1984 Garrett AM-2 Schematics?

[SVEN1]

Acquired one of these detectors and will not pick up any coins or tune.
Couldn't believe that Garrett ground off all the IC parts numbers on this particular model but, that's what I saw when I opened the box.

Anyone have schematics or a picture with the chip numbers?

[homefire]

I looked for that one some time back and never got any place on it.

I liked the Idea that they run at 50Khz.

[kt315]

Couldn't believe that Garrett ground off all the IC parts numbers on this particular model

it's the rule of Garrett. they sanded off the markings and sealed a part of schematic by black epoxy in alone block (Freedom series, for example).

[homefire]

I thought Minelab was the only ones that did that.

[Melbeta]

It is the "name of the game" in business!!! SECRETS.

Acquired one of these detectors and will not pick up any coins or tune.
Couldn't believe that Garrett ground off all the IC parts numbers on this particular model but, that's what I saw when I opened the box.

Anyone have schematics or a picture with the chip numbers?

I do not have the schematics or the chip numbers, but I can comment on the problem. With Garrett, who does not let out schematics, you have to send the Garretts back for repair. Charles Garrett does government contracts, and is not dumb. I will explain...

Yes, when the manufacturers were making standard parts for sale, the best procedure to make it difficult, if not impossible for reverse engineers to figure out what you had in your design, was to grind the numbers off the chips. At first they covered them with black paint, but you could still either remove the paint or see the part number images through the paint. They also tried to secure them with epoxy.

It was useless to epoxy them into blocks, which they did as well, as we could dissolve away the epoxy with heat guns and pick away at the softened epoxy, and with chemicals it would soften them and we could pick away at the epoxy, until we had exposed the potted parts. Even Whites potted special parts. Different epoxys react differently. They even put fine sand and fine cement into the epoxy, to defeat that method, more trouble, but not impossible. The impossible just takes longer. You use diamond drills and diamond grinding pieces. And face masks for the dust.

The next step in final security was to order a large supply of chips, from manufacturers, with your own proprietary part number on the chips, and without the chip manufacturer's name on the chip at the same time. If you do not have any clues who made them, or what the purpose is for the chips, it is tough. Those are really hard to figure out. Manufacturers will absolutely not give out the proprietary numbers "real world number"! I know, I tried.

I have a machine here, where I can put standard unmarked or ground off numbers of the standard CMOS and TTL chips into it, and it will read them out for me, and tell me their numbers, even if the numbers are removed. But one needs to have them removed from the board, in order to read them out and identify them. I spent around 20 years in the hacking electronics business...That is analog, I quit when it all went digital. Digital is too complex to fool with. Too many variations. We even logged the output data stream of microprocessors and other storage chips, to see what it was broadcasting out in commands to the operating equipment, and figured out what some of the machine code meant. I was one of the top 5 analog cable TV hackers in the world. Alas, I am retired.

I still have some machines (some from Russia and one from China), that will read some of the analog secured EEprom and secured Pic chips contents, not all of them, is designed just for for some secured chips, it jiggles the chips with pulses of volts, to force them to release the contents. Then we would study the binary code after changing it to hex code, and figure out the bytes and figure out each individual bit of the byte code. On some command strings, we would end up with the entire string of command, from the first marker byte to the final checksum string byte. There were ready customers for the knowledge if you could figure it out.

A lot of hacking and cracking of USA chips goes on in Russia and China and illegal clones come out that way from Russia and China. The methods does not work on all chips, some will let you jiggle the contents, others are stubborn and just will not let the contents be jiggled at all, and they are the same chips!
Melbeta
Melbeta

[SVEN1]

Then I must have gotten lucky with my Garrett International S-4 & Gold Hunter, some one forgot to grind off all thr IC chip numbers etc......or what's so special with the AM-2 that needed the Id number ground off?

[homefire]

Yea, thats the first time I heard of Garrett doing that.

None of my detectors are like that.

[Melbeta]

What I said was not specific to Garrett...

Then I must have gotten lucky with my Garrett International S-4 & Gold Hunter, some one forgot to grind off all thr IC chip numbers etc......or what's so special with the AM-2 that needed the Id number ground off?

What I told you, was not specific to just Garrett, what it was specific to was the ENTIRE electronics industry, as I was involved with the electronic industry.

At the time I was a metal detector dealer, I also saw some of the black paint on the chips, potted circuits, ground off chip numbers, and then factory "proprietary numbers". That was the same thing I saw when I quit selling metal detectors and became a surplus electronics equipment dealer.

In 1996, I purchased over 12,000 cable TV converters from the U.S. Air Force Academy, through the surplus sales at Fort Carson, and the units were made by Zenith "specifically for" the USAFA, for the cadats desks, with a special stand that stood over the Zenith Converter, and upon that special stand, stood a Zenith monitor. Inside the boxes, every part had a Zenith "proprietary number". But I had a sheet, with the Zenith proprietary numbers converted over to the "real world numbers"! So go figure....

I have to be fair and honest to say, that this "proprietary number conversion crib sheet" did NOT COME from Zenith! It came from electronic chip hackers.

So, if you have a machine that depicts the numbers, consider yourself lucky.

But as far as why they do it, why they did it on some machines, and not on other machine models, why they did it on some models and on others of the very same models, they are marked, I cannot explain that to anyone. I know you can get schematics from some companys, and no schematics or any information from other companies.

Every Compass detector that I go into, so far, other then one Compass detector, has proprietary numbers!!! But one of them has the real world numbers. Maybe an assembly person, when they ran out of proprietary chips, and had to install real world chips, said "the hell with it all". If you find out, you tell me.
Melbeta

[kt315]

Melbeta, onetime my buddy did present me oldie Zenith monitor. I was very amazed! this SVGA american made had a flat CRT and I believe first SMT components! BTW at the time we used only monitors from Taiwan and Korea, I opened also IBM ones, and all of them were made with rounded CRTs and ordinary details!
thinking your hi-tech has something superior... but not for a publicity...

[kt315]

do you see here Garrett Freedom? not. you see only garrett serfdom

[Melbeta]

The ones I bought....

Melbeta, onetime my buddy did present me oldie Zenith monitor. I was very amazed! this SVGA american made had a flat CRT and I believe first SMT components! BTW at the time we used only monitors from Taiwan and Korea, I opened also IBM ones, and all of them were made with rounded CRTs and ordinary details!
thinking your hi-tech has something superior... but not for a publicity...

The Zenith cable boxes, and the Zenith monitors, were made strictly for the U.S. Government. At least the ones I bought. Since I was not aware of any other Zenith monitors, it is possible that there were other monitors made as well. Those were FANTASTIC monitors! I wish I had some of them today...

You see the Air Force Academy cadets, if they missed a lecture, could sit at their desk in their dormitory room at night, and watch any lectures they missed that day. They could also view other lectures from the day before. All lectures were tapes and sent out as a "in-house" cable TV system. They did not watch local or satellite TV broadcasts, it was all for the cadets convenience in their rooms! Neat huh?

Each room desk was the same, on the right side of the desk was this Zenith cable TV monitor, with the grey plastic stand over it, then the Zenith monitor sat upon that grey plastic stand. Kept things orderly. Each Zenith cable TV box was connected to an coax TV cable coming out of the wall, and they were hooked to the Air Force Academy TV system. They watched only what the Air Force Academy delivered to their rooms. They could watch anytime of day, they could watch and hear a lecture in a room that they could not attend. The Academy made sure they missed nothing! They could watch lectures over and over and over. No wonder they are so smart?

The Zenith monitors were very unique, different from all normal monitors, they had both types of input plugs on the rear, so they would work on VGA or other computers, including the 15 pin and the lesser pin plugs. They also had other types of input plugs on the rear. so you could use them for normal TV stuff. They had brightness and contrast controls, just like a TV monitor, but they worked not only on TV, they worked on computers!!! You could adjust the video up, down, to the left, or to the right. Any kind of computer, as long as it would connect the two different types of plug inputs on the rear to your computer video card. They even could hook up to other type of computers other then IBM type of computers! They even had audio speakers on the monitor for sound. They even had RCA input jacks on the rear. What a deal!

I ran the roof VHF and UHF antenna on the top of my house into them for demostration purposes, and they worked with it too. I used a Zenith Cable TV box in-between the roof antenna and the cable box. Then I also had a Zenith monitor hooked next to it with a computer, and I ran the computer, switched the screen color from amber color, then to green screen, which was what the older computers liked. Then I switched it into a color monitor, and they saw color on the computer.

Man their money came out so fast they got rug burn from whipping the money out of the pants pocket or billfold. And the Zenith monitor, it was flawless video!!!! Better than any monitors I had on my other computers at the time. I never lost one customer. Everyone bought at least one of the Zenith monitors before leaving. Some came back and bought another monitor. And I could have bought around 12,000 of them, and I didn't bid on any but one group of pallets. Did not have enough storage space for all the monitors.

So I know what you mean when you said "AMAZED"! Like I said, I still wish I had saved some of them for today. I do not even have one of them today, but I think I have a copy of the operating manual stored somewhere in the basement.

You could switch them to an amber color screen, or a green color screen, or a white screen for color broadcasts.

So you see, they were really universal type of monitors. I sold them as fast as I had them. I only bought a small amount of them (less then 100 monitors), as my real interest was the 12,000+ cable TV boxes, which were high dollar sales in mail order. I sold the Zenith monitors for $35.00 to $50.00, and some people bought more then one monitor. In a couple of weeks time, I sold each and every Zenith monitor, and regretted not buying the entire stock. I bought them for around $1.00 or less each. Good profit.

The Zenith cable TV boxes I bought them for an average of around 25 to 50 cents each, a few near $1.00 each. They were sold on auctions, on pallets, as lots of pallets. I had to hire a huge flatbed truck with a fork lift just to come and gather up all the boxes and monitors I bought each sales day. I had them stored in three separate warehouses.

I sold the Zenith cable TV boxes from $50 as is, to as high as $250 each with remote control added into the units, and with both RCA outputs and switchable channel 3 or 4 outputs. Those went fast too...But I had a lot of work modifying them at the time. I was putting brand new modulators inside them for convenience.

I still have a bunch of the gray plastic stands, that sat over the top of the cablet TV boxes, and the monitors sat upon that gray plastic stand. I used those right now on some of my computers to raise the monitor up higher so it keeps the monitor at eye level. I was selling those stands for $5.00 each as no computer store had any like it.
Melbeta

[SVEN1]

Seem to have read in one of Garretts catalogs the Am series was the stepping stone to the new Freedom series and they were producing both series at one point at the same time before the Am-2 was phased out. I am guessing the AM-2 might be so similar that if you found out what the AM-2 is made of you might figure out whats inside the Freedoms black box of mystery? SMT parts?

[Melbeta]

You may have found the answer yourself...

Seem to have read in one of Garretts catalogs the Am series was the stepping stone to the new Freedom series and they were producing both series at one point at the same time before the Am-2 was phased out. I am guessing the AM-2 might be so similar that if you found out what the AM-2 is made of you might figure out whats inside the Freedoms black box of mystery? SMT parts?

Things come gradually, so you may have found the reason why they removed some part names and numbers. I have not gone into the Compass Coin Magnum, but some have said in their Coin Magnum was a potted module. Secrecy is important to manufacturers. Melbeta

[SVEN1]

Found the info from a Findmall forum member who has the identical AM-2. But, without the IC's ID numbers being ground off. So I am good to go if they need to be replaced.

I obtained this AM-2 in a non working condition. Found several cracked resistors and a broken one. So just for the sake of it started to replace all the resistors and the 3 electro caps. The Disc and GB pot were also kind of griddy feeling, and a broken meter, those are being replaced also. Hopefully will once again work when finished.

If anyone is interested I will post a pict and the IC numbers

[Qiaozhi]

Found the info from a Findmall forum member who has the identical AM-2. But, without the IC's ID numbers being ground off. So I am good to go if they need to be replaced.

I obtained this AM-2 in a non working condition. Found several cracked resistors and a broken one. So just for the sake of it started to replace all the resistors and the 3 electro caps. The Disc and GB pot were also kind of griddy feeling, and a broken meter, those are being replaced also. Hopefully will once again work when finished.

If anyone is interested I will post a pict and the IC numbers

Yes please. It would be good to add this information to our archives, and it may help someone else in the future with the same problem.