Tech: Kortek monitor woes

G

Guest

Guest
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Kortek monitor woes is right.

This monitor was working fine last Christmas. I lost the blue color
just before I was going to sell it to a customer. I set it aside until
now and troubleshot it.

Found the Q107 neckboard transistor had been bent too far and pulled up
a trace on the mounting pad.

I removed the transistor and fixed the trace and then reinstalled the
transistor.

I had a blue color for just a brief second. The I lost it again.

I pulled the chassis and found that Q104 and Q152 were bad. Replaced
those and tried again. No dice.

This time I took a closer look at the neckboard area and found that I
had installed the Q107 neck board transistor backwards.(Duh) Pulled it
and checked it and it tested good. Replaced the chassis mounted
transistors and tried again.

No luck still. I pulled all the transistors and found that I am still
killing the chassis mounted transistors Q103,Q104, and Q152. Q107 is good.

Where do I go from here? What is killing these transistors?
Is it a result of mounting the neckboard transistor incorrectly? I sure
would appreciate somebody's expertise here. I'm running out of patience
and spare transistors.

Thanks

Pat
 

RJ

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Have you tried checking the tube itself with a CRT Checker? I have run
into the same problem and found that one of the guns was going bad. A
little magic with the Rejuventator and problem solved.

Good Luck

RJ
John Dondzila wrote:
> > Where do I go from here? What is killing these transistors?
> > Is it a result of mounting the neckboard transistor incorrectly? I
> > sure would appreciate somebody's expertise here. I'm running out
of
> > patience and spare transistors.
> >
>
> Have you tried swapping the color outputs to see
> if the problem is the tube ? I've got a bunch of
> these and have the same problem with a couple. Change
> the transistor, works good, button it up, walk by it
> later and no blue again.
 
G

Guest

Guest
Archived from groups: rec.games.video.arcade.collecting (More info?)

> Where do I go from here? What is killing these transistors?
> Is it a result of mounting the neckboard transistor incorrectly? I
> sure would appreciate somebody's expertise here. I'm running out of
> patience and spare transistors.
>

Have you tried swapping the color outputs to see
if the problem is the tube ? I've got a bunch of
these and have the same problem with a couple. Change
the transistor, works good, button it up, walk by it
later and no blue again.
 
G

Guest

Guest
Archived from groups: rec.games.video.arcade.collecting (More info?)

Tube tested good earlier but I haven't rechecked it yet. I'll shoot it
later this morning when I get a chance and see what is going on.

Pat D.

RJ wrote:
> Have you tried checking the tube itself with a CRT Checker? I have run
> into the same problem and found that one of the guns was going bad. A
> little magic with the Rejuventator and problem solved.
>
> Good Luck
>
> RJ
> John Dondzila wrote:
>
>>>Where do I go from here? What is killing these transistors?
>>>Is it a result of mounting the neckboard transistor incorrectly? I
>>>sure would appreciate somebody's expertise here. I'm running out
>
> of
>
>>>patience and spare transistors.
>>>
>>
>>Have you tried swapping the color outputs to see
>>if the problem is the tube ? I've got a bunch of
>>these and have the same problem with a couple. Change
>>the transistor, works good, button it up, walk by it
>>later and no blue again.
>
>
 

Vaxx

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for your information, the kortek is the same as an imperial monitor chassis.
Which the manual for it is available on the net.


"Pat D" <patdanis@comcast.net> wrote in message
news:MZWdneCY28zL46vfRVn-1w@comcast.com...
>
> Kortek monitor woes is right.
>
> This monitor was working fine last Christmas. I lost the blue color
> just before I was going to sell it to a customer. I set it aside until
> now and troubleshot it.
>
> Found the Q107 neckboard transistor had been bent too far and pulled up
> a trace on the mounting pad.
>
> I removed the transistor and fixed the trace and then reinstalled the
> transistor.
>
> I had a blue color for just a brief second. The I lost it again.
>
> I pulled the chassis and found that Q104 and Q152 were bad. Replaced
> those and tried again. No dice.
>
> This time I took a closer look at the neckboard area and found that I
> had installed the Q107 neck board transistor backwards.(Duh) Pulled it
> and checked it and it tested good. Replaced the chassis mounted
> transistors and tried again.
>
> No luck still. I pulled all the transistors and found that I am still
> killing the chassis mounted transistors Q103,Q104, and Q152. Q107 is
good.
>
> Where do I go from here? What is killing these transistors?
> Is it a result of mounting the neckboard transistor incorrectly? I sure
> would appreciate somebody's expertise here. I'm running out of patience
> and spare transistors.
>
> Thanks
>
> Pat
 
G

Guest

Guest
Archived from groups: rec.games.video.arcade.collecting (More info?)

VaxX <geoff_gunn@hotmail.com> wrote:
: for your information, the kortek is the same as an imperial monitor chassis.
: Which the manual for it is available on the net.

There are multiple kortek/imperial chasses out there... some are copies of
the 4900, others are copies of the 7000. None of the chasses I've seen match
the schematics I've found on the net.

--
Mark Spaeth mspaeth@mtl.mit.edu
50 Vassar St., #38.265 mspaeth@mit.edu
Cambridge, MA 02139
(617) 452-2354 http://rgvac.978.org/~mspaeth
 

Vaxx

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Must be an Australian thing ??? Seems every 20" Kortek is the same as the
imperials..
"Mark C. Spaeth" <mspaeth@plancherel.mit.edu> wrote in message
news:4236fab5$0$563$b45e6eb0@senator-bedfellow.mit.edu...
> VaxX <geoff_gunn@hotmail.com> wrote:
> : for your information, the kortek is the same as an imperial monitor
chassis.
> : Which the manual for it is available on the net.
>
> There are multiple kortek/imperial chasses out there... some are copies of
> the 4900, others are copies of the 7000. None of the chasses I've seen
match
> the schematics I've found on the net.
>
> --
> Mark Spaeth mspaeth@mtl.mit.edu
> 50 Vassar St., #38.265 mspaeth@mit.edu
> Cambridge, MA 02139
> (617) 452-2354 http://rgvac.978.org/~mspaeth
>
 

Vaxx

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Jun 9, 2004
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On a different note, I got my hands on a good but old(read, TUBES!) manual
for an oscilliscope which has all the plans and schematics to build one. Can
anyone convert a tube schematic to a transistor?? Only has 8 tubes in it.
Anyone?


"Mark C. Spaeth" <mspaeth@plancherel.mit.edu> wrote in message
news:4236fab5$0$563$b45e6eb0@senator-bedfellow.mit.edu...
> VaxX <geoff_gunn@hotmail.com> wrote:
> : for your information, the kortek is the same as an imperial monitor
chassis.
> : Which the manual for it is available on the net.
>
> There are multiple kortek/imperial chasses out there... some are copies of
> the 4900, others are copies of the 7000. None of the chasses I've seen
match
> the schematics I've found on the net.
>
> --
> Mark Spaeth mspaeth@mtl.mit.edu
> 50 Vassar St., #38.265 mspaeth@mit.edu
> Cambridge, MA 02139
> (617) 452-2354 http://rgvac.978.org/~mspaeth
>