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View Full Version : IBM 5160 - Stripdown Cleanup and Repair.



Clint
January 8th, 2017, 04:45 AM
So I have a recent acquisition of 5160 With 5154 Colour Monitor, purchased from ebay both items from the same seller both advertised as dead and not working.

This one was born on 5th December 1984, in Scotland UK.

I did not try powering this on as it was quite dirty inside, it had been shipped with polystyrene around it but I was lucky and landed in perfect condition, I decided to strip it down and then rebuild it before trying it, on the way checking things for obvious issues.

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I decided to recap the PSU, the RIFA's were cracked although not blown, I noticed a purposely cut track on the PCB, anyone know why this was done ?

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After everything was clean I put it back together, I think its cleaned up very nicely :)

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The HDD was not parked, I wonder if it will be ok?

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I tried to turn it on but it did not work, I noticed the fan turned slightly which was a good sign. I stripped it back down to motherboard only and it started, after a little more fiddling I realised the FDD was the problem. With a multimeter set on ohms, I found the 12v rail was shorted to earth, a quick traceback found a 4.7uf 16v tantalum capacitor sitting at position C43 that was short, I filled the gap with a 4.7uf very low ESR Panasonic FC series capacitor.

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Once done without the CGA/Parallel card installed the machine gave post beeps a great sign. I rebuilt the rest of the unit to await further testing once I have a keyboard and a display.

Here are the ISA cards that were installed (I forgot to photo the HDD controller) :

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Now onto the monitor next, it is a 5154002 - the PSU is just doing a high pitched noise and no HT.... I took a brief look but they really didn't want and components to escape its in a serious metal cage, its going to take some getting at.

So I am guessing the PSU either has a fault or the HT circuit has a short and the PSU is shutting down as soon as it tries to start, either way I am guessing there will be a few components in that PSU that will need to be replaced due to age.

Clint
January 8th, 2017, 06:11 AM
Well after a cup of tea and some egg sandwiches curiosity won !

I opened her up and removed the PSU, its riveted together so have to take a trip to the garden workshop and drill them out, the PSU although looking hot in a few places did not look too bad.

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The pulsing I had heard is common with an overload so I took to the PCB with the ohm meter and checked the capacitors, not one but 2 had a direct short, both the same cap, C25 & C27 1000uf 25v. I will do a blanket change of caps before I try this unit again, I am missing 2 caps from what I have in stock so it will have to wait till next week. So thats 3 items for repair I have waiting for parts, reminds me of running a repair shop again !

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roberttx
January 8th, 2017, 06:43 AM
Very nice, congratulations!


... it had been shipped with polystyrene around it but I was lucky and landed in perfect condition...

Out of interest, what's the problem with expanded polystyrene (or Styrofoam)? Many people consider it a very useful cushioning material for heavier, denser items.

mikey99
January 8th, 2017, 07:52 AM
For 5154's its a good idea to replace all the electrolytic capacitors in the power supply.
Looking at your pictures it appears some of the capacitors may have already been replaced.

It may also be a good idea to replace the mains X2 capacitors as these are known for
blowing and causing a lot of smoke.

EDIT: The attached picture shows one PS I repaired awhile back, some of the capacitors look different, that's why
I mentioned some of yours appear to have been replaced.

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Flamin Joe
January 8th, 2017, 05:28 PM
If there isn't one already, would it be possible to do up a parts list for which capacitors are needed for a full replacement? I also have a 5154 which from quick testing appears to be in fully working condition but I was contemplating a full recap anyway just to be on the safe side.

Great to see another fine machine slowly getting back up and running. :)

lutiana
January 8th, 2017, 05:45 PM
If there isn't one already, would it be possible to do up a parts list for which capacitors are needed for a full replacement? I also have a 5154 which from quick testing appears to be in fully working condition but I was contemplating a full recap anyway just to be on the safe side.

Great to see another fine machine slowly getting back up and running. :)

I second that, as I'd like to recap my 5154 as well. It'd be nice to have a list of needed caps to order before I take the thing apart.

offensive_Jerk
January 8th, 2017, 06:49 PM
If there isn't one already, would it be possible to do up a parts list for which capacitors are needed for a full replacement? I also have a 5154 which from quick testing appears to be in fully working condition but I was contemplating a full recap anyway just to be on the safe side.

Great to see another fine machine slowly getting back up and running. :)

That would be amazing. I would also like to recap my 5154.

Malc
January 8th, 2017, 10:42 PM
I second that, as I'd like to recap my 5154 as well. It'd be nice to have a list of needed caps to order before I take the thing apart.


That would be amazing. I would also like to recap my 5154.

Be aware Clint's 5154 has a Model Number of 5154002, I believe the 5154 had Model numbers of 5154 / 5154001 / 5154002 / 5154003 as the 5153 did. The 5154 being the 120V model only. So probably best to check your own PSU's.

Clint
January 9th, 2017, 01:06 AM
If you have a picture of your PSU can you post it along with the Model Number.

The PSU posted above by Mikey 99 looks identical to mine, what is that from ? and what voltage ?

If anyone is in the UK and wants a set of Panasonic EE, FC & X2 caps I can do 2 sets at cost from Farnell.

I will make a full list as I go through the monitor.

Malc
January 9th, 2017, 04:03 AM
If you have a picture of your PSU can you post it along with the Model Number.
I don't have any pictures, It's been a long time since i re-capped the PSU in my 5154002


The PSU posted above by Mikey 99 looks identical to mine, what is that from ? and what voltage ?
Looks similar, I'd guess a 120V model ?

I also seem to remember having seen at least 2 different manufactures of PSU, But it's been so long i can't remember what model, 5153 or 5154.

mikey99
January 9th, 2017, 06:15 AM
My 5154 is a 120V model. I have several ...... and I think they are all 5154001

Clint
January 9th, 2017, 06:42 AM
My 5154 is a 120V model. I have several ...... and I think they are all 5154001

Can I get a look at the PSU - wonder if its a completely different PSU or just some modifications ?

Malc
January 9th, 2017, 06:45 AM
That makes sense, IIRC both the 5153 and 5153001 were 120V and the 5153002 / 5153003 were 120 - 240V models, My 5154002 has a voltage rating of 200 - 240V unlike my 5153002 so unlikely to work on 120V.


My 5154 is a 120V model. I have several ...... and I think they are all 5154001

mikey99
January 9th, 2017, 07:47 AM
A few more pictures:

Clint
January 9th, 2017, 07:55 AM
A few more pictures:

That looks the same as mine, Ill try mine down at 110v with my variac when I get the new caps in place.

Looks like you have a dodgy cap there, the small 47uF?? I think.

Malc
January 9th, 2017, 08:31 AM
Though it looks similar you need to compare solder side to yours really, Yours may have different tracing in places and a few higher rated components.

Clint
January 9th, 2017, 08:54 AM
A few more pictures:

Had a quick look, so basically all the PSU's rectifiers work as a voltage doubler, which is bypassed by the link I have circled in this photo.

So the power supplies are the same UK and US :)

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paul
January 9th, 2017, 10:40 AM
A few more pictures:

Note that one inductor at the left is missing half its core.

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Clint
January 9th, 2017, 10:48 AM
Note that one inductor at the left is missing half its core.

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Yes thats fallen off at some stage.

mikey99
January 9th, 2017, 12:04 PM
The PS in the attached pictures came from a 5154 that had blown one of the X2 capacitors, lots of fire/smoke was released :-)
Notice all the black crud around the X2 capacitor by the inductor. Its possible that inductor core fell out as a result.
Can't recall if I put that core back in but I probably did....or I may have used a PS taken from another 5154 in that one.

Shadow Lord
January 9th, 2017, 05:07 PM
Hello All,

How easy is it to drill the rivets out? I have a FEW 5154s/7534s and even a coveted 5175 that need/will need the PSUs looked at... I am wondering if the PSUs were the same across the monitor models (at least between the 5153, 5154, and 5175)? Would make it much easier to order caps in bulk ;).

mikey99
January 9th, 2017, 05:15 PM
I think the 5154 PS is not the same as the 5153. It's been awhile since I opened a 5153 but I think the
PS may be on the mainboard. On the 5154 the rivets are very easy to drill out, and replaced with a few
sheet metal screws for re-assembly. I also have a 5175 but have never opened that monitor. Which reminds
me I should pull that 5175 out and power it on more often ! Probably been a year or more since I did that.

EDIT: Checked the SAMS for 5153 and found that there is a separate 1) AC Input and 2) Power boards
but they are totally different than the 5154

Shadow Lord
January 9th, 2017, 05:30 PM
EDIT: Checked the SAMS for 5153 and found that there is a separate 1) AC Input and 2) Power boards
but they are totally different than the 5154

Of course, why would it ever be easy? :D

roberttx
January 9th, 2017, 09:14 PM
Last time I opened a 5150 psu (early '90s and not to recap it) they were held together with so-called "security" Torx head screws.

Back then, I used to chisel the central pin out and use a regular (T8 or T10, iirc) driver. Today, Harbor Freight (or Argos) will sell you a suitable bit set for knack all.

lutiana
January 10th, 2017, 06:59 AM
Last time I opened a 5150 psu (early '90s and not to recap it) they were held together with so-called "security" Torx head screws.

I found the same to be true on the PSU in the 5162 and on the PSU in the 5170 I have. Both also had rivets in place of one or two screws. Interestingly enough, the screws on the 5145 monitor were also security torx.

For a company that published docs that could help you clone these things with near perfect precision, they really did not want you to open up some of their stuff...

Shadow Lord
January 10th, 2017, 08:14 AM
For a company that published docs that could help you clone these things with near perfect precision, they really did not want you to open up some of their stuff...

I think they really did not want just anybody opening their stuff. The guy who spent a few hundred dollars buying TR and HMH books probably knew how to deal with security screws and rivets.

Clint
January 10th, 2017, 01:18 PM
All done, its amazing how small modern caps are I went for a mix of Panasonic EE and FC series capacitors.

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I tested all the caps that come out, the ones on the left (plus the RIFA's) are out of spec, 1 is short, 1 is 10% and one 50%, the ones on the right are frightfully on spec, like nearly all of them +-1% I could not believe it, most new caps are not that close.

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paul
January 10th, 2017, 01:50 PM
It seems the smoothing caps on the outputs get the most stress. I still have all the original electrolytic caps throughout on my 5150s and 5170 but the X2 and Y2 have been unreliable at 240VAC.

Malc
January 10th, 2017, 10:12 PM
Not done bad for their age though, My original later model 5150 PSU has had nothing done except for a check and dust out when i got it, My 5160 PSU's have had the same and the X2 Rifa's replaced with better quality and new fan's in a couple, My XT 286 PSU has had nothing done but a check and dust out, My 5170 PSU fell ill several months ago and died a couple of days later, I'm pretty sure it's just cap failure but haven't gotten round to looking at it yet.

Clint
January 11th, 2017, 01:26 AM
I think the RIFA's have done great, these things are 30+ years old its a cap that goes directly across the mains. I think the thing is its the first thing to go wrong so they get a bad rep, they also make a mess like a little kid with a bucket of lego and jam.

Modern RIFA's are much better, however a lot of people are putting new ones in and they are failing, I am pretty sure these are old stock, I will only use ones I buy direct from a distributor. The interesting thing is an old stock part gets much warmer than a new stock part even after a few minutes, so although they look the same there must be some significant changes in manufacturing.

I do quite a few repairs for people and do get people requesting original parts or at least original looking parts, so I use RIFA's (new traceable stock) and I have never had a problem, if they had gone wrong all my customers would have come back to me.

I also do like the Panasonic series of Black suppression caps, which I have used here, anything up to 0.068uF are classed X2/Y2 so you can keep the range in stock and cover both the X and Y suppression needs.

Anyway, I have found some screw that I think will work so am going to test some of the caps in the rest of the screen and if ok I will put the screen back together today and test.

Clint
January 14th, 2017, 11:55 AM
I got around to putting the screen back together today, I went though the rest of the screen electronics and all looked great, one thing I did spot was these 2 caps on the RGB drives, they looked a bit swollen but it seems that they were perfect electronically, it was just the plastic labels had shrunk with the heat:

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I then got around to trying it all out only to realise that although I brought it all together apparently from a display, it would seem it was simply that as the base unit had a MDA card so not compatible.

So I am on the look out for an EGA card has anyone in the UK got one they would like to sell me ?

I also have this Expansion card, does anyone have any information on it ?

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mikey99
January 14th, 2017, 12:20 PM
The 5154 should also work (a bit blurry) attached to a CGA card.

Also, when powering a 5154 on not attached to a video card, you should see a white raster.


Glad to hear that the other capacitors were okay. I've often thought about changing all the capacitors
in a 5154, but may not be necessary because only the PS seems to run very hot.

Clint
January 14th, 2017, 02:12 PM
The 5154 should also work (a bit blurry) attached to a CGA card.

Its not a CGA card its an MDA - I have the raster but it does not work with the card :(

modem7
January 14th, 2017, 02:30 PM
So I am on the look out for an EGA card has anyone in the UK got one they would like to sell me ?
Readers may like confirmation that any brand will do, rather than just IBM.

Also, the minimum amount of video RAM that is acceptable to you. Depending on what you are doing, you may require 256 KB. See [here (http://minuszerodegrees.net/video/ega_64kb_ram.htm)].

Clint
January 15th, 2017, 12:13 AM
Readers may like confirmation that any brand will do, rather than just IBM.

Also, the minimum amount of video RAM that is acceptable to you. Depending on what you are doing, you may require 256 KB. See [here (http://minuszerodegrees.net/video/ega_64kb_ram.htm)].

Good point, I actually don't care much, I just want to get the 5160 working with the 5154 :)

Clint
January 23rd, 2017, 01:16 PM
I purchased a Quadram EGA card from eBay and fitted it this morning only to be presented with the same issue, after getting some help on here and checking the dip switches it was apparent I had a screen issue.

I took the screen back apart, it was sold to me as faulty and had the PSU failure above, so I found it hard to believe it also had a input issue, I was greeted with a disconnected input cable, my fault :)

After reconnecting I now have a fully working PC, the HDD works as does the floppy drive.

It has Lotus 123, Supercalc and Word Perfect (2 versions) installed and looks like it was last used in 1998.

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Just got to find some more information on the STB ram card that is installed and I can wrap this repair up :)