I hope someone can help.
I got a Cpc464 a couple of weeks ago. It was working great last night. I just tried to power the keyboard with a 5v adapter and nothing happened, no light no nothing.
Now when I plug into monitor I still get nothing. There's power getting to monitor but keyboard is utterly dead.
Have I ruined it?
Probably the +5V PSU that you have used had the polarity inverted. Please, add a picture of it.
Was the polarity wrong or something else? If not, then the CPC probably just has dirt on the power switch.
Bryce.
(http://i23.photobucket.com/albums/b357/sleazycome/Mobile%20Uploads/DSC_0701.jpg)
And was the polarity also correct?
Bryce.
Show us the other end of the cable with its connector you plugged into the cpc to check if polarity was wrong or right
(http://i23.photobucket.com/albums/b357/sleazycome/DSC_0702.jpg)
Hmmmm.... Polarity wrong. You've fried the CPC. It could be one or more ICs that have failed.
Bryce.
600 mA is a bit weak. The native CTM delivers about 1400 mA. Can that be the cause?
The previous given advice of cleaning switches etc. is a good idea.
Good luck! :)
Quote from: Bryce on 21:09, 16 April 15
Hmmmm.... Polarity wrong. You've fried the CPC. It could be one or more ICs that have failed.
Bryce.
Sounds like it's not an easy repair then.?
Guess I have ruined it.
Gutted
Even with 600mA, the polarity was wrong. Cleaning switches won't help. The RAM has most likely failed, maybe the Z80 too and who knows what else.
Bryce.
Edit: It can be fixed of course, but it can get expensive depending on what's actually damaged.
Looks like I'm back on the lookout for a 464.
Many thanks for your help
Quote from: Bryce on 21:14, 16 April 15
Even with 600mA, the polarity was wrong. ...
Upps, you posted to quick. Are you sure that wrong polarity will fry it? Does it make sense to check with a PSU or right polarity at all?
From my own experience, vintage RAM chips are still found easily. If the most fragile component of them all (as Bryce suggests), it can be easily replaced, provided you know how to solder and really want it (it may be easier to solder sockets instead and just plug the sensibles RAM chips on the sockets).
Whatever, you need a detailled diagnosis before doing something like this. RAM fail is usually detected as a frozen screen when booting : the system should power on before that.
Can you confirm the red power led stay dark ?
Bryce... is there a simple way to check the nearest discrete components near the power input ? I always thought that the failling of an only component will immediately open the circuit and protect the other ones.
A multimeter could be a good friend for this job, but we need someone familliarized with this hardware. ;D
Quote from: Bryce on 21:14, 16 April 15
Even with 600mA, the polarity was wrong. Cleaning switches won't help. The RAM has most likely failed, maybe the Z80 too and who knows what else.
Bryce.
Edit: It can be fixed of course, but it can get expensive depending on what's actually damaged.
The power led stays totally dark. It didn't even light when I plugged it into the adapter, usually I would expect it to light with the surge before failing?
From my point of view, that story is ridiculous. A least, never trash the whole unit. In case you are not able to repair, many components inside are possibly still functional and will make good spares for another failling unit. The "Gate Array" (chip labelled 40007 or 40010) being the most precious of all !
(And of course the whole plastic casing may be swapped with a less beautiful unit).
Quote from: Sleazy on 21:29, 16 April 15
Looks like I'm back on the lookout for a 464.
Many thanks for your help
Oh don't worry. I'm not binning it. Hopefully I can pick up a tarry looking but working keyboard and use this as a donor.
It's really nice and clean
I feel so stupid
You said power led stays totally dark. This means short circuit, and this is the hope! First IC that faild with reversed Vcc and got voltage down could protect the rest, but for sure some more IC'c could be damaged.
Look on Bryce's personal text please (under his photo). It's not a joke, it's Good Electronic Engineers war cry.
Thanks, I think a repair is way beyond me. I wouldn't know where to start.
I think tracking down another keyboard and if necessary using this on to spruce it up is the way forward
If you send it to me (just the main PCB, not the whole computer), then I can test it and repair whatever is actually broken (if it financially makes sense).
Bryce.
thats a great offer Bryce - thank you very much.
Where are you though? Are you actually in Sao Tome?
:D No! My confusing flag is sort of a running joke since I joined (I move islands regularly). I'm actually in Germany. I'll send you a PM with the details / address etc if you want.
Bryce.
ah cool (I'm actually surrounded by Germans as I type this).
yes please drop me a line
Many thanks to Bryce for his kind offer, I have managed to acquire another working keyboard unit for £20 delivered.
Harsh lesson learned.
Many thanks to all of you for your comments, this really is a friendly and helpful community.
Bryce, you're definitely a champ' ! :D
Quote from: Bryce on 08:42, 17 April 15
If you send it to me (just the main PCB, not the whole computer), then I can test it and repair whatever is actually broken (if it financially makes sense).
Bryce.
I don't like to see retro computers abandoned just because they are broken.
Bryce.
I am interested for the case/keyboard&tape deck if you are selling them ;D
Once my replacement has arrived I'll be offering it up on here - wanna wait to see condition of replacement first.
So replacement turned up.....
and it doesnt work! just a blank screen (power light comes on and monitor recognises input but nothing displayed).
I'm not having much luck.
(https://fbcdn-sphotos-h-a.akamaihd.net/hphotos-ak-xpa1/v/t34.0-12/11178555_10153019860637182_943578125_n.jpg?oh=49bfb0d62189f7618756987b09bc5f26&oe=553CB00E&__gda__=1430034975_ef795ff7cd0e653941dc800faa745dfc)
Aw no. :(
Also, strange place to keep your razor blades. Don't do anything silly.
Time to send BOTH PCBs over to me I suspect :(
Bryce.
Quote from: Carnivac on 13:16, 24 April 15
Aw no. :(
Also, strange place to keep your razor blades. Don't do anything silly.
Lol, I had been sorting through the cupboards in my spare room when the parcel was delivered - there was rubbish everywhere - I dont even know where the blades came from - I use an electric shaver.
Nothing beats real blades 8) ... therefore I gave up shaving... :laugh:
Best thing I've ever tried - double-edged Mercury safety razor. The old, traditional ones with the single, replaceable blade. Also: Super Iridium blade. Made in St Petersburg, blow everything else out of the water.
Off topic is off topic.
Sorry for offtopic too, but isn't is called 'terrible mistake'. While shaving this 'terrible mistakes can happen of course. So, I never heart about Iridium blades, but that sounds really awesome! :) Thanks for the hint! :)
Quote from: Gryzor on 18:05, 25 April 15
Best thing I've ever tried - double-edged Mercury safety razor. The old, traditional ones with the single, replaceable blade. Also: Super Iridium blade. Made in St Petersburg, blow everything else out of the water.
Off topic is off topic.
So why don't you use them? You were half / not shaved any time I met you :D
Bryce.
I was turning on the charm :D
Quote from: Gryzor on 12:00, 26 April 15
I was turning on the charm :D
It worked ;)
Bryce.
Awwww, you.... =)
So third cpc arrived today.. This time with a colour monitor.
It's missing the left shift key and the numeric 0. No problem I thought, I have 2 donors here.
The first cpc is the smaller mobo later revision and the second is the earlier big mobo. Both have sprung keys.
This new cpc is actually different to both! It's keys are not sprung and the keyboard is hardwired rather than the thin ribbon of the other two. The mobo says 1983 rather than 1984.
At first the broken shift was constantly on so I had to remove the presser bit. The Cpc is totally usable but isn't as pretty as I'd like.
How difficult is it to get keys that match?
On the plus side I can now play Rainbow Islands rather than Greenhow Islands!
So the broken keyboard has "High" keys and a real connector to the PCB instead of flat cable? It must be a very early CPC. Getting those keys will be difficult, but you might be able to use the top half (keys and plastic frame) of one of the working/complete keyboards with the PCB of the old keyboard?
Bryce.
Edit: Ask Gryzor if you can have some of his fridge magnets. (He'll know what that means :D )
Finally managed to get the last missing pieces and my 464 is now perfect.
Got them off a fella on Facebook who seems to fix cpcs as well as other systems. Wonder if he is a member here?
(http://i23.photobucket.com/albums/b357/sleazycome/Mobile%20Uploads/DSC_0751.jpg)
What's that monstrosity doing next to the CPC monitor? I suppose it could be worse, its only a monitor. Could be connected to an actual C64.
Quote from: EgoTrip on 16:58, 19 May 15
What's that monstrosity doing next to the CPC monitor? I suppose it could be worse, its only a monitor. Could be connected to an actual C64.
hahahahaha
actually this is one of the best monitors ;D
It's usually connected to an A600 or Cd32. It is a nice monitor. I got it for nowt last year off a mate who found it in his garage.