HISTORY QUESTION?

LOTTOWINNER

Hi all,
This is a real long shot, I'm trying to repair a IBM 5262 high speed printer, (dot matrix), it's at least 20 years old.
The manuals provided are very good, and also quite detailed, but I was looking for someone that is familiar with this machine, possibly even use one on a day to day basis.

fingers crossed!

Nonmonotonic

OK for a start I dont think the 5262 is a dot matrix printer. Is it this one because if so, its a band or chain printer.

In a previous life I used to work for a printer manufacturing company who was an OEM supplier to all the big computer manufacturers. (Text was king in those days).

Whats the problem, electrical or mechanical. I havent worked on this model but maybe I can assist in a general way.

LOTTOWINNER

Thanks for the reply, you are correct it's a band printer, similar to the clip but not the same.
The problem is electrical, 3 days ago, the printer worked perfectly (inspite of it's age) the only problem was the cooling fan was making a very irratating noise. I sourced a new fan (same p/n as original) and replaced the old fan, before I did this I cleaned the printers pcbs with an air line and vacum cleaner (very carefully) and I would say I was the first person to disturb the dust since the printer was installed.
However, the printer hasn't worked since, on start up it doesn't complete its self check, there is a 2 digit display on the control panel which should stay black under normal circumstances and display error codes in the event of a problem, this however is staying blank. (All the test leds and displays can be checked, none are blown).
I think I must have disturbed something during the operation, I put the old fan back (worth a try!) No luck though.
I have visually checked the area, reseated pcbs and connectors and have not found any obvious faults.
Unfortuately I'm unfamiliar with the printer, and I was SIMPLY asked to replace a cooling fan, which I'm now regretting:).

I know this post is very vague but I thought it would be worth a go.

Nonmonotonic

Remote hardware repair is not that easy but here goes.

These printers are fairly simple and bomb proof so you have to think basic.

First, did you vacuum with the power turned on? If you did there is a possibility of a blown fuse in the power supply circuit.

You say that there is no display, two possibilities ( well two obvious ones! ), no power to display or control lines to display broken/disconnected. Trace cable from display back to card/PCB in printer.

When you say its not completing its self check, is it starting it?

How are the cards in the printer connected ( is there a motherboard, are the hardwire, one single PCB )? You may have dislodged a card and need to reseat it.

Are there any PROMs or the like in sockets that you may have disturbed?

That should keep you busy for a while

Overheal

Nonmonotonic wrote: »

First, did you vacuum with the power turned on? If you did there is a possibility of a blown fuse in the power supply circuit.

ah rofl, I miss the 80s.

Nonmonotonic

Which bit did you miss?

Overheal

the loud screaming ribbon printers and the paper airplanes i would make from them using the airplane wizard in from microsoft office in windows 3.1

those were the effin days my friend.

Nonmonotonic

I assume you are referring to Wordstar and DRDOS.

'Ribbon printers', your a fraud Overheal, you were never around in the '80's!

Fanfold paper did make good fake Christmas trees though ( roll up tightly in a tube shape, cut halfway down at 1" intervals with a scissors then pull up from the centre ). AHHH, Simple pleasures.

LOTTOWINNER

Nonmonotonic wrote: »

Remote hardware repair is not that easy but here goes.

These printers are fairly simple and bomb proof so you have to think basic.

First, did you vacuum with the power turned on? If you did there is a possibility of a blown fuse in the power supply circuit.

You say that there is no display, two possibilities ( well two obvious ones! ), no power to display or control lines to display broken/disconnected. Trace cable from display back to card/PCB in printer.

When you say its not completing its self check, is it starting it?

How are the cards in the printer connected ( is there a motherboard, are the hardwire, one single PCB )? You may have dislodged a card and need to reseat it.

Are there any PROMs or the like in sockets that you may have disturbed?

That should keep you busy for a while

Thanks Nonmonotonic for your time and input, the printer was powered off, during cleaning, (it was actually a plastic nozzle)
I checked the fuses on the power suppy, all 4 were fine.

IT does start the power up sequence but fails to complete (image1), and the display panel is operational,can be verified by holding down test button (image2)

All components are soldered onto the cards (no sockets), image3 shows how the cards are connected with push on connectors.


Something of significance is the power supply pcb (image4) which has a led indicator, will energise on power on, but immediately powers down, possibly a protection feature. This does not effect the control panel/display mentioned earlier.

Nonmonotonic

A few more questions now I see the picture info.

Do any other control panel lights come on during power up?

Where is the power for the control panel coming from?

In picture 3, I notice a card in the top left has ICs with labels, are they socketed or soldered (PROMs often become dislodged if not pressed home fully)?

Are you sure picture 4 is a PSU? I am not sure if thats the complete board but I see no large rectification diodes ( no fuses either ). These babies preceded switching mode PSUs.

Is all the AC stuff working ( fans etc) ?

Any way to get schematics for this machine?


When the printer is powered up and you come to picture 1 is the band turning? Do the start /stop or buffer (or any) buttons have any effect at this stage?

LOTTOWINNER

Nonmonotonic wrote: »

A few more questions now I see the picture info.

Do any other control panel lights come on during power up?

Where is the power for the control panel coming from?

In picture 3, I notice a card in the top left has ICs with labels, are they socketed or soldered (PROMs often become dislodged if not pressed home fully)?

Are you sure picture 4 is a PSU? I am not sure if thats the complete board but I see no large rectification diodes ( no fuses either ). These babies preceded switching mode PSUs.

Is all the AC stuff working ( fans etc) ?

Any way to get schematics for this machine?


When the printer is powered up and you come to picture 1 is the band turning? Do the start /stop or buffer (or any) buttons have any effect at this stage?

On power-up, all leds and 2 digit seven segment display flashes once (self test I think).
Then TEST LED, READY LED AND UNIT CHECK LED LIGHT UP, THEN TEST AND READY STAY ON, UNIT CHECK OFF AND LPI ON, THEN LPI OFF, AND BUFFER PRINT ON, and it stays in this condition. takes about 10 seconds.

The control panel is powered from the digital circuitry side, via a ribbon cable, and not directly from the power supply side.

Regarding pic 3, I believe you are correct, they are PROM's, not in sockets, soldered, I have removed this card and inspected solder joints, looked fine.

Regarding pic 4, the pcb is a power control card, I've included images 5 and 6 to clarify (I hope).

Regarding AC and the fan ! oh yea the fan working!!

The printer's mechanical parts stay completely quiet, nothing makes any attempt to move.

When the display is as shown pic1, I can try and run a diagnostic test, by pressing test button and say for example 6 then 2, it will accept the command but displays a 93 error, which is associated with the card with the PROM's.

I have checked 4 fuses, F1,2,3 and 5, see image 6, haven't located F4 yet? (Hope it exists)

The documentation that I have is very good, and believe it or not I've been working as an electronic technician since 1989, NO really.
As I said, I'm unfamiliar with this type of printer, and as the original fault happened so simply, I was hoping for a simple solution! I should have known better!!!

Nonmonotonic

I see where the rectification is done ( VR1/VR2, top left inage5 ). The reason I enquired about the power board is that there is usually a servo or motor control board to control motors on the printer. You need to trace where the band motor power cable goes. Also there is an interlock switch somewhere which disables the band motor when the band gate is opened (safety reasons). Band should spin so either there is no power to it or it is being disabled.

On the circuit board in the top right position of image3, where do the yellow wires go?

I dont think you have a power problem unless you have just lost whatever voltage powers the band motor.