Nooo, strong electronic burning smell...

[orange]

sorry to intrude, does anyone have capacitors list for A4000 PSU?

[slaapliedje]

Is this probably a 3.3v memory module designed for the PC run at 5V in the Amiga? This would explain the problem. Most of the 3.3v modules do accept 5V, at least for some time, until they die from the high voltage.

Interesting, I have been running these modules for a long time, several years in fact.  

http://www.amazon.com/gp/product/B009OP8G7Q?psc=1&redirect=true&ref_=oh_aui_search_detailpage

I ordered these on Oct 10th 2013, and they do state that they are 5v.

[rkidd7952]

sorry to intrude, does anyone have capacitors list for A4000 PSU?

Hi,

I posted the list from my Lite-on supply over in http://www.amiga.org/forums/showthread.php?p=796125

Robert

[mechy]

Interesting, I have been running these modules for a long time, several years in fact.  

http://www.amazon.com/gp/product/B009OP8G7Q?psc=1&redirect=true&ref_=oh_aui_search_detailpage

I ordered these on Oct 10th 2013, and they do state that they are 5v.

Thomas has good input on the module failure, but i suspect this is simply a case of a shorted dram chip. I run much dram through my simcheckII tester and have found some cases it reports chips on simms over the years as shorted. I discard them immediately.
The power draw/short that the simm pulled through the traces may of burnt one on the accelerator.

[mechy]

I don't disagree with you. When the A4000 was designed it was a standard, if low cost PSU for the time. It's not like Commodore were breaking new ground with amazing PSU tech.

And I agree with the recapping of the original PSU and while you're at it, putting in a quieter fan.
I just found it a lot easier to put in a modern, manufactured in this century, high quality PSU. Only a few OEMs make a SFX and/or TFX PSU and they are reputable brands and the PSUs are generally of the 80+ certified variety, and run extremely quiet.

Whilst it is true that ATX PSUs do place more focus on 12V, the 80+ have solid 5V performance.

You clearly agree that good clean power is important. You can get it by improving the original A4000 PSU or by getting a brand spanking new SFF PSU.


I wasn't implying that your PSU was dead. What on first glance is a regular running PSU can still be a culprit for many things that go wrong with one's rig.

I'm not saying you must buy a new PSU. But I would at the very least recap it as per mechy's inclination.

Don't want to hijack the thread,but i dont think you realize that skynet and liteon were 2 of the major psu makers since the early pc days. Commodore had nothing to do with the psu design other than passing them specs for size, cooling,  and power required. These are off the shelf standard pc psu's just like any pc used. The same basic power supply scheme is still the same today, the only difference is switching parts with less gate resistance and such and some run higher switching frequencies which is debateably better. sff,matx,tfx, it doesnt matter all the same designs and i can give you half a dozen examples of junk brands. Even some of the OEM brands fail and have substandard caps,poor filtering,horrible ripple,and shared rails. You are kidding yourself and others if you think new psu's are superior(well very few are).
Many a4000's simply fail because of overheating caused by fans being dirty,neglected or bad. When changing to a quiet fan the CFM needs to be adhered to since it also cools the entire case. Never speed reduce a 4000 psu fan.

[delshay]

Is this probably a 3.3v memory module designed for the PC run at 5V in the Amiga? This would explain the problem. Most of the 3.3v modules do accept 5V, at least for some time, until they die from the high voltage.

3.3v simms normally have a regulator, and it is this that normally go's faulty first when memory is pushed to hard.

Overvolting memory is nothing new, even today manufacture(s) are still overvolting the chips. This is something I have been working on, custom private high performance memory module that operate within the JEDEC standard voltage.

[slaapliedje]

So the question is what should I do here...

Stachu told me;

"Each defect is different. Sorry, but I cannot give you any quotation.
In general after such accident the repair is
1) quite easy (burned track).
Or
2) Impossible to repair - programmable chips are gone.

Case one repair is roughly 30 to 200EUR + postage back
Case 2 is not repairable at all."

So the question is, should I A) call it dead, and try to search out a PPC (whether there is a new product, or find one on Amibay (looks like there are a few on there in the 1100 Euro range... ugh) try to find an 060 to replace this one (almost as much from what I can see), or B) go ahead and see if he can bring it back to life.  I inspected it semi-decently and didn't see any other burn marks on it, but I'm not exactly an expert.

slaapliedje

[QuikSanz]

Don't want to hijack the thread,but i dont think you realize that skynet and liteon were 2 of the major psu makers since the early pc days. Commodore had nothing to do with the psu design other than passing them specs for size, cooling,  and power required. These are off the shelf standard pc psu's just like any pc used. The same basic power supply scheme is still the same today, the only difference is switching parts with less gate resistance and such and some run higher switching frequencies which is debateably better. sff,matx,tfx, it doesnt matter all the same designs and i can give you half a dozen examples of junk brands. Even some of the OEM brands fail and have substandard caps,poor filtering,horrible ripple,and shared rails. You are kidding yourself and others if you think new psu's are superior(well very few are).
Many a4000's simply fail because of overheating caused by fans being dirty,neglected or bad. When changing to a quiet fan the CFM needs to be adhered to since it also cools the entire case. Never speed reduce a 4000 psu fan.

I Agree! The original supplies are almost bullet proof, but, must be cared for every 20 to 25 years or so, recap it. An ounce of prevention......

[slaapliedje]

Oh my god, forgot how slow the 68040 is.  The whole system takes 4 times as long to boot, and I can actually see the parts of the screen where things are going to load.

AmikitReal is definitely meant for something more than the stock 68040/25.

Still wondering if I should try to get this fixed, wait until maybe someone will pop up and say "Hey buy this project that has been in the works for 15 years!" or try to find a PPC and/or another 68060 to replace this one....  I do have a copy of AmigaOS 4.1 FE for classics that I could install on it if I got the PPC (been playing around with it in FS-UAE, and it's pretty nice, reminds me of an extremely patched version of 3.9.

Suggestions?

slaapliedje

[Oldsmobile_Mike]

30-200 doesn't sound bad to me. I'd try to get it fixed, if it were me. Good luck!

[QuikSanz]

Oh my god, forgot how slow the 68040 is.  The whole system takes 4 times as long to boot, and I can actually see the parts of the screen where things are going to load.

AmikitReal is definitely meant for something more than the stock 68040/25.

Still wondering if I should try to get this fixed, wait until maybe someone will pop up and say "Hey buy this project that has been in the works for 15 years!" or try to find a PPC and/or another 68060 to replace this one....  I do have a copy of AmigaOS 4.1 FE for classics that I could install on it if I got the PPC (been playing around with it in FS-UAE, and it's pretty nice, reminds me of an extremely patched version of 3.9.

Suggestions?

slaapliedje

I know what you mean. Going back to 030/40 from 060/50 was bad enough on my A2000. now just a games machine. The A4000T gets the most attention now.

[slaapliedje]

Yeah, losing the 128mb of ram on the accelerator hurt as well.  Though oddly it was only showing part of my ram, I should have 272mb or so (128mb Zorram, 128mb radeon, and 16mb of fast).  I'll have to look again and see what's up with that.)

Worse part is, I started this whole process by trying to get the mouse wheel working on my new amiga mouse... and it still doesn't work!

Bah, no luck for me this month.

slaapliedje

[delshay]

Err I like to point out that some user(s) here do have 3.3v simm(s), but probably don't realize they are 3.3v simm(s).

It's the Micron MT4LC16M4H9 chips, you will find this on 64 & 128MB simms. see PDF docs.

Test here has shown their can fail in a very short time if voltage exceeds 5.5v, but at 5v no problems has been detected. A good sign there is a problem, the chip will get very hot to a point where you can't hold your finger on the chip.

ALL MODIFCATION AT YOUR OWN RISK.

[mechy]

Err I like to point out that some user(s) here do have 3.3v simm(s), but probably don't realize they are 3.3v simm(s).

It's the Micron MT4LC16M4H9 chips, you will find this on 64 & 128MB simms. see PDF docs.

Test here has shown their can fail in a very short time if voltage exceeds 5.5v, but at 5v no problems has been detected. A good sign there is a problem, the chip will get very hot to a point where you can't hold your finger on the chip.

ALL MODIFCATION AT YOUR OWN RISK.

Many simms are 5v tolerant even thought the datasheets dont list them as so, I have run a 128Mb 3.3v simm in a csa derringer for almost 6 years now. The simm doesnt show any heating and has always worked flawless, but as you say,buyer beware. I still think he had a chip short and draw excess current since only one of them fried and it took so long.

[slaapliedje]

Many simms are 5v tolerant even thought the datasheets dont list them as so, I have run a 128Mb 3.3v simm in a csa derringer for almost 6 years now. The simm doesnt show any heating and has always worked flawless, but as you say,buyer beware. I still think he had a chip short and draw excess current since only one of them fried and it took so long.

That'd be my guess as well, or that it shorted out further down and went up and dissipated through the burned chip.  Everything except the accelerator is still working fine.  Stachu should have it in a few days.

slaapliedje

[delshay]

EDO/SDRAM/DDR1/DDR2

Voltage & timings plays a very important role here across "all" types of memory modules. In a Dual Channel configuration sometimes one memory module out of the two requires 0.10v higher than the other.

Here this is considered as a fault, but is not a real fault, it just one of the two memory modules require 0.10v extra voltage to operate correctly, but this drives up overall voltage,  when clearly one memory module can operate at a lower voltage than the other. So here if one of the two memory modules requires an extra 0.10v, it is automatically rejected by default.

Here all types of high performance memory modules voltage is kept to a minimum and some will fall back into the JEDEC standard with the same or better performance (speed).      

For Simms, its the timing that is critical & voltage plays a less important role.