main board repair - surveying instrument.

mickdw

I have a pentax total station which is a surveying instrument that has capability to accurately measure angles together with laser distance measuring etc.
It also has some processing ability so it's is quite a useful bit of kit in the land surveying / building business.
Now it suddenly failed to power on. I took it back to retailer / service centre who informed me that the main board was gone and that parts were no longer available and basically handed it back to me. It's about 12 years old.
I wondering if someone here that is good with electronic boards would be interested in going through it.
It's simply not powering on.
I've been looking for damaged machines as they occasionally get broken on building sites and while much of the delicate measuring equipment can be destroyed, the main boards would generally be fine. I've failed to find one suitable so far so
Any ideas?
Anyone want a challenge?
Any electronics students want to have a look?
I will pay a reasonable fee.

brightspark

Try

http://www.lektronix.ie

mickdw

brightspark wrote: »

Try

http://www.lektronix.ie

Thanks,

I contacted them. Have not heard back.
Thinking of sticking up a note on a college notice board.

DublinDilbert

Failure to power on could be something really simple. I would doubt that the parts are completely not available, there's probably equivalent parts available.

Can you post some pics of the main board, both sides and i'll have a look on here.

Many service places don't want to touch something which they don't have a spare board to swap in/out of it.

mickdw

DublinDilbert wrote: »

Failure to power on could be something really simple. I would doubt that the parts are completely not available, there's probably equivalent parts available.

Can you post some pics of the main board, both sides and i'll have a look on here.

Many service places don't want to touch something which they don't have a spare board to swap in/out of it.

Thats it exactly. Service guy was only interested in fitted a new board. As that was not available, he just handed it back.
No doubt someone who could work their way through the board could fix it.
At least he confirmed it's the main board as he told me he swapped it into another machine.
I will take the board out and get some pictures over the weekend.

bonzodog2

http://www.ebay.ie/itm/Pentax-PCS-225-PCS-215-Total-Station-Survey-Tool-Spares-Or-Repairs-/390954665531?pt=LH_DefaultDomain_3&hash=item5b06b6c63b for spares, asking 350GBP :eek:

mickdw

bonzodog2 wrote: »

http://www.ebay.ie/itm/Pentax-PCS-225-PCS-215-Total-Station-Survey-Tool-Spares-Or-Repairs-/390954665531?pt=LH_DefaultDomain_3&hash=item5b06b6c63b for spares, asking 350GBP :eek:

Yes. I have been looking on ebay for broken ones as they can often get knocked over on site but would still be switching on. That is not my model though. Mine would be a bit more modern I'd say.

whizbang

Can yo post a pic of the board? It would be a good indicator of the difficulty of the job. Any water damage?

mickdw

whizbang wrote: »

Can yo post a pic of the board? It would be a good indicator of the difficulty of the job. Any water damage?

Well post pic today.

mickdw

Photos of front and back of main board

whizbang

I think i'll pass on that one... too much custom stuff.

Is there a rubber keypad for power on ?
if so try removing and cleaning the pads, also swap a rubber from another key.

Did you google any part numbers from the board. There looks like one in the upper half center of component side.

Look hard at the bigger components connections. Top left of the component side is a heavy inductor, most likely to break off in a fall.

mickdw

whizbang wrote: »

I think i'll pass on that one... too much custom stuff.

Is there a rubber keypad for power on ?
if so try removing and cleaning the pads, also swap a rubber from another key.

Did you google any part numbers from the board. There looks like one in the upper half center of component side.

Look hard at the bigger components connections. Top left of the component side is a heavy inductor, most likely to break off in a fall.

There are 2 screens and control buttons- duplicated on each side. Both rubber on off buttons have same effect. Makes a tiny click which was always start of the startup process but goes no further.
This machine didn't suffer a fall. Was using it. Switched it off, moved it. Then no switch on.
I have Googled most numbers I could find in it and didn't show up much of interest.
I was thinking of putting a notice up in university for electronics student to try to fix it.
Would that be a Plan? Don't know anyone else who might be able to look at it. Any companies I've contacted have not answered.

DublinDilbert

I wouldn't let a university student near that instrument.

First port of call would be to get access to a microscope and inspect every solder joint on the board. If you can get access to a microscope get a good magnifying glass + desk lamp. If you can get it under a microscope, gently push on the smt components legs to see if any move.

I would guess its probably some cracked solder, check around the screw holes in the PCB as when its screwed down the board can flex and damage the solder/components around them.

Also check the solder around the legs of the through hole large components + connectors, often you get a crack around one of these components, very hard to spot without magnification.

I'd normally offer to have a look, but i know i'll be flat out for the next month or so.

bonzodog2

Maybe http://electronicpartner.ie/contact-us/ might be able to help you

mickdw

bonzodog2 wrote: »

Maybe http://electronicpartner.ie/contact-us/ might be able to help you

Thanks
I filled in their contact form. Will see what they say.

nibble

Not really adding anything here but anyway; it's pretty much entirely all IC's so it's going to be relatively difficult to say any particular component is faulty without knowing a lot of the details and various electrical properties of the board and IC's themselves.

Double check for loose connections, broken solder joints as others have said. It's a fairly niche product (compared to an iPhone at least) that is a few years old and has been probably superseded multiple times hence, you won't get too many willing/able to repair it.

Without someone that happens to know a lot about these particular devices I'd say you're probably SOL.

mickdw

Given that it fails to actually power up at all, would it follow that the fault is early in the system or is that a totally stupid statement.
I mean could someone with knowledge follow the power source from battery through switch etc and possibly find a broken joint more quickly that way without getting super technical with it.
I dont believe its common for these machines to do this. They are well known for throwing faults on screen and failing to actually function but no power at all is usual Im told.

DublinDilbert

mickdw wrote: »

Given that it fails to actually power up at all, would it follow that the fault is early in the system or is that a totally stupid statement.
I mean could someone with knowledge follow the power source from battery through switch etc and possibly find a broken joint more quickly that way without getting super technical with it.
I dont believe its common for these machines to do this. They are well known for throwing faults on screen and failing to actually function but no power at all is usual Im told.

Do you have access to an oscilloscope?

If you can't find anything visually, see if you get a clock signal on the crystal supplying the main clock to the CPU.

Its should be easier to find a problem with an instrument that doesn't power up at all, rather than one that has an intermittent fault.

Does this have a battery pack & mains adapter connector? there might be a problem with the change over contacts in the barrel jack plug.

mickdw

DublinDilbert wrote: »

Do you have access to an oscilloscope?

If you can't find anything visually, see if you get a clock signal on the crystal supplying the main clock to the CPU.

Its should be easier to find a problem with an instrument that doesn't power up at all, rather than one that has an intermittent fault.

Does this have a battery pack & mains adapter connector? there might be a problem with the change over contacts in the barrel jack plug.

No. No mains power, just battery pack that is charged separately.
Have no clue about clock signal etc.
Fancy having a look yourself?

CountyHurler

If there's no power to it at all, I would start from the input AC with my multimeter and work my way in ... Could be something simple.. I had a power supply for an electronic screwdriver last week, and one of the windings on the first inductor after the AC input pins on the circuit had broken off.....

However, if you find that the voltages going to the main board look right, I would probably back off at that stage..