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Removing and Replacing a ROM in a QIKEJECT Chip Socket

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rjarratt

Experienced Member
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Mar 30, 2008
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162
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I want to check the ROMs in my DEC Rainbow so I need to get them out to put them in my programmer. The ROMs appear to be mounted in something called a QIKEJECT chip socket.

The Rainbow Technical Manual and Pocket Service Guide say to push the chip sideways and then lift it. I have tried this but I don't know how much force I can use. It has moved to the right but is not lifting. In the picture below you can see that the first ROM is slightly pushed to the right. Is that far enough?

Furthermore I don't seem to be able to push it back into place either.

Any tips for safe removal and replacement of ROMs in a socket like this?

IMG_20241130_105431.jpg
 
That style of ZIF socket does not age well at all. I ended up having to replace a 64-pin variant after removing a 68000 from one of my Tandy M16B CPU cards. Not a lot of fun on a 4-layer PCB. In your case you may be misreading or misunderstanding the removal instructions. It's not the chip itself that needs to be shifted, rather it's that little tab to the left. IIRC, it's currently in the release position. If that's not enabling the chip to lift, you probably have a broken socket (very common with that style).
 
I managed to get the ROM out. Once it was out the part of the socket that moves springs back into the locked position quite easily. I can easily move it repeatedly to the release position and back to the locked position when the chip is not installed. But when I put the ROM back in it stays stubbornly in the release position and I can't get it back to the locked position. I have a feeling that it may make sufficient contact but I don't know for sure of course. I guess perhaps the pins on the chip are interfering with the mechanism somehow, but I don't know how to get it back to the proper locked position now.
 
I just can't persuade the socket to move into the locked position when the ROM is mounted. I guess I am going to have to remove the socket and solder in a normal socket :-(
 
rjarratt said:
I just can't persuade the socket to move into the locked position when the ROM is mounted. I guess I am going to have to remove the socket and solder in a normal socket :-
Click to expand...
I have been reading this thread and I had never seen a ZIF like that - always ones with a lever. Given that one is not usually changing ROMS frequently on the end product, I don't know why they used that and if they had so little faith in a field tech to change a rom from a normal socket, then use a levered one. Somebody had something in mind, I guess.

Are you going to use a ZIF?
 
I think I have some normal non-ZIF sockets and will use one of those.
 
rjarratt said:
I just can't persuade the socket to move into the locked position when the ROM is mounted. I guess I am going to have to remove the socket and solder in a normal socket :-(
Click to expand...
I don't think it ever moves completely to the locked position when the chip is inserted. Rather, there is (or should be) spring loading that holds it against the pins. If you are not feeling a distinct resistance when moving it to the open position I'd call that socket defective.
 
It did not move back to the position it was in originally not matter what I did. I have replaced it with a regular socket now.
 
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