EZ Trak DX

[Flying A]

I'm completely new to this brilliant site, I stumbled upon it whilst trying to solve a problem with my Bridgeport EZ Trak DX.
I've had the machine since new and not had a problem with it, however this morning when I turned it on although I had power to the main spindle and coolant pump I found the display was blank and there was no power to the servo motors.
I opened the back panel and noticed there were two red lights showing on the long board that plugs in to the Mother Board, I'm not sure what this board does.
I'm thinking it could maybe be a problem with this or the MB or even maybe the power supply.
Any advice would be appreciated before I have to call out the expensive bridgeport Service Guy.

thanks
Ray

[machintek]

That is the BMDC which actually runs the machine and has its own processor and memory. When you LOAD a program it goes to this board. The red lights meanthat the software has not loaded
Press the rest button, and see if the floppy turns on for a few seconds.
Trying to figure out if the mother board is dead. If the floppy lights up then the MB is working.
Is the fan turning on the logic power supply?
Look at the MB in the area where the keyboard plugs in. Any corrosion?

George

[Flying A]

Thanks for your reply, the fan on the power supply is working so all ok there, when I press reset button the floppy doesn't light up.
Took the plunge and took the mother board out to get a better look at it, there a small amount of corrosion around the cmos battery pack ( it's the old non replaceable type).
Do you think maybe the motherboard is dead?
If so finding a 486sx is going to be fun.
Any thing special I should look out for?

Thanks again for your help.

Ray

[machintek]

Sounds like the mother board may be dead.
Dumpster diving, thrift stores, etc are good sources for 486 but be careful as they will be old. The battery is replaceable. You need a soldering iron. But corrosion does not make for a good mother board. Remember that it needs a ISA slot for the BMDC board. Most MB that Bridgeport used were 133Mhz or slower

George

George

[Flying A]

George,
Thanks for your help so far, I bought a 486 Motherboard off Ebay from a reputable source, it was a lot longer than my original (about the length of the BMDC board) managed to get everything back in the right place but the machine is just the same as before.
One thing I noticed is there was no place for a CMOS battery on this board??
Would that make a difference also I couldn't refit the reset button wires anywhere.
When you plug the various cards and boards into the ISA slots does it matter where they plug in?
If its not the MB is it then likely to be the BMDC board?

Thanks for your help.

Ray

[Flying A]

Thought I would post the solution to my EZ Trak problem. After replacing the MB and the power supply I decided to plug a PC monitor into my machine just in case it was the screen that died.
Hey presto, it was the screen all along, the reason for no apparent power to the control was due to the cmos battery being dead, therefore the machine wasn't booting up but because the display wasn't working.
Frustrating conicidence, now I need to replace the cmos battery, but it's the soldered in type, is this replaceable or should I fit a board with a replacable battery.
Thanks

Ray

[machintek]

I purchase these NiCad batteries at a local electronics supply house. I use a solder sucker to unsolder the old battery. I use a Weller temperature controlled soldering iron as to not overheat the board. The battery has to be removed. Otherwise it will leak and ruin the motherboard. You could also use a external lithium battery if you had the book on the motherboard to see where to attach it and which jumper to move from internal to external.

George