buy a Sam's manual. It is
sad that the ESI manual is broke. I have downloaded quite a few manuals
from them over the years and they have been very good. The hints and
tips that I have been given by so many people will be of great help once
I am able to climb into this thing. I understand what the dangers are
and I have repaired TVs in the past. I just wanted to get an idea of
what to expect with this model. I appreciate all of the help.
Thanks,
rich!
toggle quoted message
Show quoted text
On 12/3/2014 8:07 AM, taylorvandy@... [TekScopes] wrote:
Give Talon Electronics a buzz. George is an old-timer that understands
TVs - and they will have your service manual, in PDF form. The B
series were among the last Zenith sets made.
Talon is also the place to go for the old degaussing thermistors used
in CRT televisions, glad I found them before buying on eBay.
Taylor
|
Re: Light bulbs for A8 scale illumination pcb of 2445A?
Here is a better part:
HTH,
Tom
toggle quoted message
Show quoted text
----- Original Message -----
From: 'Tom Miller' tmiller11147@... [TekScopes]
To: TekScopes@...
Sent: Wednesday, December 03, 2014 5:39 PM
Subject: Re: [TekScopes] Re: Light bulbs for A8 scale illumination pcb of 2445A?
That will be too dim.
This is what is used:
CML 715 5 volts, 0.115 A, T-1, wire leads.
----- Original Message -----
From: sadosp@... [TekScopes]
To: TekScopes@...
Sent: Wednesday, December 03, 2014 5:05 PM
Subject: [TekScopes] Re: Light bulbs for A8 scale illumination pcb of 2445A?
|
All those voltages look good. Since the +55 volts serves as the reference for the other rails, and it is slightly low, so are the others.
There is an adjustment, R1538, that sets the +55 level. If you are satisfied that your DMM is within calibration, you might make that adjustment.
When you measure the AC on top of a DC level, you need to wait until the input capacitor for the meter is fully charged. When the AC voltage stops dropping, you have a good reading of ripple.
15 volts AC on the +110 line is not good. I would suspect C-1512, a 550 uF, 100 volt electrolytic cap. You could try tacking a radial leaded cap, say a 470 uF/ 100 volt or higher across C1512 and see if the ripple decreases.
Hit me with a direct email and I'll let you know a phone number you can reach me at if you need some verbal handholding.
Regards,
Tom
toggle quoted message
Show quoted text
----- Original Message -----
From: Kevin Crossett kcrossett@... [TekScopes]
To: TekScopes@...
Sent: Wednesday, December 03, 2014 9:37 PM
Subject: Re: [TekScopes] Re: Tek 465B woes
Ok. Mission accomplished. Here are my measurements and an image to make
sure I probed the right test points.
Test Point Measurement (VDC)
-8 -7.97
+15 +14.98
+55 54.86
+5 4.97
+110 110.5
It seems the power supply is OK on DC voltage. Just for kicks, I also
measured all the test points on AC. All but the +110 line went
progressively down. I stopped the measurements at .4 volts. The +110 line
baselined at about 14 volts AC.
?
[Non-text portions of this message have been removed]
|
Hi Kevin,
I am about 100 mi. north of you in Forest Hill, MD so if you ever are in the area, let me know.
Regards,
Tom
toggle quoted message
Show quoted text
----- Original Message -----
From: Kevin Crossett kcrossett@... [TekScopes]
To: TekScopes@...
Sent: Wednesday, December 03, 2014 2:00 PM
Subject: Re: [TekScopes] Re: Tek 465B woes
Hi Tom. I live in Hampton Roads, Virginia. Not sure if there are any Tek
gurus in this region of the country, but would appreciate a mentor. This
high voltage stuff is scary business for someone with no formal training.
Where are you located? Maybe someone on the list lives near you and can
help you learn this stuff.
Regards
----- Original Message -----
From: Kevin Crossett kcrossett@... [TekScopes]
To: TekScopes@...
Sent: Wednesday, December 03, 2014 9:17 AM
Subject: [TekScopes] Re: Tek 465B woes
Thanks to everyone who has emailed the list with suggestions for me to try
to cure my ailing scope. I have a copy of the service manual and have taken
a look at the various schematics. To say I'm intimated is an
understatement. Just looking at the voltages coming out of this unit scares
me. I am just starting out on this electronics hobby path, and spend my
time playing with low voltage DC circuits. To be honest, I'm not even sure
how to go about checking the voltage within the unit, and forget about
techniques to determine ripple on the supply. I have trouble really
understanding what is going on in a typical RC circuit, and that's just
running off a nine-volt battery. I'm afraid this one is over my head. It's
a shame as I really like the scope, and I'm finally in a position with my
family life that I can start fiddling with it. The scope had been in
storage for about a year as I focused on my family and work.
Again, thanks to everyone who gave some practical suggestions. I will file
them away. And if I can't find someone who has experience with these scopes
and who can take a look at it, then, one day, when I feel more confident
playing with high-voltage equipment, I might drag it out and see about
repairing it.
OK, back to my lurking status.
Kevin
On Wed, Dec 3, 2014 at 12:34 PM, 'Tom Miller' tmiller11147@...
[TekScopes] <TekScopes@...> wrote:
>
>
> Where are you located? Maybe someone on the list lives near you and can
> help you learn this stuff.
>
> Regards
>
> ----- Original Message -----
> From: Kevin Crossett kcrossett@... [TekScopes]
> To: TekScopes@...
> Sent: Wednesday, December 03, 2014 9:17 AM
> Subject: [TekScopes] Re: Tek 465B woes
>
> Thanks to everyone who has emailed the list with suggestions for me to try
> to cure my ailing scope. I have a copy of the service manual and have taken
> a look at the various schematics. To say I'm intimated is an
> understatement. Just looking at the voltages coming out of this unit scares
> me. I am just starting out on this electronics hobby path, and spend my
> time playing with low voltage DC circuits. To be honest, I'm not even sure
> how to go about checking the voltage within the unit, and forget about
> techniques to determine ripple on the supply. I have trouble really
> understanding what is going on in a typical RC circuit, and that's just
> running off a nine-volt battery. I'm afraid this one is over my head. It's
> a shame as I really like the scope, and I'm finally in a position with my
> family life that I can start fiddling with it. The scope had been in
> storage for about a year as I focused on my family and work.
>
> Again, thanks to everyone who gave some practical suggestions. I will file
> them away. And if I can't find someone who has experience with these scopes
> and who can take a look at it, then, one day, when I feel more confident
> playing with high-voltage equipment, I might drag it out and see about
> repairing it.
>
> OK, back to my lurking status.
>
> Kevin
>
>
>
>
>
>
>
|
Ok. Mission accomplished. Here are my measurements and an image to make
sure I probed the right test points.
Test Point Measurement (VDC)
-8 -7.97
+15 +14.98
+55 54.86
+5 4.97
+110 110.5
It seems the power supply is OK on DC voltage. Just for kicks, I also
measured all the test points on AC. All but the +110 line went
progressively down. I stopped the measurements at .4 volts. The +110 line
baselined at about 14 volts AC.
?
[Non-text portions of this message have been removed]
|
Press your thumbs against the bottom corners of the plug-in's front panel and push it inward as hard as you can. Push the release handle all the way in if it isn't already. Then gently pull the release handle out with your right hand, and with your left hand fingertips, reach around the back of the plug-in and pull it outward - you may have to jiggle things around a bit. Make sure the power is off, of course.
If this doesn't work, I think you can remove the plug-in's side panel while it's in there, so you can see the top of the mechanism and try to work it from there. First study another plug-in to see how it's supposed to work.
Once you get it out, inspect for deformed or missing parts, and compare to another plug-in. Also check the slide rail in the mainframe.
|
Would it help to take the side cover off of the 7623?
DaveD
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Show quoted text
On 12/3/2014 3:50 PM, Bert Haskins bhaskins@... [TekScopes] wrote:
Just tried to swap the farthest right plugin to get XY on one of my
7623As and it won't budge.
The pull release seems OK.
What can I try next?
Thanks,
Bert
|
Just tried to swap the farthest right plugin to get XY on one of my 7623As and it won't budge.
The pull release seems OK.
What can I try next?
Thanks,
Bert
|
You could put a Vert amp in a horizontal slot & see if the deflection is the same as the Vert axis.If not, the Horiz amp may need a tweak.
?HankC, Boston
WA1HOS
|
Re: Light bulbs for A8 scale illumination pcb of 2445A?
That will be too dim.
This is what is used:
CML 715 5 volts, 0.115 A, T-1, wire leads.
toggle quoted message
Show quoted text
----- Original Message -----
From: sadosp@... [TekScopes]
To: TekScopes@...
Sent: Wednesday, December 03, 2014 5:05 PM
Subject: [TekScopes] Re: Light bulbs for A8 scale illumination pcb of 2445A?
|
Re: Light bulbs for A8 scale illumination pcb of 2445A?
;hash=item19f64e97e9 ;hash=item19f64e97e9
|
John Sykes
Gary Robert Bosworth
Shirley Dulcey KE1L