CF-28 Screen Problems....

So I got this CF-28 in the mail today and it had a bad PCI slot so I took the whole thing apart to swap on a new PCI Module to the main board. Everything went fine, I put it all back together and now the backlight on the screen isnt working?? I can look really close and see the display is working its just not lit up. I took it apart again and checked all the wiring and its plugged in correctly, any ideas on whats going on? And yes I tested it before I took it all apart and the screen was working fine. I'm pissed.....

 

Fuse again!...check F4 on the mbo.


ohlip

 

Any advice for someone who has zero experience with soldering?

 

Just bring it to the one you know who has the ability to do it for you.


ohlip

 

ok so i tried to solder on one from an MK1 mother board and I think I might have burned the fuse a little, I go it on there and it still doesn't work. Now I dont have a good fuse or anything.....very frusterated anybody have an idea what to do next, i really need to get this working!!

 

Ok so I made some progress with this. I did finally get the fuse on there correctly and the screen started working again...well kinda.....I checked with Mega-Man who recently had a similar problem, however he was getting zero display output. My display still works, just the backlight isn't on. When I look really close tho I can see things on the screen. He said it might just be the inverter? What would have caused that to go bad tho? Same thing as what causes the F4 fuse to go bad, taking the screen off with a battery in? Where is the inverter located and how is it changed. I also read this thread http://forum.notebookreview.com/showthread.php?t=198473&page=1 but Im still not clear on if theres other fuses involved in this equation besides the F4 fuse. Also I guess I'll check the bulb also, Im guessing I have to take the screen apart.

 

I doubt VERY seriously if your inverter went bad AND your fuse blew. If your screen was working fine prior to the swap and not after the swap... It is something else. It could be the fuse but in my experience NOTHING works when that fuse is blown. I think you have a bad contact or something not hooked up correctly. You DID have the battery out when you were doing all of this didn't you? Stupid question... I know... But you have to ask them every now and then to make sure.

Was the screen working fine BEFORE the swap?

 

nah I was dumb and had the battery in when I disconnected the screen. Yes I fully tested the machine before I took anything apart and the screen was great. Now only the backlight doesnt work. I checked and double checked the plugs and they are in correctly, any other ideas?

 

Ok new update to this thread, I pulled the screen off and it works just fine on another CF-28, I swapped a known working screen back onto this one and same problem no backlight. so heres where this leaves me. I replaced the F4 fuse, and screen is in working order. I checked all the connecters under the keyboard where the screen plugs in and nothing is wrong. What else would cause the backlight not to work that is part of the board? Ive read that if the f4 fuse is bad it will have zero display output and this is not the case for me theres just no backlight, anyone have any other ideas?

 

I'm not sure you took care of the correct fuse... Can you describe the one you replaced? Was it a small white square one with "63V" on the top? These can be replaced with a small 1A auto fuse and it will fit and work fine... I've fixed several this way. If you were doing all this with the battery in this is probably the culprit...

 

Yeah I replaced the one with the "63V" on it in the F4 slot, I used one off a MK1 CF28 that I had laying around for parts.

 

The F4 fuse is located near the cmos battery connector with the other connector( I think that is mic. connector) as TB said I have a doubt which fuse you worked onto. If the f4 is open(blown) it gives you also a very dim signal on the LCD that is based also on my experience with the CF-28.


ohlip

 

Nah Im sure I have the right fuse. Is there any difference in using an MK1 fuse that would have caused the problem, or is the fuse heat susceptable, I did heat it up a bit when I soldered it on and it discolored at the end a bit. Maybe I ruined it I dunno. Does anyone have a pic of how to jump this using the 1A auto fuse or whatever?

 

Guys I really need a pic of how that auto fuse replacement is done, I really need to get this thing working, can anyone help? Thanks!

 

Connor -

I'd have to suggest that instead of using trial & error to sort this problem, you really should acquire a cheap VOM & learn how to use it (Get a book at the library - Howard Sams has a really good one). This kind of repair is NOT for the uninitiated; if you don't at least have a VOM & the technical knowledge to use it, this kind of repair REALLY is beyond your skill level and you are nearly CERTAIN to wind up burning things beyond repair. This is why other members were recommending you take it to someone who HAS the knowhow; it's really NOT the sort of thing one really wants to try and talk a newbie through.

If you have a Harbor Freight in your town, you can usually pick up a serviceable digital VOM from them for less than $5; otherwise Radio shack has his one:

http://www.radioshack.com/product/i...s=features&currentTab=custRatings&tab=summary

for $20. It's VERY basic; but it will at least let you do this kind of basic troubleshooting. You can also find several good books there on basic troubleshooting techniques.

Good hunting,

mnem
The more I learn, the more I see how little I really know.

 

Thanks but I'd still like a pic of the auto fuse thing if possible

 

Connor -

My point was that if you troubleshoot with a VOM, you will KNOW whether the new fuse you replaced is good or bad or maybe bad solder joint; if it tests good and good connection with the traces then you might have the wrong fuse. You can then test the other fuses on the board (I believe there are 3 or 4 on the CF-28) and maybe find a blown one.

As for the auto fuse thing; I've soldered short pigtails (made from leftover leads clipped from capacitors) on a GMA fuse from Radio Shack to make leads that will reach to the ends of a pico fuse. Don't try to take the fuse off the MB, no need - just piggyback it on the dead fuse. It's easier, it's stronger, and less likely to break traces on the PCB.

Hope that helps,

mnem
"999,999,999,997 electrons... 999,999,999,998 electrons... 999,999,999,999 electrons...Oh crap... dropped them. 1 electron... 2 electrons... 3 electrons..."

 

It does, thanks!