CF-29 MK5 Not Powering

I've had no problems with my CF-29 until this last weekend...

I keep the computer on my sail boat and the salty water of the Chesapeake Bay is not the easiest environment for any equipment, but this toughbook has done remarkably well for the past 3 years. Two weeks ago I noticed that the battery charger wasn't reliably working, but all that I needed to do was fidget with the plug and the charge light would come on and everything would work as normal. I chalked it up to a bad plug and promised myself to get a new DC charger over the winter.

Last week however, I could not get the device to power on at all. No POST test, no BIOS, no blinking LEDs, no flicker of the LCD, absolutely nothing. I took the device home and was able to charge the laptop (AC charger, happy orange LED for a couple of hours, then steady green). The kicker is that I still wasn't able to power the device on. No POST means power to me or a faulty switch. Nothing obvious on the switch so I started to think "blown fuse" caused by the bad poewrsupply plug.

So now I am 3 hours into disassembly and diagnosis and not really having much luck. I have found F2, F4, F5 & F6 but not F3 that is listed in the service manual. I am not sure how to test these fuses though. Is it valid to use the continuity test on my multimeter? When I do, I get the indication that they are still working. Does anyone know where the blasted F3 might be located?

I also discovered some indication that water got into the chassis. There were a couple of corrosion spots where the IO PCB touches the chassis AND it appears that the first and second pin on 8-pin IC next to the F2 fuse are corroded. Right next to that chip another component appears corroded.

I'm at a loss on what to do next. It doesn't look good for this motherboard, but I don't know how to test it for sure. Is there even a market for buying replacement motherboards?

Any advice would be much appreciated.
Thanks,
Buce

 

Place ad ad in the buy sell trade forum here. Post pics of the corrosion.
When you say it won't post, did you try on battery only?
Might be the power plug on the motherboard. I have replaced several in various laptops.

 

I had a bit of trouble getting a good picture of the corrosion, but I thinkthese do a good enough job.


I did try the boot on AC and on battery with the same result--not even a beep or a hum. I don't thinik the plug on the laptop is the issue because i was able to take the battery from an orange charging LED to a full green LED while using the AC charger at my house. That little LED is the only thing that works!

Bruce

 

With the prices of the 29 going down I would just pick up another one and use all your parts. I have seen mother boards go for just as much as a 29 parts machine.

 

I've got an auction site open in another window right now! It would be awful nice to slide my old hardrive into a new box and be done with this project... Especially since I'm not even 100% sure what the issue is!

Bruce

 

Intel DFUP1396ZB Panasonic Toughbook CF 29 Motherboard 1 40GHz Pentium M 1GB | eBay

 

Since you have it open anyway... suggest Google "surface mount fuse images" and then one last look round the boards with a magnifier.

 

If you want a MK5 contact me. I need to pay off the tractor I bought yesterday. Use my web site info@. for phone. The link will take you there.

I think I have a pic of the other fuses if I can find it. Will edit later if I find one.

Thanks,

Jeff

 

when i get water damaged items at my shop i use an ultrasonic cleaner with denatured alcohol