TM504 backplane repair

Colin Herbert

I have a TM504 where contact B22 on the high-power compartment connector has got mangled. It can be seen that it is sitting badly and maybe shorting to A22. I know that this connector isn't used very frequently, but I was hoping to use my PS503A in that compartment to take advantage of the 1A output. I have obtained a brand-new connector (#131-1078-00) and was hoping to be able to use it to effect a repair. I think I have a number of options:

a) Unsolder the entire faulty connector and replace it with the new one - this looks like a formidable task, since there are a total of 56 pins to unsolder and re-solder and access isn't straightforward but it would be the most ideal option, I think. Unfortunately I don't have a de-soldering tool, only a solder-sucker and some poor de-soldering braid (I suppose I could buy a de-soldering tool).

b) Somehow remove the faulty contact and replace it with a good one from the new connector. This would be fine, but it doesn't look easy because of the way the contacts are secured in the new connector, they are not easy to remove as they are retained by way of a punched indentation which has resulted in a raised "dot" on the other side. I have tried crushing this down, but it isn't easy. If the mangled contact in the existing connector is retained in the same manner, I can't see how removal can be managed.

c) Just remove the mangled contact by "brute force and ignorance" and forget about its function for the PS503A (it is -V output) . This wouldn't be ideal but would probably be functional, even though it would irritate me as being imperfect.

d) disconnect the electrical connection to the faulty contact on the TM504. I don't like this idea at all.

e) disconnect the electrical contact on the PS503A. I like this option even less than (d).

Does anyone have any experience of doing such a repair or any other/better ideas?

TIA, Colin.

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