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This is some of the worst Rust Damage I've seen....

F

fallemarg

Experienced Member
Joined
Oct 11, 2010
Messages
133
Location
Olathe, Kansas
Hello everyone. I found a Tandy 1000HX on ebay for a price that I was willing to pay and it was listed as having corroded terminals on the back but powered on okay. I was worried but I thought since it's coming from a computer and electronics reseller, they at least opened it up and looked. No. This machine was clearly sitting in water for an indeterminate amount of time. Various areas of this machine are completely rusted. There appears to be rust on a part of the power supply as well, a wire wrapped part a transistor, maybe? The bottom shell is stained with rust, and the inside part of the bottom shell took three hours of cleaning to get to what you see. I understand the machine was sold as is and it said it would need cleaning, but I'm terrified to even try to turn it on and test it. It looks absolutely dangerous. Look at the bottom shield! There's barely any metal left! The bottom case has been cleaned 4 passes of cleaning solution (I use scrubbing bubbles because a friend of mine that repairs and cleans old electronics swears by it. As long as you rinse the residue off afterwards it's fantastic) and it's still pretty bad. I sent a message to the seller and I will wait to see what he says, but if I had know the level of corrosion on the system I would not have bought it. I don't want to leave the seller bad feedback and if he can assist me with this I won't, but I don't think this machine should have been resold without pictures of the interior. At least he said there was corrosion on it. But there was severe indications of extreme corrosion and rust on the bottom of the case and there is no picture of the bottom of the case. My hope is that it can be salvaged. The piece of material between the bottom shield and the motherboard is toast and there is rust on the motherboard. I will attach some pictures below. If anyone has any suggestions and tips on cleaning everything, I would be very appreciative. Thank you for any information and assistance.

Regards,

Nathan
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Here are some additional pictures for everyone to look at -

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I don't have any pictures of the keyboard, but it looks pretty bad. I knew that going in. I have a key cap remover, so I will carefully remove the keys, clean them and then the plastic cover on the keyboard pcb and it will look much better. I will post pictures of before and after on that for you guys if you are interested.
 
Well, if the damage is primarily limited to the sheet metal shield on the bottom, that's not a stopper. You can go purchase some flashing from the local big box home improvement store and make an approximate replacement with a little work.

What I'd be mostly worried about is water-soaked inductors/transformers and corroded PCB traces (not rust, but can be just as bad). Rust stains can be cured with a solution of oxalic acid (should be available in the paint department--used for cleaning rust stains from wood and concrete).
 
I have been looking over the motherboard carefully. There doesn't appear to be any damaged traces that I can see with the naked eye. I don't have to the tools to check at a microscopic level though.. Aside from some rust on the motherboard, it appears to have survived the water dousing well. I am concerned about the power supply, did you perchance take a look at the picture I took of the part that appears to have rust on it and give me your opinion please?
 
Rust is an issue, wonder if the ebay seller found that machine in a dumpster after it rained. First thing I do locally when snagging somebodies old rig is look at the bottom for rust (happens too often when people store machines on the floor of a leaky basement or storage locker/shed. The RF shield can be replaced easy enough, and small bits of rust on the MB can be removed as other said. You can always find a dead donor machine and swap metal.
 
Hard to say about the PSU. If the thing has been wet for a long time, it's quite possible that the insulation between the windings has degraded. Fortunately, power supplies are generally pretty easy to replace or retrofit.

My standard suggestion is to put a 40W 120V household incandescent in series with the AC input and plug it in. If the system stays dead and the lamp lights to full brilliance, you probably have problems with the PSU (or less likely, the motherboard).

It greatly saves on pyrotechnics, fuses and magic smoke...
 
Well the seller indicated that it was tested to power on. So the power supply does at least spin the fans up. Nothing more than that is known currently.
 
I think it looks worse than it is. Sure, that sheet of metal is toast, but it's not hard to replace as already said. Chuck's suggestion is a really good one, and if it doesn't go pop, you could run it up disconnected from the main board and check the voltages are sane. Anyone got a service manual pdf?

Obviously, replace the usual suspects on the power supply (filter caps).
 
either replace the metal parts altogether, or use electrolysis to remove the rust (no labor required, just a dip). If you need help, pm me. It's not for the squeamish, and unfortunately a lot of fold fall into that category, but you won't kill yourself, trust me, and it's easy.

W/regards to the power supply, well, take it outside w/an extension cord and load the various rails w/suitable loads. Can't say what that would be for sure, but many p/s's will tell you, for instance, the 5vdc rail won't turn on until so many amps are drawn. Something like that. Yes, probably not a good idea to power up the puter if you suspect the p/s is flakey (and it may be flakey down the road, a component that had been damaged by water or whatever could fail at an unexpected time). You should probably think about find a *new*, suitable replacement p/s. Your rig won't be original anymore. But you'll always have the old one to work on one day. Replacement p/s can be had for not too much money (heck you could use a standard pc supply). If you want to go that route, also pm me. And understand this obsession w/everything having to be original is *not* the way things were done back in the day. If a unit was supplied by the oem w/a flaky part, you found a suitable substitute. So just be happy w/your perhaps somewhat jury rigged LOL new appurtenance.

I had a handful of T1Ks that I eventually wound up tossing. They were *not* sitting in a pool of water. The metal Tandy used must have been crap. Sure they were in something less then a dry environment needless to say. No need to automatically suspect nefarious intentions on the part of the seller.
 
@tipc - I cannot say if the intentions of the seller were less than pure or not. I can say that all of the pictures avoided showing any damage or rust except for one picture of the back ports, which were partially obscure. A picture of the bottom would have shown indications of having sat in water for some period of time. It doesn't take long for sheet metal like that to rust when sitting in water, but the plastic is stained to the point that I cannot clean the rust off the bottom outside of the case. I am intrigued about the electrolysis method for removing the rust. I have used white vinegar at a 5% acid solution to clean metal in the past, but I don't think the rust was this bad. It worked great except for the flash rust that is difficult to control. Using a power strip and setting the power supply on an anti static sheet, flipping the power switch results in the fan spinning up. No smoke so far, I left it running for 15 minutes. Granted, I didn't have a load on the PSU, but so far the result on the PSU is promising.

-edit- quick question, is the motherboard in these 1000HX machines a real pcb or is it perfboard type? I ask because I haven't seen this color of motherboard before. And what is the insulation layer between the motherboard and the shield made of? It appears to be some form of paper? Also I haven't done feedback or complained to e-Bay. I have contacted the seller to find out what happened and why if they knew the level of rust that they didn't supply pictures. If I received a machine that was like this, I would not have tried to sell it on. I would have posted it here for someone very determined to clean it and prep it.
 
I'd say that the rusted metal is toast. Even if you manage to remove the rust, it's not going to be smooth--and you'll have lost the nickel anti-corrosion plating at any rate.

As far as the color of the PCB, it's not unusual--that's the way the board starts out--most manufacturers add a layer of colored "resist", but you can get the stuff in clear, red, blue, green, black--just about any color (I've never seen chartreuse, but I wouldn't say that it's never been done).
 
Threatening to leave bad feedback because you got your item 'as is' is bad form in my opinion.

Most of these sellers have no idea what kind of state the internals is in, much less how to open it to check! How is this their fault that you would find corrosion? If I buy something that does not say 'used' or 'new' on the condition, I know I'm taking a risk that it could be a dud. You should know this too.

Obviously you got what you paid for...
 
@mojorific - I haven't threatened to leave bad feedback. I haven't threatened anything. I specifically said I didn't want to leave bad feedback if it can be helped. I wanted to know the history behind the machine and why he didn't include pictures of the bottom of the case, which would given a good impression of the extent of rust inside the machine. The bottom of the plastic case is stained from the rust. I have tried multiple applications of the cleaner I use to clean stains and whatnot, and the rust stains haven't even lightened. I will not name stores or sellers on here because that is bad form, but if I had seen the bottom of the case, I wouldn't have bought the machine. Telling me that I am threatening to leave bad feedback is 'bad form' in my opinion. I was clearly upset, but I never said to the seller that I would leave bad feedback. I said I submitted a message and had questions before I left feedback. Period.

@everyone - I appreciate the suggestions on how to recover the machine to the best of it's ability and I will do what I can to recover the machine. I don't demand discounts on products that I purchase, even if they are in a much more terrible state than listed in the description. I also don't ask for a refund unless the item is destroyed beyond salvage during shipping. If it is even working somewhat, I will do what I can to recover it. Everyone here is under the thought that this machine is completely salvageable and that is what I intend to try. If that means purchasing replacement parts from machines that no longer work, that is what I will do. I will attempt to salvage the shields though and I am hoping that tipc can help me with trying out electrolysis on the rusted metal to eliminate the rust. I don't really have the tools to make my own new shields though. If I did I would just do that and go on my way.
 
If it helps, it was also a practice to make shields from foil-faced cardboard. That may also be an option for you. I don't think that the rusted plate serves much of a purpose other than RF shielding.
 
Chuck(G) said:
If it helps, it was also a practice to make shields from foil-faced cardboard. That may also be an option for you. I don't think that the rusted plate serves much of a purpose other than RF shielding.
Click to expand...

I'm not certain if it is more than RF shielding but the power supply mounts the grounding point for the power supply attaches to the shield and the CGA monitor connector also screws down into the shield. I don't know if that matters or not. I am reading up on the electrolysis instructions to see if I can try that.
 
Easy--a metal bucket, washing soda, water and a battery charger. I use it on old rusty tools myself, but I doubt that you're going to get good results with sheet metal.

Prove me wrong, however.
 
The electrolysis would definitely work looking at the instructions. However it takes some serious time and produces hydrogen which is flammable and I don't have a place I can leave this outside for the several hours it will take treat it. I guess I will go with an acid bath like I have done in the past for light rust and try to treat with a rust spray after neutralizing the acid with baking soda. We'll see if that works in any capacity.
 
If you want to go the chemical route, there's always Naval Jelly - basically phosphoric acid with a few bits of alcohol and phosphate. But it will dissolve the rust.
 
Naval jelly isn't anywhere near as potent as it once was.

On a machinery forum it's been said, granted not by a chemist or anything close, that electrolysis removes the tendency of the metal to rust in the future. It converts all the oxides to something like magnetite. Of course anything can rust up again if it's exposed to an excess of moisture. But supposedly rusted metal is more prone to rusting again. I don't know, don't ask me.

for the rust stains, don't know if clr is compatible w/plastics. There's also just plain gel bleach and 40 volume peroxide. The retrobrite peeps specify leaving their solution on overnight at least. It may take time for the stains to disappear.

Bear in mind that electrolysis doesn't require dipping or a vat. You can soak a cloth in the washing soda solution, lay it against the rusted metal, then lay another piece of metal on top of that, then apply voltage. It works the same. Thing is even a reasonably well stocked scrap pile could easily be missing that ideal piece of scrap that's suitable for the fancy contraption you're concocting. And you really don't want to have to buy metal for this purpose (except maybe rebar). Steel supply houses often sell drops for pennies on the dollar.
 
For rust stains, nothing beats oxalic acid. If you can't find the powder at your local paint store, get a cleaner called "Bar Keeper's Friend" which contains oxalic acid and other cleaning agents. Great stuff.

But I think that you'll never get the sheet metal smooth again--and the nickel plating is gone in any case.
 
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