Trinitron 19" CRT specs

M

Michael Stan

Guest
I have 2 KDS monitors with Trinitron 19" CTRs. I had to change FLB's in both of
them. I would like to know what the correct values would be for heater voltage
(I found around 6.1V in both of them), G1, G2, HV on these tubes. Also for
katodes. CRTs are M64LMS15X. I couldn't find any documentation at Sony. Somebody
knows? Thanks.

Michael
 
Depending on the CRT type used, some are 12V, but most are 6.3V. If you are
at 6.1V and the CRT is having normal emission, then I would not worry about
this. The tube heater should be having a nice orange type of glow, and not a
very bright yellow. I you were to run a 6.3V heater on 12V, it would not
last very long! The heater would be lit like a light bulb!

The best way is to get the service manual (usually impossible for these), or
to get the specs of the tube. I would not worry about this, if the monitor
is working normally.

--

Greetings,

Jerry Greenberg GLG Technologies GLG
=========================================
WebPage http://www.zoom-one.com
Electronics http://www.zoom-one.com/electron.htm
=========================================


"Michael Stan" <mstan@aci.on.ca> wrote in message
news:gK2dnS3BKsdsjendRVn-hw@edaptivity.com...
I have 2 KDS monitors with Trinitron 19" CTRs. I had to change FLB's in both
of
them. I would like to know what the correct values would be for heater
voltage
(I found around 6.1V in both of them), G1, G2, HV on these tubes. Also for
katodes. CRTs are M64LMS15X. I couldn't find any documentation at Sony.
Somebody
knows? Thanks.

Michael
 
Jerry G. wrote:
Depending on the CRT type used, some are 12V, but most are 6.3V.
Click to expand...
Thanks, Jerry; I thought so. There is no adjustment for heater voltage on the
board. As both boards showed the same reading (6.1V), I thought my DMM is a
little off, at least on this range. I tried with another DMM and it read around
6.3V. So here I'm OK.

If you are
at 6.1V and the CRT is having normal emission, then I would not worry about
this. The tube heater should be having a nice orange type of glow, and not a
very bright yellow. I you were to run a 6.3V heater on 12V, it would not
last very long! The heater would be lit like a light bulb!
Click to expand...
Because of the neck board I cannot clearly see the filaments, but I can see some
orange reflections. I guess it's OK.

The best way is to get the service manual (usually impossible for these), or
to get the specs of the tube. I would not worry about this, if the monitor
is working normally.
Click to expand...
I tried to get the service manual for this EVOKD-1910T, but failed. The business
that sold me the flybacks, which is the one that's doing service for KDS in
Toronto and around, refused to sell the manual. First they said they don't have
it! When I insisted, showing my amazement they can do repair work without the
manual, they admited having it, but refused to sell it. That's the situation.

How about the other voltages, G1 and G2? Knowing the HV value wouldn't do me any
good as I don't have a HV probe; but still I would like to know the right value
for this tube.

I have a strange problem with one of the monitors. It has a definite pink hue.
When I put a white screen (with Nokia program) I get something like a pink
screen. I can adjust from OSD but still the image is not right. On a black
screen, If I increase the brightness I get pink retrace lines.

Having 2 identical monitors allowed me to switch parts in order to pinpoint
where the problem is. I tracked it to the mainboard. When I take the mainboard
from the monitor that have good image and move it in the monitor with redish
image I get a good nice white image. So, it is not the CRT, not the neck board
(where the color guns drivers are located), not the small board where the VGA
cable connects to the monitor, not the cable.

I measured the DC voltages at the CRT pins for RGB with the bad mainboard and
found: 33.3V, 46.8V, 42.2V (RGB). With the good board I got 36.1V, 38.4V, 33.8V.

And I found something else strange on the bad board: the G1 fluctuates; with the
same white image, it went from -1.72V to +6.73V. And it was still moving. (With
the good board I measured -4.45V) Can this produce the redish effect I see? Is
it normal for G1 to fluctuate? Should I look for something faulty in the G1 circuit?

One more observation: I measured the ABL voltage (DC) and found 4.84V with the
good board and 8.50V with the bad board. Maybe that's normal? (2 diferrent
flybacks produce 2 different ABL voltages?)

I would appreciate any idea. I'm not an electronist, just an amateur that tries
to fix his own monitor. Thanks.

Michael
 
For someone that is doing this for a hobby, you atleast have some base
understanding to what is going on!

It does sound like the tube biasing is not right, when compared to the
other monitor. There are a number of factors here. One is that the
main power supply should be verified, and also the secondary voltage
outputs from the flyback section. It is possible that there is a
regulation fault, or voltage source fault.

Also, look for any high ESR capacitors. If there are any that are not
working properly, it would be difficult to have an exact theory of the
effects without some research. But, I have had defective caps cause
some very interesting fault conditioins.

Without the service manual, you will be working sort of blind at this.
The service rep most likely signed a contract of non disclosure about
giving out copies of the service manual. When I was working some
service contracts, with some of the manufactures we had to do the same
thing.

If all the components check out okay in your monitor, the service
setup will have to be verified. For this you will definately require
the service manual, and there may be an interface with software
involved. Many models of monitors are like this.

In the end, it may pay for you to send out the monitor and have the
service rep fix it for you. The repair may be worth it for you, if the
CRT is in very good condition, and if you find the monitor to be of
value to you.

Many of the service shops are jobbing out their work to the
manufacture reps, if any dedicated adjustments, or service techniques
are required. If in the end you determine this, then that will be the
logical solution.

Jerry G.
http://www.zoom-one.com

--


Michael Stan <mstan@aci.on.ca> wrote in message news:<w-OdnXsTItjeo-ndRVn-tA@edaptivity.com>...
Jerry G. wrote:
Depending on the CRT type used, some are 12V, but most are 6.3V.

Thanks, Jerry; I thought so. There is no adjustment for heater voltage on the
board. As both boards showed the same reading (6.1V), I thought my DMM is a
little off, at least on this range. I tried with another DMM and it read around
6.3V. So here I'm OK.

If you are
at 6.1V and the CRT is having normal emission, then I would not worry about
this. The tube heater should be having a nice orange type of glow, and not a
very bright yellow. I you were to run a 6.3V heater on 12V, it would not
last very long! The heater would be lit like a light bulb!

Because of the neck board I cannot clearly see the filaments, but I can see some
orange reflections. I guess it's OK.


The best way is to get the service manual (usually impossible for these), or
to get the specs of the tube. I would not worry about this, if the monitor
is working normally.


I tried to get the service manual for this EVOKD-1910T, but failed. The business
that sold me the flybacks, which is the one that's doing service for KDS in
Toronto and around, refused to sell the manual. First they said they don't have
it! When I insisted, showing my amazement they can do repair work without the
manual, they admited having it, but refused to sell it. That's the situation.

How about the other voltages, G1 and G2? Knowing the HV value wouldn't do me any
good as I don't have a HV probe; but still I would like to know the right value
for this tube.

I have a strange problem with one of the monitors. It has a definite pink hue.
When I put a white screen (with Nokia program) I get something like a pink
screen. I can adjust from OSD but still the image is not right. On a black
screen, If I increase the brightness I get pink retrace lines.

Having 2 identical monitors allowed me to switch parts in order to pinpoint
where the problem is. I tracked it to the mainboard. When I take the mainboard
from the monitor that have good image and move it in the monitor with redish
image I get a good nice white image. So, it is not the CRT, not the neck board
(where the color guns drivers are located), not the small board where the VGA
cable connects to the monitor, not the cable.

I measured the DC voltages at the CRT pins for RGB with the bad mainboard and
found: 33.3V, 46.8V, 42.2V (RGB). With the good board I got 36.1V, 38.4V, 33.8V.

And I found something else strange on the bad board: the G1 fluctuates; with the
same white image, it went from -1.72V to +6.73V. And it was still moving. (With
the good board I measured -4.45V) Can this produce the redish effect I see? Is
it normal for G1 to fluctuate? Should I look for something faulty in the G1 circuit?

One more observation: I measured the ABL voltage (DC) and found 4.84V with the
good board and 8.50V with the bad board. Maybe that's normal? (2 diferrent
flybacks produce 2 different ABL voltages?)

I would appreciate any idea. I'm not an electronist, just an amateur that tries
to fix his own monitor. Thanks.

Michael
Click to expand...
 
Jerry Greenberg wrote:
It does sound like the tube biasing is not right, when compared to the
other monitor.
Click to expand...
Yes, it is something on the mainboard that's producing this.

... There are a number of factors here. One is that the
main power supply should be verified, and also the secondary voltage
outputs from the flyback section. It is possible that there is a
regulation fault, or voltage source fault.

I checked the outputs of the power supply and they are in accordance with the
Click to expand...
schematics (in cases where the expected value is written on the schematics). All
of them seem to be in good order. The heater voltage is not written, it is given
only as a symbol, HT. That's why I asked here about it.

The same stands for the FLB outputs, except for HV (which I don't know and I
cannot measure anyway). I have a FLB line, on the same side as HV and ABL,
called DF-IN. Do you know what it stands for? It may help me understand what the
circuit connected to it is doing.

Also, it is an FLB output marked on the schematics as +900V. This voltage raises
when I raise the HV voltage (using the VR marked HV). Therefore I acted upon
this variable resistance to bring that line at 900V, hoping that the HV line
also comes to the right value (trying to use the measurment of the 900V as in
indirect measurement of the HV). Does this look right to you?

Also, look for any high ESR capacitors. If there are any that are not
working properly, it would be difficult to have an exact theory of the
effects without some research. But, I have had defective caps cause
some very interesting fault conditioins.

I followed this usual advice, and, since I don't have an ESR cheching device, I
Click to expand...
replaced all the electrolytic capacitors, on the entire mainboard, except the
main line capacitor, for which I coudn't find a replacement (it's a 330uF, 400V,
25mm diameter). I checked this one for capacitance with a DMM and it looked OK.

Without the service manual, you will be working sort of blind at this.
The service rep most likely signed a contract of non disclosure about
giving out copies of the service manual. When I was working some
service contracts, with some of the manufactures we had to do the same
thing.

Yeah, that could be the cause they don't want to sell it. I perfectly realised
Click to expand...
that I was blind without the manual. That's why I asked here for help. I don't
need the entire manual, just the part or parts relevant to the problem I have.

If all the components check out okay in your monitor, the service
setup will have to be verified. For this you will definately require
the service manual, and there may be an interface with software
involved. Many models of monitors are like this.

Hm. One more complication.
Click to expand...

In the end, it may pay for you to send out the monitor and have the
service rep fix it for you. The repair may be worth it for you, if the
CRT is in very good condition, and if you find the monitor to be of
value to you.

After so many work hours that I have dedicated to it, it became somehow a
Click to expand...
pesonal thing, a "vendetta". I am "at war" with this bloody monitor and I have
to win; otherwise I loose my self-respect. :)

I thank you for your interest in my problem and I hope I'll be getting more good
ideas from you and from this group.

Michael
 
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