Anyone ever changed a ROM chip in outboard gear?

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Seeker of Rock

Seeker of Rock

Let us be unburdened by that which has been ?
So I bought the Lexicon LXP-15 and love it. However, from good advice on this forum, I bought an upgrade kit on ebay, on it's way to me. It has the Version 2 chip, a "chip puller", and of course the V2 manual. I have never done anything like this, but hmmm....pulling a chip, how hard can it be? As long as there is no soldering involved, I may be able to do it. Hate to take it to an electronically inclined person if I don't even take a look at what has to be done. Anyone ever done this and do you need experience to do it? :confused:
 
Yes, I have changed many a ROM chip and the like. In particular, the Lexicon units I have worked with have tended to be quite stratighforward.

It's quite simple as long as you take your time and follow directions.
 
usually not a tough job. Crack open the case, grab the chip using the chip puller and out it comes. A couple of little things, first, make sure you are grounded to the unit either with a ground strap or by holding on to the metal of the box when doing the operation (ESD is real and can cause death to chips!) and two, make very sure that all the legs on the new chip line up before making the final seating of the new chip. This is were you can knee over a chip leg and ruin the new chip.
 
Alright, I'm feeling much better about this now. I figured it would be something comparable (in theory, anyway) to a serial computer cable or even an S-video connector with the tiny, sensitive prongs and making sure to align everything before putting pressure on it. Never heard about the static electricity and wouldn't have even thought of it but thanks for the head's up! Kit hasn't arrived yet and I assume the instructions will state this, but the unit should be turned OFF and UNPLUGGED during this procedure, correct? And then by turning the unit back ON, this will "reboot" it.
This sounds like something I can give a try. May come calling if I get myself into trouble or think I'm about to. Love the unit, just want to make it better. :)
 
The instruction guide I had when installing the v2 chip on my Mpx-500 indeed said to turn it off and unplug the source. That should, however, be SOP when tinkering in the guts of ANY electronic unit, inlcluding personal computers.

It also came with a static bracelet meant to ground you when installing the chip (I already had a couple of these though).
 
I'm not hearing any mention of ESD straps. Electro Static Discharge is the #1 killer of integrated circuits.

When I was an engineer at IBM, we had electron scanning microscope photos of the damage inflicted by ESD. Up close, it looks like bomb craters. Very destructive.

Silk panties and styrofoam coffee cups are the biggest ESD generators I've come across so far. Even more than a wool carpet.

If you are asking the question about pulling a ROM chip, it means you have not done so. This is not a put-down, but an observation of fact. Don't destroy your board by being ignorant of Technician 101 working habits. Get a zap strap to prevent ESD damage.
 
That's the static bracelet I just mentioned. Forgot the actual term, but I have been using them for years and years and years.
 
Well, I don't want to destroy my chip by any means, so if I have to get a strap, where can I and, on average, how much do they cost?
btw, call me crazy, but just a/b'd my Midiverb IV and LXP-15. I could get similar sounds on the presets, although the LXP seemed to lend itself to more spatiality. Hmmm...stilll like the verbs (on drum tracks I'm testing these) of both. Not as noticeable of a difference as I may have thought, but I still have untrained ears. I'm learning, though.
Please let me know about the ESD straps/bracelet. Don't want to screw up the Lexi.
Thanks again for the wisdom and heads up. :)
 
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You can probably find one at radio shack, or any computer store, or something like that. I dont think it'd be too expensive.

When I work with things inside my computer, I leave it off yet plugged in, as the case is safety grounded. I dont use a strap, I just touch some metal on the case to g round myself to it, although I do tend to be sloppy with my static protection. Never damaged anything, but it is a real risk with CMOS and other such chips.
 
If you are ordering a Lexicon, their packages come with a strap. As I said, I got a strap with my Lexicon chip.
 
All the advice so far is really good. Strapping to the gear is important, seating the pins properly before pressing down is *extremely* important! Also, try to get the old chips out without bending their pins, as you may wish to put them back in at some later date, for whatever reason. Probalby not, but if they are taken out in working condition they provide a backup to the new chips.

As far as the LXP-15 sounding like a MidiVerb IV, I think you need to give that a bit more time. Listen especially closely to the reverb tails, how they taper off. Is there any flutter or unwanted modulation to them, do they disappear smoothly or can you hear stepping or quantization noise. There are a lot of littel details to listen for in reverb that can be easily overlooked. The lexicon is a classier reverb, and once you spend some time with it exclusively I think you'll notice the difference when you go back ot the Alesis. They both will prove to be useful, I'm sure. Now you can get into layering reverbs, and using different reverbs on different instruments.
 
Alright, the V2 kit came today. No zap strap, but a cool chip puller (looks like a giant tweezer), manual, MKII decal, and of course the eprom. I am going to try grounding this by holding one hand to the unit casing while I work. SHould I also place the casing on my legs while I do this to further ground? Any idea of what surface would be best for my feet to be touching? You have a choice of three...wood floors with urethane laminate, clay tile, or concrete. Don't know if one is more conductive than the other, but though I'd try here first.
Thanks...
 
The best is the strap. Doing it any other way risks the chip. You could go barefoot, and stick one of your toes in the ground hole in a wall outlet, if you wanted an alternative :D

I suppose you could plug it in, grab the chassis to discharge yourself, unplug it without moving your feet, and do the switch without touching anything else.
 
That sounds like the way to go. I was going to ask about that, how to de-staticize myself. Plug in, plug out and keep feet firmly on the ground. I will also be doing this in my birthday suit...maybe Mrs. Seeker will come home right about when I'm doing it!! Actually, it may minimize damage to the IC but increase mental damage to her seeing me au naturale. Oh well, any of the ground surfaces I mentioned above more or less conducive to ESE?
 
Seeker of Rock said:
That sounds like the way to go. I was going to ask about that, how to de-staticize myself. Plug in, plug out and keep feet firmly on the ground. Any of the ground surfaces I mentioned above more or less conducive to ESE?
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Tell you the truth, I'm not sure. I'd say concrete is the best bet, but I'm only guessing. Keeping a hand on the chassis somewhere unpainted is the bare minimum, and I don't know if it works if the unit is unplugged. I usually just use a strap, as keeping a hand on the chassis at all times is a freakin' pain. Someone else might have more info.
 
Always receive good advice on here, so it seems prudent that I would continue to follow. Radio Shack was out (thank God I called first!) but just got back from Best Buy and have one anti-static wrist band in possession. Now I need to do the couple of shots I missed whilst gone, and then I'll be ready to install. Thanks as always for the good advice! I'll post back if I run into any major trouble. :)
 
I think I should have had a couple of more...I was a little shaky, but...SUCCESS!! Sweet, man, a whole new palette of presets to work with and modify. Nice. I think I'll go have another couple in celebration!! A specific plate for drums in V2. I like the "small plate" better out of the box, only because the "drum plate" makes my tracks sound like I'm "boomin'" driving down the street. Obviously a little hot on the lows, but I'll tweak it and turn it into a good drum plate in the user section. Who knows, the "small plate" sounds pretty good as is, a few adjustments needed...maybe I'll just tweak that one too.
Anyway, thanks to everyone for the good advice, as always! :D
A couple of shots now before I play with my toy some more. :p
 
2 more cents

Seeker of Rock said:
Always receive good advice on here, so it seems prudent that I would continue to follow. Radio Shack was out (thank God I called first!) but just got back from Best Buy and have one anti-static wrist band in possession. Now I need to do the couple of shots I missed whilst gone, and then I'll be ready to install. Thanks as always for the good advice! I'll post back if I run into any major trouble. :)
Click to expand...

If this is the first time you have done this:

1. You may be suprised at how well the chip is held in its socket
2. When you start to pull it out you may hear some chrunches and crackles
3. You may want to get a small size screwdriver and slide it under one side
then the other and pry up just a little bit at a time
4. If you try to pull it up with your fingers you may have to put so much
force on it one side may come loose first, it flip over, and punch one of
the legs through your fingers. Won't damage you but does smart.
5. If you do bend one of the legs or collapse it like an accordian it can be
pulled or bent out but be gentle. You can do this about twice, then
they may break.
6. If it has a little lever on the side of the socket, this is a zif socket (zero
insertion force), release the lever and gently pull out.
7 When you unplug the chassis from the wall, you unground it (this
ASSUMES that your socket hase the ground wire hooked up at the
socket, the breaker box and to the ground rod in the ground).
8 What are you hooking the bracelet up to? I leave the chassis plugged
in, power off, and then touch the chassis often during the work. The
chips rarely have more than 10 volts, usually less on them. They will
not shock you, stay away form the power supply though and things
with heat sinks on them near the power supply. If you do hook the
anti stat up to the chassis and the chassis plugged in to gound and the
unit is leaking some power or has a bad ground or your socket is not
grounded (very common in older bldgs) you can get the shit shocked
out of you and not be able to get away till you rip the damned braclet
off.
9. Concrete is good, blue jeans are okay, especially if you used a fabric
softener or dryer sheet. Don't wear a synthetic shirt or polyester
leisure suit, but please wear something.

Last but not least, if it does not work don't blame yourself. Most of the time
this happpens it is doa.

I have been doing this for about 35 yrs and have now found most of the wrong ways to do it.

If you can find a computer savvy kid that is not hyper and has done this before with good results on a computer bios, let him/her do it.

Good luck, but you probably won't need it.
 
never mind

Seeker of Rock said:
I think I should have had a couple of more...I was a little shaky, but...SUCCESS!! Sweet, man, a whole new palette of presets to work with and modify. Nice. I think I'll go have another couple in celebration!! A specific plate for drums in V2. I like the "small plate" better out of the box, only because the "drum plate" makes my tracks sound like I'm "boomin'" driving down the street. Obviously a little hot on the lows, but I'll tweak it and turn it into a good drum plate in the user section. Who knows, the "small plate" sounds pretty good as is, a few adjustments needed...maybe I'll just tweak that one too.
Anyway, thanks to everyone for the good advice, as always! :D
A couple of shots now before I play with my toy some more. :p
Click to expand...

day late
dollar short
 
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