Need Help!- Another 10TF problem

[mrwhittle]

I have a Mori-Seiki that hasn't been used in about a year and a half. I have been powering it up and cycling it every couple months, but this last time
I let it go for about 3 1/2 months (my bad). Now when I turn the power on
the hydraulics come on, but when I push the power on button the control doesn't
come on. The CRT is black, no warnings, nothing at all. I can hear a
contactor/starter pull in when I press the power on button, but nothing happens. I tried holding the OT release button in while pressing the power on button and that's not it. I would appreciate any and all help.

Thanks,
Martin

[tc429]

door interlock open?
somebody 'borrow' parts?

see if the green 'pil' lamp on the input unit goes out/and the red led comes on...if the green lights staying on, and the contactors not clicking on, check resistance across your 'off' button contacts. Ive had a lot of these start showing their age lately, sometimes just hitting the button a dozen times will clean the contacts, more often than not gotta replace/at least clean the contacts.
if the red light on the input unit comes on, theres a 24 volt short somewhere, check ohms from ground to +24, if its like a couple ohms or less, start pulling +24 wires one at a time till ohms increse, see where it goes...usually x/y switches corrode if its been sitting, but could be anywhere. a failed power supply not sending back the ok signal (tink the signals called pa/pb in the diagrams, 2 of the wires from the little black 5 wire plug on the input unit) will cause the red light too, but more often than not its a 24v short, always fun to find.

[mrwhittle]

tc429

I appreciate your help!! Please bear with me, I'm not an electronics person,
but I'm pretty good at following directions (for an old coot).
Door interlock is set correctly.
No parts robbed.
Barfeed set correctly.
I put the meter on the off button, and it checks good.
When I press the power on button, the green 'pil' on input pcb (A16B-1200-0800) comes on and stays on.
The contactor tagged MCC pulls in and latches.
Any further thoughts?

Thanks,
Martin

[tc429]

hmm...thinking while typing...and not very good at either, just tossing some ideas out there Im not a electronics person either, just a tinkerer that has had fun retrofitting Fanuc stuff since '84, and dabbling in trying to fix some stuff once in a while...

anyway, look at the back of the CRT- is the tip of the tube glowing? if not (assuming yove got the 9" CRT) theres a little power supply card piggybacked behind the keyboard- weve had a LOT of those fail, theres a couple little fuses on there, but Ive never seen them blow without also blowing the switching section. I had a hard time finding some of the components, usually just sent them out for repairs

if thats OK, actually first- set your interlocks and have someone hit the button while watching the little LED on the master- if its doing nothing, possibly no power coming into the black power supply on the master board- theres a couple fuses on there, normally though I think if they blow the pa/pb wont go back to the input unit and the red light comes on- hopefully someone else can chime in/verify.
I know in the zero series, theres one capacitor that usually goes taking out the supply, think its C17? taking the covers off the supply you can do a quick ohm check on the caps- if one of the aluminum ended capacitors looks ballooned and/or checks shorted, they are pretty easy to find/replace- usually (hopefully) the rest of the supply is fine. the big (like over a inch) caps Ive never seen fail, the plastic ends often look puffy, but thats kinda normal for those...often the smaller ones will actually split that little 'Y' in the aluminum end if they short, sometimes leaking a little black goo out too.

other than that, cant really think of much else to watch for- assuming all the fuses have been looked at, if your not familiar with the little goofy fuses Fanuc uses, theres a lot of little green ones(on the power supplies/one on the bottom of the I/O card on the master(if it has that style) or some on the wider i/o card with the 50 pin plugs...all those have a little white indicator that shows in the hole if they blow- I think the supply behind the CRT used the big black or brown fuses- similar to the green ones, but about 5 times bigger- again look for white flags showing in the hole to see if they blew.

Mori probably has another big 24 volt supply somewhere, youll need drawings to see what/where to check, but that shouldnt keep the cnc from trying to boot- at least thru SOME of the LED number countdown on the master board...hopefully you'll see SOMETHING on that display momentarily- whatever it shows is listed in the maintenance manual...good luck

[tc429]

DOH, just reread/noticed 10T-F...so you have a big color monitor. the 14" color monitors weve had were kinda notorious for flyback transformers going bad- if checking around the CRT stay way clear of that flyback secondary lead- Ive seen a couple with voltage so high the whole wire glows like a flourescent tube- actually thought someone put a light in a cabinet once till I smelled that ozone/burning smell...some TV guys I knew warned me about never touching one as the tube can have enough capacitance to store a dangerous charge
if your CRT flyback fried, the back end might still glow- yet no display- but you should definitely see a display number on the master board. most of those troublesome flybacks had brightness pots built in the transformers- sometimes just a scratchy pot, you can mark/turn back and forth a little to see if you get anything.
the 14" color used signals compatible to the common -092 9" mono used on a zero-c (no idea why the hi-res green monitors have RGB, but they do), in a pinch a couple times we put 9" monos back in the big 14" frame just to run the machine- but very hard to see...especially the softkey tags

[mrwhittle]

tc429

You jogged my memory about the monitor. I had it replaced seven years back. I took it to an old TV man and he seemed to think the flyback transformer was bad, but we couldn't find the right one. I ended up replacing the complete unit.

When the flyback goes bad, does it normally do damage to the monitor pcb?

I've started checking fuses, but haven't checked them all yet.

Thanks
Martin

[mrwhittle]

Well, this doesn't sound good. The 7-segment LED on the master PCB is reading the number 6, which is "RAM check error". Countermeasure is "Replace master PCB or ROM/RAM board additional memory board".
Could the PMC ROM cassette cause this alarm, and is there anything else I can check, or is it time to replace the master PCB?

Thanks,
Martin

[tc429]

I dont have a book here...I think theres a ram test available thru IPL mode- hold minus and period at bootup and see if a ram test option exists...been a long time.

I think a power supply issue *might* cause some boot errors too, seem to recall a noisy 5 volts or missing 15 causing odd stuff too- I think theres test pins for the supply right on the master- on the zeroes they are kinda hard to see as they put them under the supply...

got a bunch of runnin around to do, I'll see if I can find more info- hopefully someone else will chime in first

before ordering a board, first verify for certain supply is not a problem, THEN worst case all-clear and try to reload...all-clear is a last resort- gotta lot of important stuff to reload, stuff most folks cant find...options(full parameter listing), PMC data/keep/counter/timer stuff...with any of it missing it can be fun to recover
Tim

edit- just recalled you said it sat-leave power on and open the 3 cell battery box- if its corroded, thats what caused your ram parity error- will NEED to all clear and reload- but boards fine. PMC cassette will give a different error...hopefully your batteries just died or corroded. if not corroded, check dc volts on the back of the box, shiould be 4.5 volts- I think memory will hold close to 3~3.5, but at that low they are dead.