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Amiga computer related discussion => Amiga Hardware Issues and discussion => Topic started by: Ral-Clan on January 17, 2013, 01:24:09 AM

Title: Need help to remove DMAC chip on A2091
Post by: Ral-Clan on January 17, 2013, 01:24:09 AM

Hi,

I am trying to repair a broken A2091 SCSI card.  I need to remove the DMAC chip, which is a large square chip in a socket (I think it may be PLCC type?).

Here's a picture of the card - it's the square chip:
http://amiga.resource.cx/photos/photos/a2091.jpg

The bugger is in there good.  It's VERY hard to remove and I'm worried I'll break it.  I've tried putting a fine jeweller's screwdriver in the corner slots and gently prying upward, but I'm really afraid it's either going to snap the screwdriver, or break the corners off the socket or chip.  That's how stuck the chip is.

Does anyone know what tool I need to remove this?  I've noticed there are also two holes on the opposide side of the board, under the chip, which show the chip's bottom side.  I don't know if these are meant to insert a tool into to push the chip upward and out.

I've seen lots of chip extraction tools online, but I don't know which one will fit the DMAC chip as I'm not exactly sure what type of chip the DMAC is (PLCC? DIP?)

Has anyone had any experience doing this?  It's like the DENISE chip in size and shape, and I remember taking that one out once - it was also really hard to do.

Thanks for any advice.

Title: Re: Need help to remove DMAC chip on A2091
Post by: psxphill on January 17, 2013, 01:28:42 AM

Quote from: ral-clan;722837

Does anyone know what tool I need to remove this? I've noticed there are also two holes on the opposide side of the board, under the chip, which show the chip's bottom side. I don't know if these are meant to insert a tool into to push the chip upward and out.

It's a PLCC
 
Something like this ought to do it.
 
http://www.ebay.com/itm/PLCC-IC-Chip-Extractor-puller-Removal-Tool-20-to-84-pin-/150609793406
 
Count the pins on the chip and if it's 20 to 84 then it'll probably be fine.
 
Using a screw driver is most likely to crack the socket, which will then not hold the chip in place very well.

Title: Re: Need help to remove DMAC chip on A2091
Post by: CodePoet on January 17, 2013, 01:32:33 AM

Exactly as psxphill suggested, the tool puts pressure on the exterior socket while lifting the PLCC chip itself; do not use a screwdriver!

If you were in Sydney, Australia I'd offer to help out - Canada is the next best place though ;)

Title: Re: Need help to remove DMAC chip on A2091
Post by: Ral-Clan on January 17, 2013, 01:38:24 AM

Thanks,

I ordered that tool off ebay...going to be hard to put this project aside for three weeks waiting for it to arrive, but I'd rather not break the chip.

Title: Re: Need help to remove DMAC chip on A2091
Post by: Matt_H on January 17, 2013, 02:57:50 AM

If there's a RadioShack near you, you can get a PLCC puller from them.