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rebeltaz
February 11th, 2009, 06:40 PM
I now have six freaking c64s with the same problem! I don't understand how this computer ever made it if it is this sensitive.

I was using one that was working fine. No problems at all. I turned it off - computer first, then disk drive and then monitor - unplugged everything and set it all aside. I hooked it back up to day - in the reverse order - and the freaking thing is dead. Blank black screen with the disk drive light held on.

I have one last 64 working and I am scared to even look at it, much less hook it up!

And before any one asks... it wasn't the power supply! Voltages are still normal, so this can't be construed as a failure of the circuit I built.:rolleyes:

Is this really this common of a problem that I am unlucky enough to come across six out of seven that either don't work at all or fail within a few hours of use?

Druid6900
February 11th, 2009, 06:59 PM
Several of the ports on the C-64 are directly connected to static sensitive chips.

Brush your fingers over those ports (I think the joystick ports are famous for it) and, POOF, Fried CMOS chip

Trixter
February 11th, 2009, 08:32 PM
There is an old C64 demoscene demo that tells you to rub a wet finger over the joystick port to continue (seriously) :-)

NeXT
February 11th, 2009, 09:01 PM
I'm assuming you are not wearing just socks and walking on 1" shag carpet, correct?

rebeltaz
February 11th, 2009, 09:11 PM
I'm assuming you are not wearing just socks and walking on 1" shag carpet, correct?

:rofl:

No... No... I always work on these things buck naked to keep down the static!

Unknown_K
February 11th, 2009, 09:37 PM
I blew up my original C64 back in the day by having one hand on the keyboard while touching the TV screen with a finger from the other hand (blew the RAM).

vwestlife
February 11th, 2009, 10:10 PM
At my old job we had PalmPilot serial-port docking stations that were repeatedly frying the serial ports on Dells. Dell didn't include the appropriate static protection on their motherboards and it was a common problem, but Dell claimed it was Palm's fault for making a static-prone product and Palm ended up getting sued over it. Touching the pins on the docking station with your finger was the instant touch of death.

Anyway, as for the C64s... check the power supply voltages under load, not just while idle. A faulty power supply may have voltages that dip too low when you turn the computer on. Also I believe the C64 has a fuse on its motherboard; I know my C16 does. The PS might also be spiking too high and blowing the fuse (or other components, unfortunately).

tezza
February 11th, 2009, 10:16 PM
Several of the ports on the C-64 are directly connected to static sensitive chips.

Brush your fingers over those ports (I think the joystick ports are famous for it) and, POOF, Fried CMOS chip

I'm not sure if this is the problem in this case, but I have to admit having naked (chip-blowing!) joystick ports so close to the power switch is a major design flaw with the C64. I blew one of mine up by brushing the pins with a finger while turning it on.

Tez

vwestlife
February 11th, 2009, 10:27 PM
I'm not sure if this is the problem in this case, but I have to admit having naked (chip-blowing!) joystick ports so close to the power switch is a major design flaw with the C64. I blew one of mine up by brushing the pins with a finger while turning it on.
Hmm... maybe that's why the Amiga 500 moved the power switch onto the "brick on a leash" power supply itself, and off of the computer entirely... avoid the problem, rather than fixing it?

Merlin
February 12th, 2009, 12:01 AM
Try opening the case and re-seating the socketed chips, they can suffer from 'creep' and work loose. I had one that just gave a black screen until I re-seated the chips securely.

patscc
February 12th, 2009, 05:19 AM
The CIA (6526) is notorious for shorting out.
I was wondering, the power brick isn't grounded, is it ? I wonder if it would help to ensure the computer has a ground connection ?

Haven't seen it posted yet so I will:
http://personalpages.tds.net/~rcarlsen/cbm/c64cdiag.txt
patscc

Vint
February 12th, 2009, 07:17 AM
. . . Blank black screen with the disk drive light held on. . . . I have one last 64 working and I am scared to even look at it, much less hook it up! . . . Is this really this common of a problem that I am unlucky enough to come across six out of seven that either don't work at all or fail within a few hours of use?

As others have stated, static electricity is bad news on chips but let me relate my experience just for 'comparisons'. I used a C64 for 10 years - had the case open many a time, making mods and whatnot. (I also had shag carpet and a dry house all winter.) Other than the usual cautions of touching something metal before sticking your fingers in the box, I never had any 'shorting' problems with any of my Commodores in all those years. So, I wouldn't rule 'in' or rule 'out' static - but I wouldn't be too hasty about giving over to zapped chips due to static right away either.
Try Merlin's, and vwestlife's suggestions, before throwing in the towel.

carlsson
February 12th, 2009, 08:12 AM
Out of curiosity: have you had all six C64s connected to the same floppy drive? Perhaps it has some fault that makes it send high voltages through the IEC cable, effectively frying the 6526 CIA chips one at a time. How about this happens when you power off the drive?

cybertron
February 12th, 2009, 03:18 PM
Does the disk drive have a separate mains lead? Maybe there is a problem with the common ground or earth connections on one of the devices causing stray voltage to zap things.

rebeltaz
February 12th, 2009, 07:44 PM
In answer to the questions about the disk drives, some of these computers were never even hooked up to a drive, and I've used three different drives - so I don't think that's it.

I reseated the chips in the last one I was using, and it didn't do any good. I resoldered a few cold solder connections I found, but that still did no good. Then all of a sudden, for some strange reason, the dang thing started working again! Beats the heck out of me!

vint --> I'll be honest, in twenty years working on electronics and computers, I have NEVER had static damage a chip. I remember one time, a friend of mine was handing me a RAM stick. When I went to reach for it, I swear, no lie, a two inch spark jumped from my finger to the module. I just knew it was fried, but it was the only one I had at the time, so I figured I might as well try it. That RAM module outlasted the computer!

carlsson
February 12th, 2009, 10:22 PM
Perhaps the computer power supply is failing still, and despite your protective circuit you don't observe it.

cybertron
February 13th, 2009, 10:30 AM
In answer to the questions about the disk drives, some of these computers were never even hooked up to a drive, and I've used three different drives - so I don't think that's it.

I reseated the chips in the last one I was using, and it didn't do any good. I resoldered a few cold solder connections I found, but that still did no good. Then all of a sudden, for some strange reason, the dang thing started working again! Beats the heck out of me!

vint --> I'll be honest, in twenty years working on electronics and computers, I have NEVER had static damage a chip. I remember one time, a friend of mine was handing me a RAM stick. When I went to reach for it, I swear, no lie, a two inch spark jumped from my finger to the module. I just knew it was fried, but it was the only one I had at the time, so I figured I might as well try it. That RAM module outlasted the computer!

I've found that generally, the old dual in line pin through chips are very robust as far as static is concerned. I have found that the more modern surface mount devices can be zapped. I managed to zap a Power PC processor module in a machine I was working on and it drew 15 amps afterwards, frying the regulator circuits on the daughter board.:p

rebeltaz
February 13th, 2009, 06:00 PM
Perhaps the computer power supply is failing still, and despite your protective circuit you don't observe it.


I guess anything is possible....For the time being, I am enjoying the one system I have running. I downloaded a lot of images from the net that I transferred to disks and I found a whole stash of disks I didn't even know I had!

Thanks...

rebeltaz
February 15th, 2009, 10:28 PM
Well, I'm a little happier now... out of the five not working I was able to repair two of the them tonight and verified that most of the chips on a third are working. Someone had put U3 (Basic ROM) and U4 (Kernal ROM) in backwards and I had to replace U31 (a 7701) on one of them, and on the other one I had to replace a 5 volt regulator (VR2) and U19 (the VIC II). On the third, the only chip I found bad was U17 (the PLA).

What I did was after getting the first one working, I swapped each chip from the third computer to the working computer one at a time. If the computer still worked, I assume that that chip was good. After swapping every socketed chip and only finding the PLA bad, I unsoldered U7 (the 6510) and U8 (the service manual calls it a 7406, but the chip was stamped 7707) and tested those as well, soldering in sockets before replacing them. The only other chips that are supposed to cause a blank screen are the RAM ICs U9-U12 and U21-U24. None of them are running any where near hot, so I assume none of them are shorted.

That is a lot of unsoldering to be done on a double sided board. I seem to recall seeing something about testing RAM chips by piggybacking known good chips on top of the suspect chips, but I can't find it now. Can someone tell me more about how to do this, if it can in fact be done this way?

I want to thank every one for all of your help and advice...

channelmaniac
February 16th, 2009, 05:43 AM
Sweet!

It feels great to be able to bring an old system back to life. :D

RAM chips can be piggybacked but I haven't had a lot of luck in doing that to the C64.

If you have a logic probe it'll help you "look" at the signals on the chips and can help you determine which RAMs are bad based on those signals.

It can also help you find bad mulitplexers as well. (The address lines are multiplexed on the DRAM ICs - That's how you can get 16 address lines on a 16 pin chip.)

Also, Commodore used several 74xx logic chips they made themselves. They were stamped with their own part numbers.

65245 = 74LS245
7707 = 7406
7708 = 74LS257
7709 = 74LS258
7711 = 74LS139
7712/8712 = 74LS08

They also had a 7714 which I haven't figured out a cross for yet.

Raymond

rebeltaz
February 16th, 2009, 08:46 AM
Sweet!

It feels great to be able to bring an old system back to life. :D

RAM chips can be piggybacked but I haven't had a lot of luck in doing that to the C64.

If you have a logic probe it'll help you "look" at the signals on the chips and can help you determine which RAMs are bad based on those signals.

It can also help you find bad mulitplexers as well. (The address lines are multiplexed on the DRAM ICs - That's how you can get 16 address lines on a 16 pin chip.)

Also, Commodore used several 74xx logic chips they made themselves. They were stamped with their own part numbers.

65245 = 74LS245
7707 = 7406
7708 = 74LS257
7709 = 74LS258
7711 = 74LS139
7712/8712 = 74LS08

They also had a 7714 which I haven't figured out a cross for yet.

Raymond

I'm not ashamed to say that I was grinning from ear to ear after repairing those systems - kinda like this: :-D

I do have a logic probe or three :rolleyes: but I would have no idea what I was looking at. The last time I used a logic probe was probably 20 years ago and that was on circuits that I had built, so I knew what to look for and where....


edit
Actually, I was just reading through the service manual and I may be able to figure this out after all. And I found a SAMS Troubleshooting and Repair Guide that should help.

vwestlife
February 16th, 2009, 08:50 AM
It's rather nice that the programmer's manual for the C64 includes full schematics. This should help you a lot if you have it. It should also be available somewhere online if you don't. I know there's one web site which has nice large PDF scans of the SX-64 schematics.

carlsson
February 16th, 2009, 09:22 AM
Most Commodore schematics can be found here:
http://zimmers.net/anonftp/pub/cbm/schematics/index.html

Some documents may be repeated here:
http://www.commodore.ca/manuals/default.htm

rebeltaz
February 16th, 2009, 10:36 PM
Yeah, I've got the Service Manual and like I said, I found the Troubleshooting and Repair Manual. Both were indispensable in repairing these things.

tezza
February 17th, 2009, 12:50 AM
Good one. As others have said, it's very satisfying bringing a system back from the dead.

Tez

Druid6900
February 17th, 2009, 09:46 AM
That is a lot of unsoldering to be done on a double sided board. I seem to recall seeing something about testing RAM chips by piggybacking known good chips on top of the suspect chips, but I can't find it now. Can someone tell me more about how to do this, if it can in fact be done this way?



This is what I wrote about it and it seems to work as well on a 64 as anything else.


Shorted RAM chips, especially 16K ones will be HOT, hot enough to burn the chip info into your fingertip in less than a second.

On a chip with an open circuit, in most cases, piggy-packing will complete the circuit through the known good chip.

If you have MORE than one open chip (and I have seen it happen), you will probably notice a change in the "garbage" on the screen. You should leave a chip piggy-backed on that chip and use another to continue.

Ideally, if you have enough chips, each one should have a chip PB'd on it and, if the garbage clears up, remove one at a time until you get garbage, then replace it and continue, the chips that are still PB'd at the end is/are the bad one(s).

It doesn't work 100% of the time, but, damn close.

If having a PB'd chip on all the RAMs doesn't clear up the garbage, you should be looking somewhere else.

rebeltaz
February 17th, 2009, 07:49 PM
This is what I wrote about it and it seems to work as well on a 64 as anything else.

Hmm... that mentions garbage on the screen. I was under the impression (from the service manual) that a faulty RAM chip could cause a blank black screen. Would that require that one or more of the RAM chips be shorted instead of open? If so, then that probably isn't my problem, since none of the chips are running warm, much less hot.


Sweet!
It feels great to be able to bring an old system back to life. :D
Raymond

Good one. As others have said, it's very satisfying bringing a system back from the dead.
Tez

Very satisfying indeed! And I'm on a roll... In addition to the C64s, I also resurrected a ColecoVision with cold solder joints and an Atari 5200 with a defective flip-flop this weekend. I guess I better work on the TRS-80 while I'm on a roll before this streak ends!

Druid6900
February 17th, 2009, 07:59 PM
Hmm... that mentions garbage on the screen. I was under the impression (from the service manual) that a faulty RAM chip could cause a blank black screen. Would that require that one or more of the RAM chips be shorted instead of open? If so, then that probably isn't my problem, since none of the chips are running warm, much less hot.

A defective RAM chip can cause, oh, about a dozen different problems, depending where in the memory map the defect resides.

Believe me, if a RAM is shorted, the finger test would let you know PDQ. If the RAM IS the problem, it has to be an open.

As a long time electronics repair tech, I can almost guarantee that any problem you have is NOT in the trouble shooting guide.

rebeltaz
February 17th, 2009, 10:31 PM
As a long time electronics repair tech, I can almost guarantee that any problem you have is NOT in the trouble shooting guide.

Amen to that...

Terry Yager
February 17th, 2009, 10:52 PM
Even if the problem is covered in the service manual, the repair procedure will read "Replace the MainBoard"...with detailed diagrams and instructions how to remove the two screws holding it in!

--T

chuckcmagee
February 18th, 2009, 12:28 AM
For the shorted ram test, I am thinking "Best to lick finger first?" Likely, I still remember my 2nd degree burn from "testing" a cyrix doubler chip I had installed 90 degress from where it belonged. Nice lymph bubble on my finger.

tezza
February 18th, 2009, 12:41 AM
Even if the problem is covered in the service manual, the repair procedure will read "Replace the MainBoard"...with detailed diagrams and instructions how to remove the two screws holding it in!

--T

LOL! Aint that the truth! Especially IBM manuals.

Tez

Terry Yager
February 18th, 2009, 01:27 AM
LOL! Aint that the truth! Especially IBM manuals.

Tez

I just realized I'm thinking of old-skool manuals. Modern ones are dumbed down for today's techies. They simply read, "Jack up the computer and drive a new one in under it."

--T

Unknown_K
February 18th, 2009, 08:35 AM
For the shorted ram test, I am thinking "Best to lick finger first?" Likely, I still remember my 2nd degree burn from "testing" a cyrix doubler chip I had installed 90 degress from where it belonged. Nice lymph bubble on my finger.

I still remember the AMD 486/80 I installed 90 degrees off in the socket (hey it fit), melted the chip into the socket.

Unknown_K
February 18th, 2009, 08:37 AM
I just realized I'm thinking of old-skool manuals. Modern ones are dumbed down for today's techies. They simply read, "Jack up the computer and drive a new one in under it."

--T


Old school manuals were written by english majors in ENGLISH, todays manuals are written by Indians who are too dumb to make the cut at IBM Bangalore headquarters so they write manuals in Engrish to pass the time.

frozenfire75i
February 18th, 2009, 08:52 AM
Yes thats ture IBM manuals are bad that way when thay tell you replace it, but you gotta stop and think IBM worte those with the mind frame that replacment parts were everywere and that was the case back then, and when the next model of the comptuer came out you were expected to throw out the old one and start again.

There's not a part of the manul that's labeled "20 plus years later do this" :-D



LOL! Aint that the truth! Especially IBM manuals.

Tez

vwestlife
February 18th, 2009, 03:50 PM
Yes thats ture IBM manuals are bad that way when thay tell you replace it, but you gotta stop and think IBM worte those with the mind frame that replacment parts were everywere and that was the case back then, and when the next model of the comptuer came out you were expected to throw out the old one and start again.
And don't forget that it is standard operating procedure for service technicians to not diagnose individual components on circuit boards. It is more cost effective and time effective for the service tech to just replace the entire board rather than try to trace the fault any further than socketed components. And eventually the manufacturing process improved enough that the only socketed chips left were the RAM and CPU. Anything beyond that means "Replace system board" is the official bottom line.

Druid6900
February 18th, 2009, 07:08 PM
LOL! Aint that the truth! Especially IBM manuals.

Tez

Read a Mac service manual some day. It won't take long.

Druid6900
February 18th, 2009, 07:22 PM
And don't forget that it is standard operating procedure for service technicians to not diagnose individual components on circuit boards. It is more cost effective and time effective for the service tech to just replace the entire board rather than try to trace the fault any further than socketed components. And eventually the manufacturing process improved enough that the only socketed chips left were the RAM and CPU. Anything beyond that means "Replace system board" is the official bottom line.

When I ran a Radio Shack Computer Repair Depot, we worked at component level for two basic reasons; we trained to REPAIR things, not replace them and, the price to the owner was much lower even with the board exchange program which got you a new Model I logic board for $220.00 plus labour. Not good for some poor kid that saved every penny to buy himself a computer.

The only time we replaced boards was for customers that had on-site service contract to get them up and going. Then the board was brought back, repaired, tested and put back in inventory. I'd be damned if I was going to send something back to head office to let someone else repair it.

Now-a-days, I doubt that, except that one end is hot, most "technicians" (read: board swapping chimps) know which end of a soldering iron to grab.

I'll still replace LSI surface mount chips when the need arises and even tackle unsoldering pinned chip on a six-layer board. It's how I was trained to fix electronics.

rebeltaz
February 18th, 2009, 09:35 PM
I don't get to work with very many service manuals on TVs anymore, but I just got a new laptop and I swear to you the QuickStart manual that came with it did not have a single word on it! All it has were four pictures. The first one depicted putting the battery in, the second one showed opening the lid, the third showed plugging the charger into the laptop and the last one was of a finger pressing the power button. I'm just curious - When did we all go back to hieroglyphics?

And as for component level repair, I agree with Druid - I have customers call all the time who have already called the other two repairs shops in the county (did I mention consumer electronic repair is a dying business?) and the techs there told them that you could no longer get replacement parts for their particular televisions. Of course, the repair parts that are 'unavailable' are complete boards. Needless to say, I have had numerous satsified customers when I was able to repair their units despite the fact that 'parts were no longer available.' It seems like todays so-called technicians either only know how or only want to replace entire PCBs rather than take the time to troubleshoot the board down to the component level.

chuckcmagee
February 18th, 2009, 10:18 PM
When did we all go back to hieroglyphics?


Hey Man, it's One World Order time, dig it! As we is in a tower of babel condition, glyphs are IT!

patscc
February 19th, 2009, 08:21 AM
Druid6900 said...Read a Mac service manual some day

...preeettty colors....

patscc

Terry Yager
February 19th, 2009, 10:10 AM
When did we all go back to hieroglyphics?

When illiterates began buying computers and expected to somehow be able to use them. It all started with st00pit ICONS and pointy-clicky GUIs. I have a helluva time trying to de-cypher most icons. There are some on my cars, home appliances, etc that I still haven't figgered out yet...they might as well be cuneiform...

--T

BG101
February 24th, 2009, 11:55 AM
There is one word which says it all.

TROUBLESHOOT.

So, you have trouble and you shoot it?? I REALLY hate that term. It skirts right around the real issue and makes it look like something someone else will do for you.

This is the replacement for the Correct term, FAULT DIAGNOSIS.

But we are not exactly encouraged to do that these days are we, the manufacturers have no interest in people keeping "yesterday's product" working as there is no profit in it for them.

The TV service trade is practically dead and the only way the surviving service centres can make ends meet is to fix something for less money than a new product can be bought for, which of course is made in China and therefore not generating local revenue anyway.

Unfortunately technical skills are under threat of extinction, thankfully there are some people left trying to keep it alive.

It will be a very sad day when you can no longer keep things working, only replace them with new ones, because a perfectly good computer is rendered useless for want of 1 basic component and someone with the skills to find the fault and repair it :(

Icons and GUIs have their place, but surely having direct control over what we are doing with our computers has a place too? Compare Linux (and DOS) with the all-pervasive and closed-door experience of Windows ... you can LOOK but you can not TOUCH ;)


BG

I needed that rant

frozenfire75i
February 24th, 2009, 12:06 PM
Computers don't mean anything to 99.5% of the world, they are just an appliance anymore, they treat computers the same as you would a toaster, coffeepot or DVD player, when it don’t work anymore. Just throw it away and get a new one.

So dishearten, but true, I had an 800$ LCD T.V go bad, I was told there was hardly any parts for them an if you did find them you had to wait 8 weeks for it. I wonder why that is, they expect you to go out buy it again. And make their profit again!

Everything has been turned in to a consumable
/

rebeltaz
February 24th, 2009, 12:54 PM
The TV service trade is practically dead and the only way the surviving service centres can make ends meet is to fix something for less money than a new product can be bought for, which of course is made in China and therefore not generating local revenue anyway.

Unfortunately technical skills are under threat of extinction, thankfully there are some people left trying to keep it alive.

Icons and GUIs have their place, but surely having direct control over what we are doing with our computers has a place too? Compare Linux (and DOS) with the all-pervasive and closed-door experience of Windows ... you can LOOK but you can not TOUCH ;)


As a TV service technician myself - AMEN BROTHER! And of the technicians that are left, I appear to be one of the few who will actually troubleshoot do to the component level. I get calls from customers all the time with the same situation - Anothe so-called tech has told them that their two year old TV is either unrepairable because "parts are no longer available" or the cost of a complete board would be economically prohibitive. 9 times out of ten I can repair the set with a handful of off the shelf components and the customer is ecstatic.

I guess I shouldn't complain, as it's these idiots (the other so-called techs) that keep me in business. It just bothers me that the world has become disposable and that before long, there won't be anyone left with the knowledge to repair it when it finally breaks down.

That's it BG101 - get me started, why don't you!

BTW - as for GUIs, that's why I run Linux on my new laptop and DOS on one of my (many) main systems....

Druid6900
February 24th, 2009, 01:03 PM
Yes, I too, have to thank the hordes to useless "technicians" out there for a lot of my livlihood.

I've had people bring me boxes with their computer disassembled that have been sitting in a computer store for 3 months.

The problem? After about 10 minutes, the CPU fan would stop running and the CPU would shut down. Three months and they couldn't find that.

Unknown_K
February 24th, 2009, 02:10 PM
Technicians went out of style because companies do not want their stuff fixed, just replaced with something new. That and everything is done these days with special diagnostic and calibration software that is not allowed out of the factory service center.

Some people just don't think anymore, I recall a retired electrical engineer telling me a monitor I was looking at would not work because parts were missing from it. He looked it over for his friend (17" LCD, analog VGA) and said it was not fixable and I told them instead of scrapping it I wanted it. The only thing wrong is a couple 3 leg chips were shorted and a few dollars later it works fine, the missing parts he was looking at were just for a DVI option that was not installed. The first thing I look for on dead equipment are bad capacitors and signs of overheating. You have no idea how many people ditch computers because hair and dust have clogged the video card fan or cpu fan and the system overheats after 30+ minutes of use. Or a couple capacitors have bulged/leaked and need replaced. I am still amazed when I see people who know better trying to make a part/card fit where it shoulf not.

The real sad thing is people with the skills to fix equipment are pretty much worthless in todays society, they are looked at like lepers. We are supposed to use something for a couple years and buy another one, even if the fix is $3 worht of parts and 5 minutes of soldering. I recall when LCD monitors came out people were telling me to ditch my old trinitrons and get a new $800 LCD for gaming, even when the colors sucked and the graphics streeked. Why did manufacturers ditch CRT to go with LCD, it was because there was no profit in CRT and they could ream you on LCDs. Now that LCD is getting super cheap they will come out with something newer, more expensive, and inferior to sell you.

vwestlife
February 24th, 2009, 02:28 PM
You have no idea how many people ditch computers because hair and dust have clogged the video card fan or cpu fan and the system overheats after 30+ minutes of use. Or a couple capacitors have bulged/leaked and need replaced.
BTW, are you from the Pittsburgh area? "Needs fixed" / "needs replaced" (omitting the "to be") is a very interesting and peculiar eastern PA / western Ohio saying. :)


I am still amazed when I see people who know better trying to make a part/card fit where it shoulf not.
There's a thrift store around here that sells used electronics quite cheaply... but they part everything out before they put it on the shelf. So they have a rack full of "wall wart" power supplies, and you have to mix and match which one is supposed to go with the item you're looking it. I often see the remnants of someone's attempt to plug a 15VAC wall wart into an answering machine that was expecting 4.5VDC... and they wonder why it doesn't work!