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mirrro
September 12th, 2006, 02:52 AM
Hello,
Recently, I got an old IBM computer monitor ,which I want to know it's kind. (CGA / EGA / VGA)
I did some searches on the Internet, and found few Information about that model, I'v got the
feeling that this is a kind of Industrial machine's monitor.

My questions are:

1. what is the monitor's kind ( cga / ega /vga )
2. the data cable is cut off (and I don't have the connector).

I can see 9 wires in that cable.
IS this mean that it is a CGA connector (9 pins)?, although I read that there were also vga
connectors with 9 pins (compared to the 15 pins - vga)

3. how can I make such connector, can I use an old serial cable's connector (RS232) for cga connector?

Thank.

The monitor pics:
monitor_side_a.jpg and monitor_side_b.jpg are in this link:
the photos (http://t2.technion.ac.il/~smelvin)

http://t2.technion.ac.il/~smelvin

carlsson
September 12th, 2006, 04:41 AM
Hm, a bit tricky to get access to your images. Direct linking was forbidden by the web server, so I had to go to your home directory and fortunately there was an automated directory listing so I could click on the file name.

For the others, the model number is 7534-A01 (120V model), made in Taiwan for IBM Armonk, NY. Manufactured in March 1986. It has two knobs on the back side for vertical size 1 and 2. On the front, it says 7534-96H-0003519. On the left side, it has a red power button and wheels for contrast and brightness.

According to Google, this is an IBM Industrial EGA Graphics Display, just like mirrro suggested.

http://choiceprinters.com/video/oldtech.html

I believe the connector should be a DB9 male, i.e. you could possibly use a serial port from a PC or expansion card which has a lead to the connector instead of surface mounted. Otherwise, buy yourself a DB9 connector from a well sorted electronics store; they should still be somewhat common.

mirrro
September 12th, 2006, 07:54 AM
Anders, Thanks for the link problem, I changed the post..
(but How do I change the title also?)

Suppose I got the DB9 male connector,
How do I know How to match the wires which in the cable (in different colors) to the pins in the DB9 male connector?

I suppose that it's one order for CGA and another for EGA..

carlsson
September 13th, 2006, 05:01 AM
EGA pinout: http://pinouts.ru/Video/EGA_pinout.shtml

Which colour is which in the cable .. heh, that is a good question. No idea, unless you can open the monitor and follow each wire and determine it that way.

modem7
September 14th, 2006, 02:35 AM
How do I know How to match the wires which in the cable (in different colors) to the pins in the DB9 male connector?

Option 1:
Per Carlsson's, "open the monitor and follow each wire". Those wires will terminate on one or more circuit boards in the monitor. If you're lucky, there may be signal markings (e.g. "HS" would mean horizontal synch) on the circuit board. If not, you will need access to someone who has a schematic diagram for the monitor AND the skills to match the schematic to components on the circuit board.

Option 2:
Find someone who has the same monitor and get them to dismantle their DB9 connector and report the 'colour-to-pin' assignments. This won't necessarily work with the first person you locate because different manufacturing batches of the monitor may use different cables (i.e. different coloured wires and/or different colour-to-pin assignments).

I think option 2 is the best to aim for initially.
Anyone out there with an 7534 that they're willing to take a peak in the DB9 connector for mirrro? 5154's may use the same 'colour-to-pin' assignment.

mikey99
September 14th, 2006, 08:44 AM
.
.

I think option 2 is the best to aim for initially.
Anyone out there with an 7534 that they're willing to take a peak in the DB9 connector for mirrro? 5154's may use the same 'colour-to-pin' assignment.

I have a working 5154 , I can open the db9 connector and
add wire colors to the pinout provided above. I might be able
to do this tonight.....

carlsson
September 14th, 2006, 08:47 AM
But are the 5154 and 7534 internally the same beast, manufactured in the same factory or even year? Even if both are EGA monitors, it might not say much unless IBM through all years (at least 1981-1991) had a well defined standard on colour coding the cable.

mikey99
September 14th, 2006, 09:06 AM
But are the 5154 and 7534 internally the same beast, manufactured in the same factory or even year? Even if both are EGA monitors, it might not say much unless IBM through all years (at least 1981-1991) had a well defined standard on colour coding the cable.

I have a second 5154 on my bench undergoing surgery :-)
Needs leaky capacitors transplant.....UPS tracking shows
parts will be delivered today.... surgery scheduled for this weekend.

I can post a photo of the inside if you'd like to compare the
monitors. I'll try to use macro and get a closeup of the area
where the cable attaches to the circuit board !

carlsson
September 14th, 2006, 09:20 AM
If you take a picture of a 5154 circuit board, won't mirrro need to open his 7534 to check if the circuit board looks the same? ;-)

Not trying to be demeaning, but I know from experience with other computers (namely Commodore) that not even different batches of the same model (e.g. a Datassette or a power supply) use the same colours or sometimes the colours are swapped. Perhaps IBM was more strict on this when outsourcing the manufacturing.

mirrro
September 14th, 2006, 01:26 PM
I'll open the monitor's case tomorrow , and show you the
results...
Thanks for the help guys!

mikey99
September 14th, 2006, 05:34 PM
I'll open the monitor's case tomorrow , and show you the
results...
Thanks for the help guys!

I opened the connector. Looking at the backside where
the wires attach, the pins on the connector are numbered
1-9 . I copied the chart from the link above and added
the wire colors. Also took a couple pictures of the connector.

Pin Color Name Description
1 BLACK GND Ground
2 ORANGE SR Secondary Red
3 RED PR Primary Red
4 PURPLE PG Primary Green
5 BLUE PB Primary Blue
6 BROWN SG/I Secondary Green / Intensity
7 YELLOW SB Secondary Blue
8 GREY H Horizontal Sync
9 WHITE V Vertical Sync

Heres a couple of pictures of the connector and also one of the inside
which I took a few days ago. I can take more of the inside if necessary
to confirm its the same monitor internally. Sorry for the low-res but
I had to shrink the files to <90KB to be able to upload to the forum:

mirrro
September 15th, 2006, 12:59 AM
micey , I can't see the "one-five.jpg"...

I opened the case.
There is one different between mikey99's monitor:
I have a green wire, and mikey has a brown wire.
The data cable is connected (9 wires) to a main board and from that board there are connections to othere sites in the monitor (e.g: setting buttons , monitor's tube , voltage area..)

It is hard to trace the wire's paths (on the board) becuase those paths pass through chips (and I dont know the gate's chart of that chips)

It can be said from my photos that the grey wire goes to the H.sync (like mikey's monitor) :))) (good start)

Can you state something else from my photos..?

again I put my photos in:
http://t2.technion.ac.il/~smelvin/

over_view.jpg : just over view photo
data_cable.jpg : the plug that goes in to the main board
data_cable_cutted_side.jpg : the over side in the data cable.
main_board_back.jpg : the main board (with the plug location)

main_board_front.jpg : front side, (I fliped the picture in order to maintain the components's location (plug , chips..) .. So all text in mirrored..

mirrro
September 15th, 2006, 01:04 AM
mybe it is worth to try to stick to mickey's chart.
and just replace "brown" with "green"....
??

mikey99
September 15th, 2006, 05:59 AM
mybe it is worth to try to stick to mickey's chart.
and just replace "brown" with "green"....
??

I will take a picture in my monitor similar to your:
data_cable.jpg : the plug that goes in to the main board

modem7
September 15th, 2006, 03:27 PM
mirro,

Those photos of your board are very helpfull. Looking at the back of the board:

First, I can see that the black pin of P204 is ground (what I expected). That corresponds with micky99's colour-to-pin list.

Next, the grey pin of P204 directly goes to another connector labled "H". And so grey is the horizontal synch. That corresponds with micky99's colour-to-pin list.

That leaves us to determine 6 colour signals and the vertical synch.
I expect that the 6 colour signals use identical circuitry, and you can see in the 7 unaccounted-for P204 pins that 6 of them do share common circuitry.
That suggests that the white pin of P204 is the vertical synch. That pin goes to IC Q202 (which I can't identify the part number of from your 'front' photo). One of the pins from IC Q202 heads off to a connector labled "V". Without knowing what IC Q202 is, a link can't be confirmed, however when you factor in that:
a) the other unaccounted-for P204 pins share common circuitry (highly suggesting the colour signals), and
b) micky99's colour-to-pin list has the white wire as vertical sync,
then I'm comfortable saying that the white is the vertical sync.

The identification of horizontal and vertical sync is the important identification. If identification of the colour signals is wrong, all you'll see on the screen is wrong colours.
We've definately identified horizontal synch. I'm 99% confident that we've identified vertical synch.

Therefore, if I was in your situation, I'd be using micky99's colour-to-pin list (substituting brown with green).

If you can give me the part number of IC Q202, I might be able to turn that 99% into 100%.

mikey99
September 15th, 2006, 07:43 PM
I'm surprised that these monitors are so different inside.
I always thought that IBM Industrial components were
the same internals with just a more robust outer shell.
Obviously thats not the case.

My 5154 was made in Korea , and apparently the
7534-A01 was made in Taiwan. Interesting.

mirrro
September 16th, 2006, 10:42 AM
modem 7, you are a realy expert.
I added the Ic_Q202 photo in
http://t2.technion.ac.il/~smelvin

modem7
September 16th, 2006, 10:03 PM
I like some of this forum's readership have an electronics background.
With IC Q202 being a 7486, I can now confirm that the white pin in P204 is the vertical sync.

Cable your DB9 connector per micky99's colour-to-pin list (substituting brown with green). The probability is very high that the colour signals in your monitor use the same coloured wires as mickey's.
If you get incorrect colours on your screen, I should be able to trace out more of the schematic from your pictures, and determine the correct wires.

mirrro
September 17th, 2006, 12:29 PM
I will make the connector tomorrow, and will show you the results..

mirrro
September 18th, 2006, 04:42 AM
Work was done, but there is a little color mismatch problem.

I connected the data cable according to mikey's pinout
(brown <--> green)

I used "CARD Monitor Test Program" to show colors patterns.
http://www.ers.kestar.com.au/dos.html

I run the program in DOSBOX (while setting "machine=ega" , in the "dosbox.conf" file)
and got a result,
then I run the same program on 286, with EV659 ega card.


about the video card.
http://www.codemicro.com/store/check_price.php?partid=1582065
it is an EGA with LPT (I think) controller.
There are jumpers on the side and I dont know what they are configure...

you can look at the photos.
http://t2.technion.ac.il/~smelvin in /part2

bios.jpg : bios screenshot , EGA is set ,but I can choose between EGA , COLOR 80, COLOR 40 , and MONO


color_test_1.jpg
color_test_2.jpg
EV659_card_back.jpg
EV659_card_connectors.jpg
EV659_card_front.jpg
jumpers.jpg : don't know what they are for..

modem7
September 19th, 2006, 03:53 AM
Getting close!

The colour mismatch shown is a green/blue one - green swapped with blue.
just confirm that you wired the connector properly. If okay, try swapping the wires to pins 4 and 5.

That thing you are referring in the picture as "jumpers" is a switch block. Jumpers are those little 'post like' things in the middle of the board that you can remove. I advise you to leave both the switch block and the jumpers set as they are for now, because the problem appears to be in the connector.

Leave the BIOS set to EGA. 'Color 80' is CGA at 80 characters width, and 'Color 40' is CGA at 40 characters width.

modem7
September 20th, 2006, 04:16 AM
If you've confirmed that you wired the connector properly, and now you've decided to swap the wires to pins 4 and 5 (per my previous post), note that you may need to also swap wires for the 'secondary blue' signal and the the 'secondary green' signal (pins 6/7). Experiment as much as you like with the colour signals in EGA because it won't do any damage.

I've got some spare time coming up in the next few days. I can trace out more of the schematic and hopefully give you some definate answers.

mirrro
September 20th, 2006, 06:35 AM
Good news and bad news!

Good news: work done!:cool:
It took me an hour to figure out the right pinout!

which is:
1 BLACK (GND Ground)
2 RED (Secondary Red / Intensity)
3 ORANGE (Primary Red)
4 YELLOW (Primary Green)
5 GREEN (Primary Blue)
6 BLUE (Secondary Green / Intensity)
7 PURPLE (Secondary Blue / Intensity)
8 GREY (Horizontal Sync)
9 WHITE (Vertical Sync)

I was helped by this color pattern
http://en.wikipedia.org/wiki/Image:AdditiveColorMixing.png

I swapped the wires (live) and got the right result!
(I used additional wires for the swapping part)..

Without your help I would try it for (9!=362880) times ---> more than a hour!!

Bad news:
Finally as happy and pleased man I soldered and packed the wires and the connector,
Turned on the pc and got screen darted and mixed with some white. (not paint)

It looked like some wires are touching each other in the connector..I opened it, and it was perfect soldered.

I decided to go back to the last good condition, so, I took out the connector cover, and used all the additional extended wires (which helped me for swapping), but nothing!!, this weird darting screen was still on.

I remmember that when I turned the monitor on , while the data cable wasn't connected to anything , I got a (white) snow picture, But now I'm getting a yellow snow picture.

I thought I was something in the cabble , so I opened that monitor and disconnected the data plug, but nothing... (still yellow snow)

I really dont know what is it...:confused:
I didn't do anything to the monitor in those few seconds when I packed back the connector...
mybe some kind of a electric short..?
(I turned off the monitor while soldering, of course)

Terry Yager
September 20th, 2006, 07:19 AM
That may explain why the cable was cut off in the first place. I can't picture anyone doing that to a perfectly functional monitor.

--T

mirrro
September 20th, 2006, 09:16 AM
Mybe they just wanted the connector....;)

seriously , That monitor didn't fail in that way, in the last two weeks while I was working on it.

modem7
September 20th, 2006, 08:12 PM
Hmmm! Previously with no data cable at all, monitor showed white snow (as expected - equal noise in red/green/blue circuitry). Monitor (minus data cable) now shows yellow snow suggesting full/partial failure of blue. Also have 'darting screen' when an EGA video source is applied.

POSSIBLE CAUSE 1: After redoing the connector, a short in the connector (wire to wire and/or wire to metal connector case) has damaged the monitor.

POSSIBLE CAUSE 2: Faulty monitor all this time - just intermittent. Reappearance of symptoms coincidental with reassembly of connector.

Re possible cause #1. You've indicated that the connector was soldered properly ("it was perfect soldered"). So that tends to rule out possible cause #1. Also, because all of the signals in the EGA cable are TTL level AND are all received by the monitor, any shorts would damage the source (the video card) over the destination (the monitor).

Re possible cause #2. Like Terry, I favour this one. I think someone is more likely to cut off the connector as a sign that the monitor is damaged. I've had co-workers do that. Now, if indeed your monitor is intermittent, it means that the symptoms will eventually disappear (either on power-up of the monitor [electrical provocation] or after physical movement, or on its own accord).

Terry Yager
September 20th, 2006, 08:35 PM
Yeah, dat's what I was thinkin'...#2 (aka, ca-ca).

--T

nige the hippy
September 21st, 2006, 03:48 AM
check for dry joints on the cathode driver transistors, 3 identical power transistors, here on the left of the main board (often found on the tube-base board) they get hot, and are inclined to cause single-colour faults.

Also check for dry joints everywhere else, especially where things get hot. e.g. line output transformer, and it's driver transistor, and round voltage regulators, and anywhere the boards have browned a bit. if you find a joint that looks grey and crystalline, suck it clean & re-solder it.

Do this whole job with a hot soldering iron ready at your side, then it's no trouble to repair even the most slightly suspect joints, otherwise you'll be lazy!

good chance you'll cure the prob.

modem7
September 22nd, 2006, 06:22 PM
You have two sets of symptoms (low/no blue + darting screen). With multiple symptoms, you just investigate/rectify one symptom at a time. Quite often, fixing one symptom removes other symptoms. As your symptoms appeared at the same time, it suggests a common cause.
The 'no/low blue' symptom is the one I'd be investigating first.

Did you try Nige's suggestion?

mikey99
September 22nd, 2006, 09:01 PM
What exactly is a "darting screen" ?

Terry Yager
September 22nd, 2006, 09:37 PM
What exactly is a "darting screen" ?


Well, ya git a couple of drunks inna bar, and hand 'em some sharp objects with feathers at t'other end, and each 'player' gets three chances to try and put out the eye of an innocent bystander, all of which is captured on the tavern's security cam...

--T

mikey99
September 23rd, 2006, 05:53 AM
Well, ya git a couple of drunken M/F-ers inna bar, and hand 'em some sharp objects with feathers at t'other end, and each 'player' gets three chances to try and put out the eye of an innocent bystander, all of which is captured on the tavern's security cam...

--T

Ahhh, now I see (now I don't) , thanks for the clarification Terry :-)

mirrro
September 24th, 2006, 12:30 PM
IT'S WORKING !! :D :D
I didn't solder anything inside..
I just packed back the monitor , and tried again, and it was OK!

(mybe , as you said, some wire was touching the big transistor's hit sink)

Thanks alot guys!!:thumbsup:
You were great!!