• Please review our updated Terms and Rules here

5154 Monitor PSU: Capacitors for 200-240VAC

S

stepleton

Veteran Member
Joined
Jan 1, 2020
Messages
535
Location
London, UK
The patient is an IBM 5154 display that has been recapped by someone who used no-name parts. The voltage ratings on the "new" post-rectification DC smoothing caps (the two big ones) seem suspiciously low for the rectified AC mains, and anyway one of them is quite bulged.

I'd like to replace the bad capacitors with better parts, so I visit https://caps.wiki/wiki/IBM_5154_EGA_Display for details. Helpfully, it says:

"There is a slight different list of capacitors for the 110V and the 220V versions of this display, so make sure you are looking at the correct list of caps."

The wiki page goes on to present exactly one list of capacitors.

Does anyone know the correct specifications for the electrolytic capacitors in a 5154 power supply that runs on 200-240VAC?
 
Before putting my 5154 (200-240VAC) away, I took note of most prominent aluminium electrolytics in the power supply cage:

C7 = 220 µF / 250V
C8 = 220 µF / 250V
C11 = 47 µF / 63V
C13 = 10 µF / 63V
C14 = 1 µF / 63V
C23 = 2200 µF / 25V (see note 1)
C25 = 1000 µF / 25V
C27 = 1000 µF / 63V
C31 = 47 µF / 200V
C29 = 220 µF / 63V (see note 2)

Note 1: The cap brand/look and soldering indicates that in my unit, this cap had been replaced post factory.

Note 2: The circuit diagram in the SAMS Computerfacts document on the 5154 indicates that they found a 100V rated part.
 
Thank you! I guess 250V was the correct rating after all. I'll have to take a closer look at the schematics. Either way, a recap is in order.

I suspect this won't be the last time I talk about this 5154 here. When we turned it on briefly, the raster with no signal was very narrow (circa 2cm) and suspiciously yellow. That's a problem for another time, though.
 
stepleton said:
The patient is an IBM 5154 display that has been recapped by someone who used no-name parts. The voltage ratings on the "new" post-rectification DC smoothing caps (the two big ones) seem suspiciously low for the rectified AC mains, and anyway one of them is quite bulged.

I'd like to replace the bad capacitors with better parts, so I visit https://caps.wiki/wiki/IBM_5154_EGA_Display for details. Helpfully, it says:

"There is a slight different list of capacitors for the 110V and the 220V versions of this display, so make sure you are looking at the correct list of caps."

The wiki page goes on to present exactly one list of capacitors.

Does anyone know the correct specifications for the electrolytic capacitors in a 5154 power supply that runs on 200-240VAC?
Click to expand...
I suspect there are many differences between these PSU's depending on the country of manufacture of the monitor, My IBM 5154002 200-240VAC EGA monitor was made in Finland in 1986, I have seen 2 different Manufactured PSU's that were fitted to the IBM 5153002 200-240VAC CGA monitors.
 
You must log in or register to reply here.
Back
Top