I always rub my fingernail over the notch after I've inserted the chip to verify correct direction.

It's pretty awesome you printed a headstone label for both dead eproms just for that picture.

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http://www.pinitech.com - "Pinball Inspired Technology"

I should blow up a 2732 with reverse voltage and record it. Because where the 5v and ground pins are, plugging backwards directly reverses voltage. They go out with a flash of light from the erase window, no joke....

The larger eproms are layed out a bit differently and do not supernova like 2716 and 2732 do.

Don't ask me how i know.... oops

yes please... i can't be the only one who would watch that 100 times or so...

Also remember that if someone has already replaced the sockets, they may have put the sockets in backwards not knowing there is a notch side.

So if you pull a chip, place a dot on the notched side of the circuit board if the existing socket is in backwards.

I see this all the time when I see bad soldering jobs around sockets.....

I've seen a wire in the erase window glow red and break in a 4 meg in a WPC mpu.

Been there. Done that. Won't do it again!.....good reminder.

i still get caught myself once in awhile. People always complain that the labels are backwards , but in the same machine ie a wpc with dcs the chips face different on the cpu and soundboard , so sometimes i apply labels so the chip is readable , but that means applying the labels differently in the same game . Always look at the notches.

It's not just on EPROMs, either. Every IC has a notch. You can fry any IC by inserting them backwards.

Look for the notch!

Lets see some fireworks!!! sorry if i sound half drunk.. well... derp

BTW, did TI make some shitty EPROMs or do i have bad luck over last few years?

+1

Each time every time. Folks complain that 'the label was on backwards', that like saying your walking of the floor in a space station,,, there is no up, it is all relative to the way the manufacturer did the board. Heck on Williams System 3-7 driver boards, they don't even orient the chips near each other the same way. ALWAYS look for pin 1 and the notch!!!!!!

Always look for the notch... but *COUGH COUGH*, AMI BRAND ICs. Damn, AMI started off bad from the time the printed the label on the package upsidedown... it goes downhill from there when the IC fails later in life.

ALWAYS go by the direction of the notch on the socket and chip.

You have a 50/50 chance and even with those odds its usually wrong.

Step 1, rub original chip looking for notch, step 2 remove chip, step 3 rub new chip for notch, step 4 insert chip, step 5 look for how many legs missed the socket.

Its not you; they suck. Seems like you get a 50/50 chance -- they work in some boards, then not in others.

I like AMD. They seem to work in every board, every time.

thank you kind sir!