IBM 5155 CGA Video Card Repair (Capacitor Replacement)

[wesleyfurr]

Dug out my IBM 5155 Portable PC a while back and found that the CGA video card had gone bad. In the process of cleaning up and sorting out my piles and boxes of random stuff, I found both an ATI EGA Wonder 800 and a generic-looking Paradise Color/Mono card. Can't seem to find a way to get the EGA Wonder to work with the on-board monitor. Popped in the other one and it worked great! Unfortunately, after a short while of running, there was a pop, a spark, and the computer shut down. Turned it off quickly and extracted the card and found one of the capacitors had blown its top off.

I'm wondering if it might be worth even trying to replace the capacitor, or is something else likely damaged? It's not an electrolytic...perhaps a tantalum type? I can post photos if that would help. There are two others on the card, and they only say "106F", which after looking around online, I'm guessing means it is a 10uf +/- 1%? Assuming it's worth trying to replace, what exactly do I need to get for proper replacement?

Or perhaps someone has a way to get the EGA Wonder to work with the 5155 monitor?

Or maybe some way to fix the original IBM CGA card?

Thanks,

Wesley

 

[modem7]

Welcome to these forums.

I'm wondering if it might be worth even trying to replace the capacitor, or is something else likely damaged? It's not an electrolytic...perhaps a tantalum type? I can post photos if that would help.
There are two others on the card, and they only say "106F", which after looking around online, I'm guessing means it is a 10uf +/- 1%? Assuming it's worth trying to replace, what exactly do I need to get for proper replacement?

It is very likely a Tantalum capacitor, a high failure rate item in vintage computers.
See http://www.minuszerodegrees.net/failure.htm for photos and information.

If replacing it is going to cause a headache (e.g. lack of soldering equipment/skill), then don't bother - just use a pair of wire cutters to snip it off the card.

Or perhaps someone has a way to get the EGA Wonder to work with the 5155 monitor?

See this earlier thread: http://www.vintage-computer.com/vcforum/showthread.php?12973

Or maybe some way to fix the original IBM CGA card?

If the symptom was that the card stopped the 5155 from starting up, then the card might have a Tantalum capacitor that has developed a short circuit.

 

[Maverick1978]

I would personally never suggest chunking a card or motherboard just because a cap or two got blown. Caps are too cheap and easy to replace, even for soldering novices like me! Best case, you replace the cap and get years more use out of the board. Worst-case, you ruin the board that you were going to toss anyways, so you're back where you started: replacement. You've nothing to lose by trying to fix it, so I say go for it!

 

[wesleyfurr]

Thanks for your thoughts and excellent link! Good (sorta) to know that is a fairly common failure point, and likely hasn't killed anything else. It looks exactly like the photo of the yellow one that is blown, except it is a reddish-orange color. And as noted in the link, hadn't been powered on in years. I don't even begin to consider myself an expert at soldering, but I've also replaced enough odd small things (mainly capacitors) that my boss is amazed... I'll see if I can dig up an appropriate replacement and do it right. Does it need to be a tantalum, or would a small electrolytic suffice? Any thoughts on whether or not it really is a 10uf 1%?

As for the EGA Wonder, I'm not getting any beeps or anything, and the monitor is just brightly scrambled, leaving me afraid of leaving it powered on for more than a few seconds for fear of damaging the monitor... I think I've tried every applicable setting by going through them one at a time and always end up with the same result on the screen. I guess it's possible the card is bad too...not sure I've ever used it in anything since I got it years ago. I do have an EGA monitor though, guess I should just plug it into that and see what happens. The link in the other forum post just says the guy tried settings until he got one that worked...but neglected to say what that was! :-(

Thanks,

Wesley

 

[Maverick1978]

IIRC, the ATI EGA/VGA Wonder series auto-synched to the type of monitor attached to it. I know that my ATI VGA Wonder-16 does (it's the one with both a 9-pin and 15-pin connector for the two monitor types). I've successfully used it with a 5150 monochrome, 5153 CGA, NEC Multisync at CGA/EGA/VGA resolutions, and an SVGA LCD all without a hitch.

I know that my Paradise EGA card auto-synch's as well IF you set the jumpers appropriately. I'll have to dig out the model number and book tonight and get back to you...

 

[modem7]

Does it need to be a tantalum, or would a small electrolytic suffice? Any thoughts on whether or not it really is a 10uf 1%?

In this application, you can use an aluminium electrolytic, however they are usually taller than the equivalent tantalum, and so you need to ensure that the top of the aluminium electrolytic won't come close to an adjacent card.

Also in this application, the tolerance is not critical (for either tantalum or aluminium electrolytic). +/- 20% for example, will be fine.

 

[modem7]

As for the EGA Wonder, I'm not getting any beeps or anything, and the monitor is just brightly scrambled, leaving me afraid of leaving it powered on for more than a few seconds for fear of damaging the monitor... I think I've tried every applicable setting by going through them one at a time and always end up with the same result on the screen. I guess it's possible the card is bad too...not sure I've ever used it in anything since I got it years ago.

Just remember that even though you are trying to get CGA signals out of your EGA card, the 5155 motherboard switches still have to remain set for EGA (5=on/6=on).

 

[wesleyfurr]

Sorry to bump an old thread...but finally getting around to trying to get this video card fixed. The capacitor that has failed is the same as two others on the card...they all say simply "106F". They do have a + marking, presumably polarity counts with these the same as electrolytics... They are orange or maybe reddish-orange in color. Someone earlier suggested just clipping it off, but seems like it is there for a reason, so I would like to try to replace it. Online notes don't show 6 as an appropriate multiplier? Can anybody tell me what value I need to buy to replace it?

I've got some incentive this time to get around to fixing it - I have the opportunity to show off my old computer "antiques" at a retirement community the end of next month... Spent some time this morning digging around in the shed and seeing what works and doesn't. Found a working IBM 5151 monitor to go with my 5150. Unfortunately after a minute or so of being turned on constant, the PC shut off on me...flipping it off and back on it tries to power up for a brief moment, then shuts back off. :-( Also need to look at the old Apple II+'s that I've got. Found a working Monitor III...one of the II+'s will display "APPLE ][" and do nothing more, the other gives no display. Hopefully just some loose socketed chips or something... Amazing to me that the old monitors seem to be holding up better than the computers they go with!

Anyway...thanks for any thoughts on the capacitor...

Wesley

 

[modem7]

Sorry to bump an old thread...but finally getting around to trying to get this video card fixed. The capacitor that has failed is the same as two others on the card...they all say simply "106F". They do have a + marking, presumably polarity counts with these the same as electrolytics... They are orange or maybe reddish-orange in color. Someone earlier suggested just clipping it off, but seems like it is there for a reason, so I would like to try to replace it. Online notes don't show 6 as an appropriate multiplier? Can anybody tell me what value I need to buy to replace it?

10µF/16V tantalum - a common value on IBM 51xx motherboards and cards.
Details at http://www.minuszerodegrees.net/failure/failure - 3lt.htm

 

[modem7]

Spent some time this morning digging around in the shed and seeing what works and doesn't. Found a working IBM 5151 monitor to go with my 5150. Unfortunately after a minute or so of being turned on constant, the PC shut off on me...flipping it off and back on it tries to power up for a brief moment, then shuts back off.

It is unclear as to whether you are asking for assistance, or simply letting people know of your problem (which you will diagnose later).
In case the former:

The first step is to identify the part of the computer that is causing that symptom.

So start removing all cards from the motherboard, then disconnecting the floppy drive/s from the power supply. What you have then is only the motherboard and power supply. If the symptoms remain, then obviously the cause is either the motherboard or power supply. If the symptoms are gone, start adding the floppy drive and the cards, one by one, looking to see at which point the symptoms reappear.

Note that when powering off/on the power supply, there is usually a requirement of the maker that there be at least a delay of say, 10 to 15 seconds, between the 'off' and the 'on'. I guess that failure to observe that requirement may result in the power supply not restarting. Just letting you know, in case you are unaware. You don't want to be doing something that interferes with your diagnostics.

 

[patscc]

106F boils down to 10uF if it's a tantalum. Theoretically capacitors are standardized, in reality...
They shouldn't just pop like that. Were the cards stored under damp conditions ?
Have you measured the power supply outputs to make sure there's nothing odd, like a large amount of AC ripple ?
Switching power supplies will shut down when confronted with a short, or if there's a internal problem.
patscc

 

[wesleyfurr]

It is unclear as to whether you are asking for assistance, or simply letting people know of your problem (which you will diagnose later).
In case the former:

The first step is to identify the part of the computer that is causing that symptom.

So start removing all cards from the motherboard, then disconnecting the floppy drive/s from the power supply. What you have then is only the motherboard and power supply. If the symptoms remain, then obviously the cause is either the motherboard or power supply. If the symptoms are gone, start adding the floppy drive and the cards, one by one, looking to see at which point the symptoms reappear.

Note that when powering off/on the power supply, there is usually a requirement of the maker that there be at least a delay of say, 10 to 15 seconds, between the 'off' and the 'on'. I guess that failure to observe that requirement may result in the power supply not restarting. Just letting you know, in case you are unaware. You don't want to be doing something that interferes with your diagnostics.

Actually, I was more just commenting than anything. I've been doing computer work for formally and for a living since 1996 (when I graduated from high school) and for the fun of it for several years prior. Thanks for the power supply tip, makes some amount of sense, but I've never run into that being a problem...

I got the 5150 going...but I think I'll start a new thread on that one lest I clutter this up with too many unrelated posts... The short of it is a cap went kaboom on it too... :-( But like I said, it is working for the moment...

Thanks,

Wesley

 

[wesleyfurr]

106F boils down to 10uF if it's a tantalum. Theoretically capacitors are standardized, in reality...
They shouldn't just pop like that. Were the cards stored under damp conditions ?
Have you measured the power supply outputs to make sure there's nothing odd, like a large amount of AC ripple ?
Switching power supplies will shut down when confronted with a short, or if there's a internal problem.
patscc

From what I'm reading (and to some degree experiencing), those old tantalum capacitors like to go kaboom...except it's not nearly as enjoyable as fireworks...

The failed capacitor is on a Paradise Systems "HI RES GRAPHICS CARD". Appears to be mono/CGA with a big switch on it. I picked it up used many moons ago...if I had to guess 15 years ago. I don't know that I ever tried using it until I dropped it into the 5155...at which point I rejoiced with glee until it went "POP!" and the whole thing powered off... It spent at least 5.5 years in the basement of a house I lived in after getting married...so certainly somewhat damp. Since then another 5 years in the unfinished upstairs (read: attic) of our house...yeah, I know, not ideal...but it's either that or throw them out...most of my oldies are now residing in a nice outdoor storage shed.

Thanks,

Wesley

 

[patscc]

It might just have shut off due to the electrodes in the cap touching as it blew. Some switching power supplies are real touchy about perceived shorts.
patscc

 

[wesleyfurr]

I got the replacement capacitors in the mail...and they are actually even labeled 106F. Swapped it out, stuck it in, and the 5155 fired right up! Been messing around ever since seeing if I can get the Microscience HH 612 hard drive to work...I think it's about shot...lots of bad sectors. Oh well... Perhaps I'll dig out another MFM drive from the stash and give it a try...probably all a long shot at this point! Just wish I had a few more XT IDE controllers... Some day...

Thanks all,

Wesley