Corroded Amiga 500 Rev 5 (w/512k ROM upgrade and S-Video out) 

As started Adrian, When I was in my teens (early 2000's), I had an old membrane keyboard from my parents compaq presario 5000t. One day a whole group of keys stopped working. I was able to disassemble the keyboard and using a multimeter I found where the trace had broken apart. (unsure what caused it). Soldering was out of the question on the thin plastic membrane, BUT I used some rear window heater grid paint available from auto parts stores. Comes in a real small bottle with a paintbrush. Painted a few coats over the split and reassembled the keyboard. Worked like a charm.

A lot of the amiga stores sell new membranes as well as a more sturdy replacement. They also sell a rom fix that just plugs into the rom socket for anything above 1.3

Please take your time, Adrian. 2 videos per week is a lot and if you skip one, now and then, noone will be angry. There is no need to ever rush things.

It's nice to see a piece of ITALIAN software running on an American Amiga. :) Logica was an Italian company which produced accessories for the Commodore Amiga line of computers. Amiga had a huge success in Italy back in the day.

I repaired my A500 keyboard with silver contact paint. It's about as expensive as printer ink, but does the job fixing hairline cracks in flatflex stuff if it is under low mechanical stress. So once the membrane is inside the sandwich again, it should be fine. Hint though: let the paint dry, it will not conduct properly when still wet. :) (edit: I still haven't edited the video for that one; it's my oldest "eventually" spare content one but on mine one of the Amiga keys was dead, and you need both for the reset combo)

Adrian needs more iFixit sponsorships, I always enjoy his videos. Greetings to you Adrian from your neighbour to the north in BC.

The only way I know of to fix one of the A500 membrane keyboards is to seperate the layers and clean the contacts with a pencil eraser. It's risky but does work very well in most cases. If you find carbon pads benieth the keys I would use isopropanol and a cue-tip or other cotton swab. For the carbon pad on the key side, just rub it acros some paper until it leaves a good solid skidmark that is the same width as the pad. Note that this trick also works for TV remotes where keys stop working.

Naval Jelly is nothing short of AMAZING! There’s ALWAYS some in my house!

Adrian is at his best when tinkering with an Amiga!!!

To repair Atari membrane keyboards I've used silver conductive paint, for durability I've added a little superglue on top of the silver conductive paint.

Very interesting video glad u managed to get it working well 🙏

Back in the day I used a RGB to Scart connector on my Sony CRT. Looked way better then my 1084s monitor!

Look for broken traces on the keyboard membrane. Use conductive epoxy if you find any.

I have repaired membrane keyboards with a conductive paint, intended for repair of rear window defroster in cars. It works great.

Hi, When you showed use the clean motherboard. It looked like new, good job.

I’ve repaired a few amiga keyboards. Yes there are a few options for membrane replacements. The one I favour is the “hard” membrane replacements, readily available in the UK, sadly I’m not sure of availability in the US. But I’d try fixing first. Having removed the 40million screws (slightly larger screws around the pcb controller to watch for), remove the membrane, place on flat surface and gently wipe with water or if feeling brave some glass cleaner can work well. Sometimes I’ve needed to refurbish the little plunger, some conductive paint can be used (Liquiwire 50mL Electrically conductive paint for PCB & electric circuit repair from Amazon) is what I’ve used with success, dip the plunger into it and let dry. As you say Esc and F1 not working when the rest work usually points to plunger or dirt on membrane. Before going to the bother of getting the conductive paint, try swapping a couple of plungers around. Hope this helps.

After you repair a computer what do you do with it return it to donor or keep it or list it for sell? Really enjoy watching your repair videos on the vintage computers. Takes me back to a earlier time .

Well this video answers a 30 year old mystery of when a computer store I took my Rev5 Amiga 500 could never get it to run a Kickstart 2.0 rom

It shows that it is important to write in a clear way and make sure the information is correctly presented.

Also, the older kickstart roms are a different size. There’s an adapter to allow larger roms.

On the flickering video check the two large caps near the video port. They tend to go bad and can short out. They will also over heat the resistors. I've had that occur on two of my version five boards

wow man. that looks like it was frustrating as shit. props for sticking with it

This was my first computer!! So cool

I really could have done with something like that S-Video adapter back in the day. That combo of the 1702 and the A500 (rev5) was my setup. I used the colour composite out of the A520 modulator. Which was ok but slightly blurrier than I would have liked.

Nice to see we are both members of the 1702 with a front cover club! :)

Nice video as usual - I'm disappointed you didn't use the dremel on those torx screws :)

Great fixes. Another Amiga saved... well, mostly. I bet your Subaru doesn't corner as well as the Lotus Esprit. 😉

We've had rain for most of a week here in Texas, but no basements! The ground is wrong on one way or another for basements, but here it's limestone like a foot or two below the ground.

Cool !! Hello from Brazil !

Naval jelly is basically phosphoric acid and a binder. Bilt Hamber makes the best alternative in Deox-gel. You can make your own using some sort of starch, water, and acid. Phosphoric is particularly nice on steel, because the phosphate it leaves behind is good at holding oil or wax for further protection. Citric acid is common and very mild and benign, leaving clear surfaces. Clean white vinegar is probably the most widespread stuff. Avoid Hydrochloric acid and chlorine like the plague if you care about metals in the room! See also: Parkerizing.

Always good value. Keyboard Membrane Repair, FWVLIW: Just don't, you'll be much happier! ...but if you must, or just don't have an option: (nobody makes replacement membranes for my favourite retro system) 1) Find the schematic and test the leys. This will likely tell you if the issue(s) is/are with: -The connection with the with the computer (I hope you checked that first!) -The controller or it's connections (hopefully the socket or dry solder joints, not the chip itself) -One (or more) of the main row/column traces on the membrane (repairs are easier if any cracks aren't near the keys) -An individual key or local trace(s) 2) Carefully disassemble the keyboard: -Dry clean the key mechanisms and partially reassemble. If you're very lucky it was just guck / grit -Brush down the outsides of the membrane ONLY and give it a gentle flap. Test again, maybe just a bit of grit / guck -Being VERY CAREFUL look for any cracks in the FULL LENGTH of likely tracks by continuity testing and then magnification to find the exact spot(s) -No clue? AMAZINGLY CAREFULLY push a FLATTENED cotton bud tip between the membranes where the key presses and GENTLY rub both sides (It may be the pads have a bit of build-up that is preventing conduction, hopefully you shifted it without scrubbing off the usually very delicate film) -If you found a cracked trace you can effect a repair with a product like Wire Glue, Silver contact paint, or similar... a) It's amazingly important NOT to daub it on - claggy lumps ruin membranes. Whisker-thin dab, dry, test, more if necessary... b) If the crack(s) is anywhere near a key actuation spot you are almost certainly NOT going to effect a successful repair, but try if you must. Second last resort: If it really looks like all the traces are good, it's just that the pads under the key(s) are worn out you may get away with the old drawing on the pads with a soft led pencil trick, taking care NOT to distort or scratch the plastic. If this works at all it probably won't last long. Alternately a very VERY thin layer of Wire Glue or similar might help. You can even try applying a small circle of gold leaf!!! (expensive, horribly fiddly) Last (first?) resort: You could design your own replacement keyboard PCB to interface with the old logic. Not as hard as you might think - there are online resources to help. Two options: a) A PCB with SMT tact-switches or dome switches to go where to old membrane lived. If there's room, great. If not you may need to sand a little off the bottoms of the old key plungers - this will leave you with a seemingly authentic keyboard that's more reliable and a better action. Best to order a PCB thinner than the standard 1.6mm if you can, some manufacturers will even do flexible ones but they are horribly expensive and they aren't necessary. An awesome mod for the old rubber-key ZX Spectrum, but it works for many mechanical keyboards too. The old membrane will serve as a template for your layout. b) A complete new mechanism using modern mechanical switches - more fashionable and possibly more robust and future-proof. But modding old keycaps to fit new switches is a bugger, as is finding new keycaps that look the part. Then there's the whole "Am I going to have to design / program my own controller too?" I hope that helps someone.

When the screen hits your cam, like a big swirly spam, that's a moiré

Hello from Portland! I am currently working on my 500 rev 5. Hunting down a 1Meg Agnes and seemed to have lost the screws for the keyboard (replaced the membrane a couple of years ago) and the case.

One thing I am going to miss about living in Portland is the rain.

You had some bad luck with that revision 5 A500, A500 normally in good condition, except for Rev 8's, nice job!

Thank you Adrian! I just got request to fix A500. So that might be helpful.

If I remember correctly those mitsumi keyboard membranes are actually single layer and there are rubber plungers which make a connection between 2 pads to register the keypress (in the same way as the c64 keyboard works). I'd be tempted to take the keyboard apart and check that the issue isn't simply that the rubber contacts on the bottom of the plungers are dirty for those two keys and hence are not making a good connection or that there isn't just a bit of fluff in there thats preventing those keys from making a good connection.

Rainy December?? We are in February!!

Don't need those two keys for Lemmings so... win win!

Great video Adrian! Have you ever used that CLR Calcium, Lime, & Rust Remover stuff to clean contacts on any vintage computer?

I owned a C64, but never got an A500 as a teen. Still hoping for an A500 Maxi sometime. A MEGA65 would also be great, but the price is too high for me.

I usually just disassemble the keyboard and clean the plungers and the membrane with windex. Quite simple to do and most often solve any keyboard issues.

I like the hard membrane replacementa

Hi Adrian. There's something in the UK called JENOLITE Rust Remover Thick Liquid. Not used it myself, but it looks pretty similar to Naval Jelly.

If the keyboard is anything like most keyboards with a membrane sensing mechanism, you should be able to separate the layers of the membrane and clean up whatever gunk is on there and use a conductive silver pen to redraw the traces. That's what those pens are actually designed for! Also useful for membrane flex connections that use that same silver trace material that can wear off. Make sure it's using paint and you let it harden completely. A rather easy fix honestly.

The membranes on the A600 and A1200 usually fail because of the wear and tear on the flat flex from moving, unplugging and reconnecting the keyboard to the motherboard. Since the A500 keyboard membrane is usually left attached to the integrated controller board it is more robust. A500 keyboards tend to be older than A600 or A1200 ones and the individual switches are a more likely point of failure through loss of conductivity. Repair should be possible with cleaning/conductive paint or replacing the key plunger with a spare from a broken keyboard.

Notification Squad! :D

I had the same VIP video adapter and I too saw the interference when accessing the floppy drive, although to a lesser degree.

4:45 "Inside the computer's a bit of a musty odor so, this thing was obviously stored...outside..." LOL!

Navy Jelly I was thinking belly button jelly LOL!

I remember having a Workbench 1.2 Amiga 500 as a kid. It was also weird in that it could handle 1.44mb HD Floppy disks, I'm pretty certain they were only supposed to be able to handle DD disks. I do miss that quirky machine!

What you call "Workbench" in the beginning is actually called "Kickstart" :-)

Adrian I can't remember if that model has the audio output reversed caps on the motherboard that need to be changed I think it was all the 500 models.

The day was going straight into the toilet... but now, this video marks the day's turnaround! Heh

I used silver conductive paint too on my rev5 keyboard years ago to repair some traces. I remember detecting them by looking to the membrane in front of a lamp, then you see clearly the gaps on some traces. I have tried a chinese copper conductive pen but didn't work for me, only my old silver paint did the job.

Naval jelly is phosphoric acid with a gelling agent.

New membranes are available but not for the one which uses 2 ribbon cables AFAIK. You can even get a 'pcb' type membrane instead of the original type. It's well worth changing the two larger capacitors near near the power input jack, they're notorious for failing and causing issues when accessing disks.

I cry for the Amiga

A non-working key can be either a result of a faulty membraine (one path rotten - can be fixed with a conductive paint) but it also may be due to oxidation of a plunger - you won't know it untill you disassemble it.

I'm guessing it was stored vertically with the left side down, so any/all water(?) corroded that connector and plating parts. Possibly also the ESC and F1 key issues?

Re: Keyboard. With the Mitsumi keyboards it's often not the membrane that's the problem. Instead it's the carbon impregnated rubber on the bottom of the stems. This will often oxidise and become non-conductive if left in a damp environment. You can buy carbon paint, often sold for garage door remote button and remote control button fixing to get them working again.

For what it’s worth the lid of the ifixit case is good for holding screws

If you're using the Diag rom, why was there no null modem hooked up to capture the output?

a total stranger to cellars I would like to learn more about the sump pump. Is it catastrophic if it fails while raining for days. And havent seen rain for ages so would like to see that too

25:01 "You know what, this has got to be because this thing is running NTSC and I think it's designed for PAL" Hmm, that explains why it says "NTSC Will Fail" directly above it.

About audio, only from A1200/600 you have mono sum on the RCA. Original models 1000-500-2000 are stereo only

I'm sure I heard you wrong, but it sounded like you said the Amiga 500's video output was monochrome? I seem to remember full color graphics when I had mine plugged into the monitor.

I had a Rev5 Amiga, and when I replaced the Kickstart ROM with 1.3 It did not require any bodgewire for my system. The only issue it seemed to have was a serious problem with my 3rd party bootstrap ROM for my 20MB HDD, it would hang for up to a minute on a gray screen before booting from the HD. I ended up just booting Workbench from floppy and using the HD as storage until I sold the whole thing to help finance my first PC in 1992.

I had an Amiga 500 a couple of years ago where some important key was not working and it had a plunger type thing that I moved over from a less important key. I don't know what type of keyboard that was, cleaning didn't help with those plungers.

I wonder if you should keep one of your low cost oscilloscopes connected to a video cable, for better "sign of life" testing than various video digitizers.

If the membrane is dirty just split it apart at the F1 and Esc keys and clean the contacts with a pencil eraser first. If that doesn't work try a tiny bit of the carbon conductive paint. I actually used aquadag paint myself, I didn't want to spend the money for the membrane paint.

Adrian, how did you boot from the external gotek drive?

I have seen some people having minor success using a conductive ink pen to repair connections on those type of membranes used in the keyboard, can't guarantee anything but it could be worth a shot.

Which video output was monochrome? I remember hooking my A500 up to a 1084 with full color (the 23 pin connector?).

When did you get the I Fix It screwdriver kit?

if it's a membrane of rubber domes... then I've done similar, since many game controllers and remotes use similar tech. Typically, the membrane has a graphite patch in the center, which shorts across two exposed copper contacts when the key is depressed. Just like many game controllers. If the membrane itself is intact, but the contact pad is bad, it's just a matter of affixing a suitably conductive substance to the contact patch. I've done it only on NES controllers, calculators, and a TV remote -- short term, graphite worked, but needed redoing. Aluminum foil did not work - -the oxide layer isn't great. Copper detailing foil did work. (Scaring me to think that was 30 years ago.)

24:00 does it have a setup Mode where you can force it into ntsc?

Naval Jelly will attack paint and galvanized metal...so use with care. I've used it a lot for car stuff.

Is there a Control+key combo you can use as a temporary substitute for the Escape key, like Control+[ on early IBM and Apple machines?

You could try some method of cold soldering, aka condutcive glue, to fix membrane if trace went bad, but it could be just dirty. Only way to find out is disassemble it and take good look, im affraid.

It's important to remember that S-Video is *not* the same as the Y/C input on the monitor you're using. It operates at a lower voltage on the chroma pin. To bring it up to standard for your 1702/1084 you'd need a small amplifier on the chroma circuit.

I've tried using all sorts of paint on conductive stuff to fix worn out or broken tracks, but I have never had it work and just given up.

There are membranes available. I still have one laying around.

There exist a silver, that can be used on these membranes, to recreate the circuits on these membranes. So the contact will be as new.

Having a double size ROM with the largest address pin floating isn't much of a problem if you just write the ROM binary in there twice so that both halves of the memory have the same content.

Because you had Kickstart 1.2 it would had been interesting to see the label underneath. Most likely a 1987 model. I bought mine 1988 and am pretty sure had Kickstart 1.3 right away. For Test Drive. Yeah, HP of Porsche, Ferrari and others are ridiculous today. But prices too. Don't think you get a new 911 for 50K these days. Also the game was made in Vancouver! Yay Canada! I think I had it back in the day, but never noticed it was made in British Columbia.

So there was orange juice spilled on the ESC/F1 region and ran all the way down the CPU connector to the green and rusted screws🧐

Adrian if i was you i would make an adaptor for the eeprom from a chip socket with the modification on the socket so as not to mess up the diag rom

Any time Adrian is about to put something in a socket that's suspect, I always say "DEOXIT THAT SOCKET!" and pray he says the words. They're the magic words, if you don't say it, the computer never works guaranteed.

I am a bit confused.... In have always believed that the A500 had an RGB port built in and connected directly to a 1084 monitor, with color. My wife had both when we met and we played tons of great games on it. But it sounded like Adrian said that the A500 was monochrome without the adapter that he was using here. Edit: yes. He said that both the 500 and 2000 only had monochrome as native output. But I feel pretty sure that this is not true. Anybiy else able to confirm?

Does this model have ray tracing?

I once fixed such a keyboard with some kind of silver paint. No idea what it's called. It's been a few years...

Of course you drive a Forester and live in Portland what else could it be. Just remember the cool kids drive vintage Elements.

It's only one of the audio outputs that gives a combined signal. (I think it's the left channel.)

Yeah the rains are getting more and more intense. Here in NC we've started having more thunderstorms in the winter which is weird. IIRC we've always had them but not as frequently or as heavy.

to fix the keyboard problem, you have to disassemble it and use silver contact paint and repaint the traces.

Fun fact the mono composite is generated by video hybrid circuit

If I remember correctly the 1.2 Rom is what the 500 was first released with.My 500 came with the 1.3 Rom no wire was needed.

LOL, the Lotus weighs about 1,300 pounds less than (65% of) your Subaru Forester XT. Colin Chapman (founder of Lotus) philosophy: "Adding power makes you faster on the straights. Subtracting weight makes you faster everywhere." Just sayin'. ;-)

Naval jelly is phosphoric acid.