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Amiga computer related discussion => Amiga Hardware Issues and discussion => Topic started by: iamaboringperson on September 13, 2003, 04:10:46 AM
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I find that my A4000T keeps restarting.
And the power (P8 & P9) cables get very hot, the red wires especialy are getting hot, and on the connector the plastic arount the pins that are connected to the red wires is melting and burning and turning black/brown. It's really not a pretty sight.
I'm wondering if you could tell me where the problem is.
I will be replacing the PSU + wires. But That might only be a short term solution.
The problem only seems to be at the connector end. Could it just be cruddy connectors?
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Do you have a CPPC by any chance? This is a common problem of that model of CPU card.
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It's just commodores ####ty old A3640 :-(
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Hmm, if your connectors were crap then you'd get less current and so less heat. Something in your system is drawing too much power. They tend to do that when they get too old.
I suppose you could always polish the connector pins a bit (carefully!) and get new power feed cables. If you cpu card has a fan you might be able to take some of the load off the motherboard by powering the fan straight from the PSU (if it's not already).
I have this problem with my Amiga too, and I never really managed to fix it. Without the two extra powerfeeds (one in the fan, one in the floppy power feed), my Amiga probably wouldn't work at all. :-(
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CPPC is JUNK! A3640 mil spec is the best accelerator for your Amiga 2000HD Professional!
;-)
Do you have a CPPC by any chance? This is a common problem of that model of CPU card.
@KennyR -
Do they give a reason for this? (Although it does sound like a lose connection problem to me)
@iamaboringperson -
Good to hear you're replacing the PS but be careful, and in the meantime, keep a fire extinguisher nearby! :-o
Good luck,
Mike
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CPPC is JUNK! A3640 mil spec is the best accelerator for your Amiga 2000HD Professional!
:lol:
Good to hear you're replacing the PS but be careful, and in the meantime, keep a fire extinguisher nearby!
Don't worry, I've had plenty of experience with AT PSU's ;-) (And no, I wont be opening it :-/ )
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Oldsmobile_Mike wrote:
Do they give a reason for this? (Although it does sound like a lose connection problem to me)
I guess it's because the Amiga was never meant to power CPUs as powerful as the PPC, and the CPPC has one and a 68k. The problem is worst on 040+233. Some people don't have it at all though, maybe it only happens with earlier produced boards. And sometimes they don't have it at first but it comes on as the board gets older. It's worse on BPPC. Mine started misbehaving some 2 years after I got it - loss of picture, crashes, melted cables, etc.
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If the system is drawing current through
connectors that can't handle the load, they can
indeed get too hot and melt the plastic
connector bodies.
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As a starting point, my advice would be to first
replace any dodgy connectors with nice thick
ones, any wires that may not be up to the task
(too thin) and check all grounds/etc.
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While not computer related, this link (http://www.interfire.org/res_file/fseab_tv.asp) contains a short summary on something with which I have personal experience, related to power connectors and fires. Since then, all replacement alternators of the model used by Ford at the time contain an integrated (hard-wired, not removable) power connector.
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hmm, Thanks for the link Oldsmobile_Mike.
I think I will replace my PSU now. :-)
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@KennyR
Hmm, if your connectors were crap then you'd get less current and so less heat. Something in your system is drawing too much power. They tend to do that when they get too old.
Actually, you are right that the m/b will get less current but it means that a dodgy connection with high contact resistance will be dropping more voltage, wasting power/creating heat.
Cheers,
- Paul
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I had exactly the same problem with my P8 & P9 connectors. They were clearly running too hot in places and were turning the plastic connector block a dark brown colour.
The problem is the internal blade connections within P8/P9. They seem to be too maleable for my liking and are easily displaced . The result is too much juice going through too small an area. It gets hot.
You can fix this by carefully releasing the internal connectors one at a time and making sure there's plenty of contact with the mobo pins.
You need a very thin/rigid tool to release the retaining tang on the connectors. They readily pull out of the socket with a little bit of practice. Make sure the retaining tangs are repositioned so they 'bite' when the refurbished blades are pushed back.
I've had no problems since making this little fix.
Cheers,
JaX
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? you may want to check the wall socket where your cable plugs into the wall, many times a loose connection there will cause small unnoticed electric arc that can cause problems like that. electricity needs good firm connections. but the red wires if i remember right are( 5+ volts ) and could be a indication that something is pulling to much power,so i would guess that the power supply has a weak compacitor or failing, and changing the power as you suggested is the best first responce.
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no no and thrice no! i thought this was only me!
the A4000T comes with an AT type power connector, and by design the actuall contact area between the pins off the mainboard, and the connector "shoe" in the plug is a very small area. (about 2mm by the width of a human hair)
loading this up with power sucking cards like 040's or (in my case) my PPC card and other various zorro cards, (see signiture below) would cause the plug to heat up due to the amount of current required by the mainboard to support all these devices running through a very small contact area.
hence power lead plugs melting burning and discolouration. i originally thought this was a software fault as it kept crashing, then after a couple of months after buying my CS-PPC it wouldn't boot at all. replaced the power supply, all fine and dandy for a while, then after a few months, same problem. took the machine to pieces to see what was up. and looked at the power plugs. burnt out on the 5 volt lines (the red leads if memory serves me correctly), to the point that the connectors in the plugs had burnt away completely.
fortunatly the mainboard was fine, i just wasn't too happy about going back to a 25Mhz EC030 and IDE drives for the sake of power problems. so i ended up cutting off the plugs, stripping the ends of the wires, and jamming them in the back of end respective pin on the mainboard. nice wide connection area. worked a treat forever. (till i sold the machine)
a more permanent solution would be to solder some flying leads off of the mainboard power connector, screwed into a block connector. the other side of the block connector would have the lines from the power supply screwed into it.
but yes. a heavily loaded A4000T mainboard will overload the AT power connecter. sad but true.
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REGARDLESS...i'd suggest you get a GFCI and a CO2 fireextinguisher to put near the comp..
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loading this up with power sucking cards like 040's or (in my case) my PPC card and other various zorro cards, (see signiture below) would cause the plug to heat up due to the amount of current required by the mainboard to support all these devices running through a very small contact area.
That shouldn't be.
It's the standard PSU in the A4000T, my 'accelerator' card is the old Commodore one that comes as standard, and I only currently have one zorro card, one hdd, and no cd drive etc...
My x86 machine has the same wattage PSU, however it has a faster and less efficient cpu, usually has 2 cards, and a whole bunch of other stuff.
If a 250W PSU is enough for your average Pentium machine, I'm quite certain it's good enough for my amiga.
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sir_inferno wrote:
REGARDLESS...i'd suggest you get a GFCI and a CO2 fireextinguisher to put near the comp..
I might even take your advice ;-)
I've recieved another PSU, and I assumed it would come with a switch! No swich, my A4000T PSU's switch is soldered onto the leads, so I could desoler those and then just plug these other wires on. Or I'll just buy another switch.
The scary part for me is working with high voltages, even though I know all I have to do is match up the colors to the correct pins, the fact that it's high voltage scares the #### out of me(been electricuted before), however I suppose the worst I can do is 'hot wire' the thing ;-)
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Oh. I forgot to mention, that I took pictures of the burnt connectors, and I might upload them soon, so that we may discuss what went on even further.
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"been electricuted before"
Man you have been electricuted and are still posting here. Now that is a shock! :-o
The low voltages out of a ps will not hurt you. The higher voltages going in (lin in) and found inside the ps will. Just don't open the ps case and you will be ok.
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Man you have been electricuted and are still posting here. Now that is a shock!
heh
That's not by mains voltages though. It still is an unpleasant feeling :-(
The low voltages out of a ps will not hurt you. The higher voltages going in (lin in) and found inside the ps will. Just don't open the ps case and you will be ok.
I'm not worried by the 5/12 volt ones, it's the wires to the switch that worry me!
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Molex style connectors were never meant to carry as much current as that. The connections are of a poor quality and your wires start to over heat. I suppose you could parellel your wires so that there would be 2 carrying the same current as one before. I am not familiar with your exact model but it seems you are not the only one to have the problem. I see this often at work on equipment not meant to survive the rigors of the factory floor. I have replaced connectors with high temp resistance. Ventilation also makes a diiference.
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@Ima
I am pretty sure, as may people suggest, excessive current loading is the problem. If you are so inclined, I would suggest attempting to locate any other places you might be able to feed power into the motherboard in addition to the normal connector.
On an A1200 this is easy since you have the floppy power point, but I expect an A4K mobo is trickier.
Has anybody managed to add an additional power feed to an A4K motherboard?
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ok , dunno if this will help.
i once had 2x 300 watt psu's in my amiga (both was atx)
why? , because my hdd's keept falling out (u know the sound) ..
so i added one more (and my miggy is pretty souped up).
i had 2 psu's...belived that would cure my problems..., and sure it did until the weird things started to happen.
THE fan on psu 1 died, just stopped to rotate (it was powering a hd and 2 fine..
so i replaced Psu1 with a new one.
Then Fan on PSU 2 died , just like psu 1 did , so then i belived that having 2 psu's in one tower aint a good idea.
but i got another psu. and a few months later both was dead.
note that psu 1 got replaced by a new one and the new one didnt die until after psu 2 had died.
any connection? .
i use the atx converter for the RBM towerhawk.
anyway i never blew any psu with the adapter when i had 1 psu connected.
later on (now) i use 1x AT psu as i removed my atx stuff when i got an mediator , i tried with 2 psu's now also, but the psu dies (fan stops to rotate)
(and it max deliver powerenough for maybe 2 hdd's ... or else it will just die....crap)
maybe its of the same problem? , system not meant to be powered like this? , maybe its the tower GROUND ? ...oh well i dont know and i find it very mysterious.
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To iamaboringperson:
I find that my A4000T keeps restarting.
Now do you see why I have 3 Amiga 2000 Series computers and not a 3000 or 4000 model? The Amiga 4000 is not built as good as an Amiga 2000 Series computer. Commodore had lowered the quality on all of the Amiga models AFTER the Amiga 2000 Series, but they refused to lower the quality on their Flagship computer. :-P
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You tell 'em!! :lol:
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DoomMaster wrote:
To iamaboringperson:
I find that my A4000T keeps restarting.
Now do you see why I have 3 Amiga 2000 Series computers and not a 3000 or 4000 model? The Amiga 4000 is not built as good as an Amiga 2000 Series computer. Commodore had lowered the quality on all of the Amiga models AFTER the Amiga 2000 Series, but they refused to lower the quality on their Flagship computer. :-P
Who asked you, "DoomMaster"?
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ok, lets see how the A2000 PSU does with the current draw i had on my A4000. i used to own an A2000, and sure, its nice, and i liked the design (especially the mouse keyboard and joystick ports at the front of the case...) just... erm well, you couldn't put a Zorro3 full motion video capture card in it and stuff video data to your hard disk(s) at 8-12Mb a second do get full DVD quality and expect your sound card to be able to stream sound to and from (for performance's sake) a drive on another scsi bus (bandwidth of around 8Mb a second) at the same time as WELL as generating two cybergraphics displays without a hiccup. sorry whats that? a 16 bit bus? memory limits? non ppc? non ultra wide scsi? no onboard IDE for cheap cd drives? functionality my friend, functionality :-D
ok so the A4000T was a nice machine, but could have been better thought out (i mean what was the point of having seperate video and I/O modules? why not have all the connectors on the back like normal and use the space for a couple of extra zorro slots? ;-)
but if your entire arguement is based on the quality of the CASE the machine comes in, not to mention basic functionality which is why i had an A4000T in the first place then so be it. i think we all know that the A2000 was designed and build when commodore had some cash, and the A4000 was the end of the line so the cash wasn't so available. so enuff. please. i just don't want to hear another 2000 vs 4000 argument. :-)
anyway, to re-iterate my original point. the A4000T mainboard power connector is FINE it can take lots and lots of nice juicy current. :-D
its just the AT plug that bolts in is a pants PC design. :-(
so like i said. directly solder some leads to the power connector so you get a nice connection area onto the pins, and you will be fine. :-)
DO NOT do as i did and try to power the cyberstorm directly using an unregulated 5 volt line from the power supply to the cyberstorms 5Volt fan connector. everything went dark and i nearly s##t myself thinking i'd poped about a grands worth of kit. so went outside to have a smoke and calm down, came back, powered it on without the fan connector and all good. *phew*
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watch out for your solder though, it has to be pretty good quality stuff, otherwise you might just find a silver liquid dripping out your psu ontoyour tv insides :-D
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Done it! :-D
I've replaced the PSU, connected the cables, and I have even replaced(and connected) the switch! :-)))
I was scared as hell doing this, and I switched it on with some anxiety, however I'm glad it's done now.
I've had the thing going for several minutes, and all looks well! :-D
--Edit: I might upload some pics of the connectors soon
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To illistrate:
(http://www.amiga.org/gallery/images/545/1_1622.jpg)
Note that it's only the +5V lines... very strange
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by sir_inferno on 2003/10/30 21:45:50
REGARDLESS...i'd suggest you get a GFCI and a CO2 fireextinguisher to put near the comp..
Note that a CO2 extingisher can wipe/corrupt any magnetic media. (I don't know the technical reason why, it is what I was told at work! :-o )