ProLog M980 repair help request

[wepwawet]

Hi,

my M980 died while i tested 4040 CPUs for a member (of course at my fault).
The last error codes were E3 and E4 what means address error and "no personality module installed"
After this the main display is dead while the fan works and (!) the device display of my PM9080 module.

Maybe it wasn't tight fixed while i turned it on sometimes...
I replaced/tested other 4040 CPUs and 4002-1 RAMs.
I deassembled the whole box plus power supply to find eg. a blasted capacitor, nothing.

Does anybody have an idea?

[donutty]

Do you have an oscilloscope? If not.. then you should get one

If you can't fix it and want to sell it... give me a call.

[wepwawet]

Ok, I get an oscilloscope.
Any specification? Or just anyone?
And then?

[wepwawet]

doccy wanted to see some pictures of the mainboard

[donutty]

What oscilloscope you get depends on what you want it to do. You should definitely get a modern oscilloscope (as opposed to a vintage €10 one from a flea market). For example, the one I have (http://www.testmart.com/sp.cfm/ANAOSC/FLU/PM3082-003/1.html) does me just fine (cost second hand about €200).

You can use it to 'see' what signals are occurring. First I would use it to check the voltage at certain points (to make sure everything is getting the power it needs), then the check the clock circuit, data transfer between the CPU, RAM, ROM and peripheral chips etc etc. You can compare up to 4 signals at once on most 'scopes allowing you to see if everything is in sync, a signal changes when something occurs, other parts of the circuit are responding and so on.

You should also get some clip probes (http://cgi.ebay.co.uk/2-Oscilloscope-100MHz-Clip-Probes-Oscope-NEW_W0QQitemZ320255043988QQihZ011QQcategoryZ45008QQtcZphotoQQcmdZViewItemQQ_trksidZp1742.m153.l1262) and maybe even some IC clips (http://www.warwickts.com/product_Model+5228.html)

[Qwerty]

IMHO a logic analyzer would also be very helpful.

Because your ProLog board is quite old you can use an old and inexpensive analyzer. Sometimes they can be found on eBay. Usually they cost less than a digital oscilloscope.

[wepwawet]

thanks so far for all the hints, I'll see what I can get but the conclusion seems to be that almost noone else has that unit and any detailed experience with it.
It is also a bad thing this unit contains all together three boards plus five boards on the personality module....
more than twohundred chips to test:-/

[donutty]

[wepwawet]

learn, that's the point:-)