Good Samaritan Rule?

If this is aimed at me, and I think it most certainly, is, then you might say so... There's something that I find offensive too. And that is being flamed for offering what I consider to be correct advice. Please remember that I give my time, knowledge, and experience freely. If people here don't want such advice, then tell me and I will leave. I've thought about leaving several times due to being flamed for things like this. And I can assure you that _I_ will not be the loser.... Oh, for %deity's sake. Nobody is going to sue anybody, surely. OK, let me make a few points. You started by asking for methods for undoing stuck screws. I provided a number of such methods that have worked for me in the past (note : I have never needed to use a hammer or similar tool to dismantle _any_ part of a classic computer, but I digress). I also suggested that there might be an alternative method to do what you wanted to do (namely to remove the parts from the monitor chassis). I have learnt many times over that if somebody is asking how to do something, it's best to find out what the _real_ problem is as there may be an alternative solution that's easier, better, or whatever. I know some people don't like being told they're going about it the wrong way, but.... Also, you now say that the 2 monitor chassis assemblies have the same part number. In this case, I think it's safe to assume they _are_ compatible (in fact they might well be identical). So the height problem is certainly not an incompatability. It's most likely a fault. In the circumstances, the first thing to try when the height is too low is, most liklely, a tweak of the height control. To be honest, I'd probably have tried that too (knowing that a height controller, as opposed, say, to a disk controller PLL adjustment, is easy to set correctly). But when you find that you can't get enough height out of the monitor that way, then the next thing to do is not to look for more adjustments, but to look for the fault. The fact that the height control was sealed with silicone rubber should have indicated that most likely this is not a common field adjustment. In other words you should be able to drop any monitor chassis in place of any other without having to adjust things -- they would have come correctly set up from the factory. In which case the lack of height would suggest a component fault. Now, as to what I would have done differently, had it been my machine.... My first thought would have been to swap the CRT only. Not the entire monitor. For at least 2 reasons it's a good idea to replace as small a part as possible. Those 2 reasons are : 1) Historical accuracy -- keep as much of the machine original as possible. There may have been changes in design that happened during the production life of the machine (I know plenty of examples where this did happen). You don't want to confuse people by having the 'wrong' parts fitted. 2) Lack of incompatibilites. Often seemingly identical subassemblies can have subtle differences. I've been caught with this too often. I prefer to keep with parts that I _know_ have once worked together and therefore can be made to work together again. My second thought would be to look for faults when tweaking an adjustment doesn't have the desired effect. IMHO classic computers are repaired by very different procedures now to how they were repaired when in current production. For one thing, there's no source now of known-good FRUs for most classic computers. Even New-In-Box parts can have failed in storage. Therefore, it's necessary to do a lot more tests and a lot less module-swapping. But since this is a hobby for most of us, we don't count the time we spend looking for the fault. The time doesn't matter, the cost of parts might. It's cheaper to replace a small component rather than an FRU, too. For this reason I often ignore much of what is printed in the official service manual for a classic computer. I will make use of the 'reference data' -- the schematics, pinouts, voltage charts, waveforms, source listings and so on. But I almost always ignore the fault-finding charts. I work from the schematics, making measurements, checking waveforms, and figuring out what is really going on. There is an attidude here that I find hard to accept. I have no problem with the fact that you are probably relatively inexperienced in fixing monitors (or analogue stuff, or...). Everybody has to start out somewhere. I can remember making a lot of mistakes when I was starting out. The thing is, I was prepared to learn from my mistakes, from my problems, and so on. I don't consider that learning should stop just when you leave school (or university, or...). I want to stop learning the day that I die, and not before. There are many things (related to computers, electronics, engineering) I don't know. And many things I've learnt due to working with classic computers. My attidude if I come up against something that I don't know (like 'How does the vertical deflection system of a monitor work', or 'How do I write a device driver') is to go away and learn about it. Read books, experiment, ask questions, etc. And then I have got a solution if I ever come against the same problem in the future. Repairing and using classic computers is a hobby for most of us here. A hobby is something we do because we want to do it, it's fun. This doesn't mean that everything I do related to classic computers has to be enjoyable. But equally, if I found that everything was unenjoyable then I'd find some other hobby. But I consider learning to be an integral part of this hobby. OK, so you have a monitor that's not working right, how do you learn about it? Well, I am going to assume that the manufacturer never provided a schematic or component level repair manual. But a mono monitor is like the last few stages of a monochrome TV. So we look at books on repairing TVs. (There's a good reason why I have 30 years of tha annual 'Radio and Television Servicing' books on the shelf). We look at circuit diagrams for TVs. We look at the monitor and try to identify the main components -- at least the ICs. If the numbers are unreadable, then we trace enough pins to make a sensible guess as to what the chip must be (this is something that, I will admit, comes with expeirence). We try to find circuits in TV repair books that use similar components. And then try to match up the other parts -- the resistors and capacitors round the chip. Most likely they'll not tbe the same value, but the arrangement -- the circuit topology -- is often very similar. There are only so many ways you can use a particular chip. For example I had a problem with a Hitachi colour monitor on my DEC Rainbow. It was badged DEC VR241, but it was certainly a Hitachi chassis. The vertical output stage was part of a ceramic hybrid module. A look at some early 1980s Hitachi TV schematics producted one using a hybrid with almost identical circuitry from what I could deduce about the one in my monitor. Needless to say that schematic was a great help. If 'ME' = Mechanical Engineer, then I am even more suprised by the use of a hammer. I've never used a hammer for any mechanical engineering that I can remember. I'm not an engineer at all. I am also not a 'doctor' in this sense. You don't need an electronics lab. FWIW, the tools I most often need to fix computers (including test gear) will all fit into one normal-sized 'holdall' bag. In fact I take them along to HP calculator club meetings. [That, BTW, is more than can be said for my 'mechanical' toolkit which is most definitely not portable] But, more important that tools or test equipment, IMHO, is the ability to think about what you are doing and to stop and think if there's a better way to do it. Nobody is going to flame you for making a mistake. I've debugged several computers to component level using nothing more than an analogue VOM (multimeter) and a bit of experience. Test equipment is not a magic box that will find the faults for you. I keep on about experience. Yes, some of us have been working on such machines for rather a long time. And _all_ of us (if we are honest) will admit to making mistakes. Sometimes very silly mistakes. But experience comes from mistakes, provided you are prepared to realise that you have made a mistake and what uyou did wrong. No, please carry on. The only way to learn is by doing things. And keep on asking questions -- that's another good way to learn. But bear in mind that if you ask for advice it may not be what you want to hear. It may help you in the end, though -tony