A500+ Problems Agnus Chip?

I have acquired a 500+ (had one many years ago)and get the green screen and 11 flashes & 1 long flash. i have read that one thing to do is remove and clean the agnus chip. I am new to this and have scoured the web for how to this. i have opened up my 500+ but couldn't see an obvious way to do it. i have worked on PCs before but not these

I know this is basic but can anyone give me the idiots guide on how to do this.

[demolition]

You need to use a PLCC puller like this one:

[GadgetUK]

The best option is with a PLCC extractor tool. I think Agnus is U2 - it's the square PLCC package chip. The alternative is check underneath the board to see if there are holes in the PCB (under the chip), using those holes you could very carefully tap the chip out with a blunt jewlers screwdriver, tapping each side alternately until it pops out. That works fine unless someone has used double sided pad / tape to hold the chip into the socket, if they have (like they did on a 500 I fixed recently) you risk damaging the socket.

The final desperate way is again using a jewlers screwdriver and use the 2 slots in the corners of the socket to very gently lever up the chip - alternate each side, and each time put hardly any pressure on or you could break the socket.

If you break the socket i've got plenty if you need one.

[Jope]

The jeweller's screwdriver will definitely crack the socket if the chip hasn't been removed recently via other means.

When it's stuck there properly due to oxidisation, even the plcc puller is a pain to use.

[pandy71]

Originally Posted by Jope

The jeweller's screwdriver will definitely crack the socket if the chip hasn't been removed recently via other means.

When it's stuck there properly due to oxidisation, even the plcc puller is a pain to use.

I agree there 100% warranty that socket will be broken - chip puller is only one solution.

I have ordered a PLCC puller and will see what happens from there. Thanks

[GadgetUK]

Originally Posted by Jope

The jeweller's screwdriver will definitely crack the socket if the chip hasn't been removed recently via other means.

When it's stuck there properly due to oxidisation, even the plcc puller is a pain to use.

It can be done, but you do have to be mega careful. I've done this a few times recently without issue. It depends on how brittle the plastic is, how much leverage you use and patience.

The problem with PLCC extractors is you need a well made one or they just slip off and scratch the chip, and you can end up damaging the socket if you dont pull at the right angle.

[Jope]

The angle must be very very shallow if you're going to try the screwdrivers. :-)

A PLCC puller retracts the claws when you squeeze it, so by definition if you're using it correctly and the claws don't slip, it will pull the chip out straight as the claws retract..