Soldering Disaster!

I am sure that a blob of solder on a un-powered IC will not destroy it. Because you have difficulty obtaining a replacement card, maybe have a good look at where you remove the solder blob. Try and re-flow the IC with a hot air re-flow gun an some liquid flux that used to repair and re-flow SMD devices. I had very good results re-flowing SMD IC up to 100 pins with a 0,5mm pitch. Good luck.

Ooooh! That sounds way to complicated for me. I do understand what you mean but, unfortunately, there just isn't that sort of expertise available around here!

That doesn't mean I won't try. You have given me the sort of words to use on the phone. Now all I have to do is find the right sort of company!

Many thanks lewisthebear!

Agreed, and there may still be hope. Get a very bright light, magnifying glass and an x-acto knife. Give the board a good going over. Even if there was a short with power on that is not a death sentence with low power digital circuits.

Yes, that is what I thought too! I peeled off as much solder as I could and it was only the solder still attaching to the ram chip legs that was a problem. At this point, I gave up using my own resources and took the unit to a company that could do this work. It was a tech'y there that used the solder braid to remove the solder from between the legs of the ram chip.

AND under a bright light and magnifier, he found that just in a small area, there were what appeared to be some damaged tracks on the PCB which he attempted to repair. He seemed quite confident it would be fine but when I powered it up at home, I found I still had problems with the LCD display.

I am fairly sure that this very small PCB is multi-layered and the damage my not be visible hence my attempt to find a replacement board.

I am also fairly sure that the existing board is all but fixed. It is so very close to working that, I feel that perhaps if I let the tech'y have another go, he would then spot another fault to fix. After all, the devils in the detail.

Not being too electronically adept, the soft option is to find another board but heaven only knows if I could find one anywhere in the world. These data loggers, good as they were, are old and were never thick on the ground.

Hey hughv! Thats a good point! There is a small white sticker on the board that reads:- Nanox NTM113K01 (TLX-1021) Made in Japan.

Stupidly, I never thought to check this out but I will now!

Thanks for that!

Hi Hughv

My original question was "where can I get a replacement part" and, with your invaluable help, I am now on the right path. With the right part No. it's not so hard!

That was well spotted that I hadn't got the part No.! If I could press GA twice I would!

Thanks again!

RAM chips usually have a battery back-up memory supply which keeps the program in memory safe during 'off' periods. If the solder shorted across a couple of pins then the memory is probably corrupted even with the system switched off. Although the RAM should be 'write protected' when normal Vcc is switched off the memory can still be lost when the battery back-up is removed.

If the memory is corrupted you should remove either the battery back-up or the RAM and short out all the RAM pins, (remove the chip and place it on a piece of tin foil). Normally the RAM memory receives it's program from an EPROM or disk during boot-up but needs either a clean or uncorrupted RAM memory to do this properly and you are wasting your time until the RAM is clear. You will probably have to reprogram a couple of operating parameters before the system is back to normal.

RAM chips are pretty robust and I've fitted them the wrong way round before now and they still worked when refitted correctly, but please ensure you guard against static when handling the chip - they don't like static at all!

Hi Tom

Yes, this was what the original task was about....to solder a new bios battery onto the main board! At the time of the disaster, there was no power in the system at all. Since then, I seem to have damaged more than just the ram chip. Apparently, some tracks on the PCB also took a hit!

I just don't think that messing about with it any more is worth the effort when, it now appears, I can buy a new LCD sub-board with attached PCB for a nominal amount.

It also means that the rest of the equipment is less likely to be adversely affect.

It is reassuring to know that ram chips are that robust!

Have you found your LCD?????

Got one for you, bought it to try use it, but can't connec it to PC, would sell for not much

please reply to a380 @ fortin.com

Good Luck

Yes, Thanks mate!

Toshiba Australia had two in stock. I bought one of them and it works ok although, all the characters on the screen are off set to the RHS quite a bit and I can't seem to correct it. It is only a slight irritant.

I'm sure there will be something on the net to help you hook yours up!

Good luck