IBM 7534 Service Manual

[Shadow Lord]

Does anyone have a link to or copy of the service manual for the IBM 7534 EGA monitor? Failing that anyone have any sort of service guides? While my 7534 works fine it needs a bit of fine tuning in the alignment department. Any help is appreciated.

 

[modem7]

If the 'guts' is essentially the same of that of the IBM 5153 EGA monitor, then the adjustments in the following document will be applicable:
http://www.ibm5150.net/docs/Sams_ComputerFacts_5153.zip

If you are not educated in the dangers of working on an opened CRT based monitor, then I strongly recommend that you do the research.

Before making any adjustments, a good idea is to record the present setting of the things that you will be adjusting. In that way, if things go pear shaped, you can 'get back to square 1'.

 

[Shadow Lord]

Thanks for the linkage and advice. I've only opened up the 7534 once so far but internally it is not very impressive. I wouldn't be surprised if it was a normal EGA monitor w/ a glare filter and a foam air filter. I can't even figuer out what the foam air filter is for as there is no fan on the bottom. The only fan is on the back of the unit not on the bottom.

 

[Holmes]

In regards to the foam filter, my first thoughts are if the fan is oriented to blow wind "out" of the monitor unit, then the air will be "sucked" into the monitor casing from the other available open areas (other than the fan opening). If the bottom is the only other open area, then the air will be drawn into the casing there, which is why they put a foam filter there - to prevent dust from getting in.

If the fan "sucks" air into the casing, then I have no ideas about what the foam filter would do.

 

[Shadow Lord]

I agree, in theory that is probably what is suppose to be going on. However, the fan is so small I really don't see that happening. I'll post some pictures of the innards once I re-open the case in a couple of weeks. I need to paint the exterior as well so I have to wait until I can dedicate a day to it.

 

[Chuck(G)]

Fans are the rule on industrial equipment that has to deal with contaminated air and temperature extremes. Look at any industrial rack-count PC (not the ones for servers that demand much easier working conditions).

 

[Shadow Lord]

Agreed, I just don't know how effective the fan is on the 7534.

 

[Shadow Lord]

Agreed, I just don't know how effective the fan is on the 7534.

Okay, I finally got a chance to play with the 7534 some more and I am having a bit of a weird issue. When I run a game like KQ4 or a full screen text application (e.g. NDD or SD) the screen comes out all screwy. However, when I run test patterns they look pretty much dead on. Any ideas? I can try and post screen shots if that would help.

 

[modem7]

Okay, I finally got a chance to play with the 7534 some more and I am having a bit of a weird issue. When I run a game like KQ4 or a full screen text application (e.g. NDD or SD) the screen comes out all screwy. However, when I run test patterns they look pretty much dead on. Any ideas? I can try and post screen shots if that would help.

In EGA, DOS and NDD (NDD from NU6) both run in mode 2 operation (horizontal sync = 21.8 kHz), and so this is not a mode 1 problem (horizontal sync = 15.7 kHz).

Post a photo.

 

[Chuck(G)]

I have a suggestion--make sure that your card isn't set for operation with multisync monitors. Those monitors are very cool, but they employ freqeuncies outside of the normal "stock" EGA display.

Check your switches.

 

[Shadow Lord]

I have a suggestion--make sure that your card isn't set for operation with multisync monitors. Those monitors are very cool, but they employ freqeuncies outside of the normal "stock" EGA display.

Check your switches.

Chuck(G),

That is the first thing I did when I got the card before installation. I checked all the dip switches and reset to stock settings and made sure I was not on multisync (I think the card arrived set as multisync).

 

[Shadow Lord]

In EGA, DOS and NDD (NDD from NU6) both run in mode 2 operation (horizontal sync = 21.8 kHz), and so this is not a mode 1 problem (horizontal sync = 15.7 kHz).

Post a photo.

Alright a few photos:

1. The computer POSTing. Over all I think the picture quality is pretty acceptable for EGA. But never having owned an EGA monitor (I went from CGA to SVGA) I could be wrong. If you look at the left upper corner you can see a little issue.

2. BIOS - I posted this bigger as the problem is with the "bright" colors. Any time the text is in the bright/bold mode the font runs together and looks blurry. Not sure if this is an adjustment issue or a limitation of the technology.

3. KQIV: You can see a problem in both upper corners.

4. SR6. Norton wasn't so bad this is horrible. Not sure if the opening screen is a VGA one or what but it looks horrible. Going to the application itself its no better. I posted this bigger again for detail. the sides of the picture are all wrong and there is a dark band on the right hand side. Almost as if there is a shadow on the picture.

5. The test screens look ok except for the same minor problem in the upper right hand corner.

 

[modem7]

Re the 'Spinrite 6.0' photo, in particular. See how the edges of the raster change with the video content. That is a classic symptom of poor power supply regulation. You may need to replace the filter caps in the power supply.

That might also explain the other screens, except for the opening screen of SR6. That's a horizontal sync issue. So, I suggest that you fix the poor power supply regulation then see what symptoms remain.

 

[Chuck(G)]

If modem7's guess is right about the PSU, that could have been the proximate cause behind the monitor's strange display when you first received it. So, if the PSU needs repair, you may have to lather, rinse, repeat your adjustment routine after you get it fixed.

 

[Shadow Lord]

Re the 'Spinrite 6.0' photo, in particular. See how the edges of the raster change with the video content. That is a classic symptom of poor power supply regulation. You may need to replace the filter caps in the power supply.

How come this only shows up w/ SR6? I guess what i am asking is if it is a PS issue shouldn't I get the same set of problems with all programs?

 

[modem7]

How come this only shows up w/ SR6? I guess what i am asking is if it is a PS issue shouldn't I get the same set of problems with all programs?

The degree varies depending on the amount of instantaneous change in current consumption. At the top of the Sprinrite screen is cyan. All of a sudden, the video changes to about 80% white per line. White is where all three electron guns are 'going at full tilt'. So all of a sudden, significantly more current is drawn from the power supply. A poorly regulated power supply doesn't cope properly with that sudden increase in current properly and the output voltage drops (it should stay at the same output voltage, i.e. regulated).

I can see the same thing happening in the BIOS screen and the first test pattern.

 

[mikey99]

Do you notice any difference in the distortion at different brightness levels ? Does turning the brightness down
lessen the distortion ?

On the IBM 5154 EGA monitors, the original power supply capacitors used were only rated at 85 degrees C.
The 5154 monitors tend to run quite hot inside and this causes the capacitors to fail. I wonder if thats also the
case with the Industrial EGA 7534 monitor. If it was truly designed to work in a more harsh environment, they
should have used better quality components. I've repaired several 5154's (with various problems) by removing
the power supply board and replacing all the electrolytic capacitors with new ones rated at 105 C.

 

[Shadow Lord]

Do you notice any difference in the distortion at different brightness levels ? Does turning the brightness down
lessen the distortion ?

That is a good question that I will have to look into. But I am guessing it is not a definitive diagnostic procedure. I.E. if the level of distortion does not change w/ change in brgihtness that does not necessarily rule out the caps.

 

[mikey99]

I'm curious if the 7534 uses the same PS board as the 5154.

I attached a couple pictures of a 5154 PS board I had laying around. I circled in red the caps that should be changed and in yellow the ones that may be optional. The optional large ones are rather expensive, I think around $4 apiece. This particular PS has a different problem, one of the .1 uf X2 capacitors blew, smoked up my friends workshop pretty good as I recall.....

 

[Shadow Lord]

I'm curious if the 7534 uses the same PS board as the 5154.

I attached a couple pictures of a 5154 PS board I had laying around. I circled in red the caps that should be changed and in yellow the ones that may be optional. The optional large ones are rather expensive, I think around $4 apiece. This particular PS has a different problem, one of the .1 uf X2 capacitors blew, smoked up my friends workshop pretty good as I recall.....

Mikey99,

Thanks for the info. I also found the following bit of advice on the net. I was bidding on a 5154 service guide but I lost and unfortunately I will not have a chance to mess with the monitor again until next week. However, I will post pics of the PS board for you for comparison and report on how the adjusting the brightness affected everything. Thanks for your help so far!