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IBM 5154 Troubleshooting

There are several repair tips on the following page for the 5154 :

http://www.repairfaq.org/REPAIR/F_IBMmon.html#IBMMON_007

I've had good luck repairing a few 5154 power supplies by just replacing all the electrolytic capacitors on the power supply card. The capacitors
are only rated at 85C degrees and tended to overheat in these circuits. I always use 105C rated capacitors for replacement.
You can usually get away with not replacing the two large capacitors.

What are the symptoms of your 5154 ?
 
Thanks for your link but I already knew it. I need the diagrams because I will give my 5154 to a TV repair shop but he needs the diagrams. I don't know anything about electronic ...
Someone gave this 5154 a few days ago. When I powered it up for the first time, after about 30 seconds I could ear a "crack" followed by some white smoke coming from the right side (right side when you are in front of the screen). I then turned off the screen and never powered it back up.

EDIT : by the way, I forgot to ask this question : can I connect the 5154 power cable directly to a power source to power it up or does the 5154 need to receive a video signal to power up ?
 
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If you power on the 5154 with no video signal attached, it should display a white raster.
Turning the brightness control should increase/decrease the intensity of the raster.

The right side is the power supply. Smoke from the power supply usually indicates the
foil capacitor across the mains blew. On page one post #3 of this same thread
I described a similar problem with the "0.1 uf X 2" capacitor.

I do have a schematic for the 5154 somewhere, I'll try to find that tonight......

btw, here's a picture I posted awhile back of the inside of the 5154 PS with the capacitors
circled in red/yellow. You can also see the two 0.1 uf X 2 oil capacitors in the upper left, one of which
is blown in this PS.
 

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mikey99 said:
If you power on the 5154 with no video signal attached, it should display a white raster.
Turning the brightness control should increase/decrease the intensity of the raster.

The right side is the power supply. Smoke from the power supply usually indicates the
foil capacitor across the mains blew. On page one post #3 of this same thread
I described a similar problem with the "0.1 uf X 2" capacitor.

I do have a schematic for the 5154 somewhere, I'll try to find that tonight......

btw, here's a picture I posted awhile back of the inside of the 5154 PS with the capacitors
circled in red/yellow. You can also see the two 0.1 uf X 2 oil capacitors in the upper left, one of which
is blown in this PS.
Click to expand...

Thank you very much for these informations. I guess now I have enough informations to go to the TV repair shop (if you can find the schematics for the EGA 5154 it would be perfect).
 
Dizzy33 said:
Thank you very much for these informations. I guess now I have enough informations to go to the TV repair shop (if you can find the schematics for the EGA 5154 it would be perfect).
Click to expand...

I found the schematic and am scanning it now.....send me a PM with your email ID and I'll send it directly to you.
 
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Hello all, my 5154 has now been repaired. According to the repair shop, the problem was not the power supply but some resistors ...
So now my 5154 does power up, good thing. But I still have a problem : there is a display problem ...
When I power up my 5150, the text displayed is too far on the left side of the screen, I can only read a small part of it. Plus, the display is unstable ...
Then, if I try to run a CGA game, the display becomes stable and well centered, but I miss the left part of the display, and more strange, multiple graphic bugs are displayed on the screen ...
I tried two different EGA cards (EGA Wonder and Quadram QUADEGA), but still the same problems, so the problem does not come from the EGA card. When my 5151 is connected to the EGA card, everything is fine ...

I tried to modify the vertical scroll button on the back of the monitor, still the same... But I can see two small holes close to the vertical scroll buttons, is there anything I can do with it ?
Does anyone know where this display problem may come from ?
 
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The 5154 has two modes of operation:

Mode 1: Think of this as 'CGA' mode.
Mode 2: Think of this as 'Normal' mode.

When you fire up your computer, the 5154 will be in Mode 2 operation. If you then do anything which results in the EGA video card using one of the CGA video modes, the 5154 will switch into Mode 1 (CGA) operation.

A lot of adjustments in the 5154 are in pairs, one of the pair affects Mode 1 only and the other of the pair affects Mode 2 only. The "vertical scroll buttons" you refer to are the two vertical size adjustments (VSISE1/VSIZE2), one for Mode 1 and the other for Mode 2.

Dizzy33 said:
When I power up my 5150, the text displayed is too far on the left side of the screen, I can only read a small part of it. Plus, the display is unstable ...
Then, if I try to run a CGA game, the display becomes stable and well centered
Click to expand...
So this suggests that the horizontal position adjustment for mode 2 (inside the monitor) needs adjustment. It may not be the only adjustment that needs to be changed though.

Dizzy33 said:
But I can see two small holes close to the vertical scroll buttons, is there anything I can do with it ?
Click to expand...
No. Those holes provide access to the SUB BRIGHTNESS and SUB CONTRAST adjustments, unrelated to your issue.

Dizzy33 said:
Then, if I try to run a CGA game, the display becomes stable and well centered, but I miss the left part of the display, and more strange, multiple graphic bugs are displayed on the screen
Click to expand...
A photo will help.


All these kinds of issues are the type that a TV repair shop will have dealt with over the years (but for TVs). I presume that you gave them the 5154 only. If so, I think you need to take the 5154 back together with your computer, providing:
1. the knowledge above that there are 2 modes of operation; and
2. instructions on what to do on the computer that results in the 5154 switching between Modes 1 and 2.

As for 2. above, CheckIt software can be used. See the bottom section of http://www.minuszerodegrees.net/mda_cga_ega.htm
And CheckIt will have crude alignment patterns that the TV repair shop can use.
 
Thanks a lot for this answer ! I'll open the monitor and try to adjust the horizontal sync.
 
So I tried to adjust the horizontal sync using the internal button but I couldn't get things better. I modified my EGA Wonder to emulate a CGA 80 Display, and then the screen works fine.
So it seems my screen has a centering problem with MODE 2 but not MODE 1 ...
 
I see there is some info on adjusting the centering in the SAMS documentation,
is that what you adjusted ........RT251/RT204 ?

If you look on the SAMS page PreliminaryChecks6.jpg you'll see the controls
including RT204 in the upper right corner.
 

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I don't know what they call RT204 but it seems to be what I need to adjust ... In the SAMS documentation, I couldn't find RT204 on any of the pictures.
The one I tried to adjust is the one named "horiz width 2" ... I am just realizing that "width" is not for centering the image ...
rear.jpg
 
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Based on the instructions ......you should adjust RT251 first , if that doesn't provide
satisfactory centering you should try adjusting RT204. I attached a section of the
SAMS showing these controls. ***These are on the main board which may be hard to get
to.....be very careful and stay away from that big red wire on the top of the CRT !
If possible use a long plastic tool to adjust those controls, to reduce the chance of
shorting something. Its a good idea to make note of the original position of the control
so it can be returned to its original setting if necessary......
 

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thanks a million again Mikey ! My only problem now is that I'm always afraid of working inside TV/monitors because of the high voltages ...
I'll try but if it's too risky I won't do it ...
Can you please tell me where the main board is located : is it right under the screen, or is it what is called the "video board" on the right side of the screen ?
 
The main board is under the CRT......see those two controls at the lower right
of my screen cap.....those are the horiz. width pots you already adjusted. RT251 should
be just a little bit forward from those.....
 
Mikey, I have to thank you a million again !!! Now my 5154 is fixed !!!
So I finally decided to remove the monitor case and adjusted the "horiz 2" centering button ... It wasn't named RT204 but RT226 (if I remember well ...), however they were easy to locate as the button function was written on their base ... It is located (when in front of the screen) on the left side of the screen. It's really accessible.
Then the display was well centered, but it was shaking a bit. So I managed to also adjust the "horiz 2" frequency. This button was close to the RT226. Then the display stopped shaking ... !!!
So I am very happy today as my 5150 restoration is now close to be finished, and with a good configuration (EGA Wonder, 20Mb hard disk, 256K memory expansion ...). I just have now to try to let work a 8 Bit sound cards I plugged in.

Again, Mikey you saved me one more time, you are a great guy !!!
Thanks a million again Mikey !!!
 
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