Help Diagnosing a PIII Machine

[Anonymoose]

Heyo!
I have Dell Dimension L600R that used to work as normal, but soon it started forgetting the SD to IDE adapter and eventually would turn on but not display anything or boot. The monitor would go into sleep mode. Alright, so I did the normal tests (test wall socket, power cable, PSU, reseat ram, reseat PCI cards, etc) and everything seems to be normal. The 4 diagnostic lights on the mobo indicate a "PCI Bus Failure Has Occurred", so I checked the SIO chip (SMSC LPC47B272) and that also seems to be working (then again, I've never probed an SIO chip so maybe I did it wrong? All +3.3 Volt Supply Voltages report 3.33 exactly).

Anyways, just wanted to check with The Council to see if there's anything more I need to do. I would hate to toss the computer, it has sentimental value

https://dl.dell.com/manuals/all-products/esuprt_desktop/esuprt_dimension_desktops/dimension-l-cx_reference%20guide_en-us.pdf

https://theretroweb.com/chip/documentation/lpc47b272-6419d4c5720fc178222163.pdf

 

[acgs]

I have Dell Dimension L600R that used to work as normal, but soon it started forgetting the SD to IDE adapter and eventually would turn on but not display anything or boot. The monitor would go into sleep mode. Alright, so I did the normal tests (test wall socket, power cable, PSU, reseat ram, reseat PCI cards, etc) and everything seems to be normal.

One never knows how much data to give in the initial post regarding the problem. In this case I don't think there is enough to really point in a conclusive direction to head, but I'd start by looking carefully at all capacitors on the motherboard. I've had P3s and beyond start acting strangely and "die" on me only to see fat, misshaped capacitors on the board. (Some even were NOT misshaped very much but were scorched or cracked instead.) Replacing just those capacitors and doing nothing else brought the machine back to full functionality.

If you don't see any capacitors that look bad, you should check to be sure that there aren't any significantly hotter that the rest. (I mean hot enough to possibly burn your finger when you touch it a few minutes after you apply power to the system.)

I would hate to toss the computer, it has sentimental value

NEVER TOSS a computer if it has sentimental value! You can always get it back to functionality even if you have to gut it and replace everything inside with an emulator.

 

[Anonymoose]

Yeah, I'd love to give more info but visually nothing seems wrong. I left the motherboard on and after a while the caps weren't hot and the chips that were warm (not burning hot) were the Intel 810e and a chip labeled ICS9250BF-16. This time around though, the error lights indicated "Other Failure" (green green green orange, it has never been yellow so the orange seems to be yellow?)

 

[Al Kossow]

buy a PCI POST test card

at least it will give you a hint as to how far in the initial self-test process it gets

 

[NeXT]

Sanity check here since this was the Plague Era. You said you tested the PSU but have you opened it and done a visual inspection?

The board at least uses Nichicon and Sanyo. Those were generally okay back then but I have not really needed to troubleshoot a dead PIII for quite a while.

 

[Anonymoose]

buy a PCI POST test card

at least it will give you a hint as to how far in the initial self-test process it gets

Interesting, I haven't heard of this! Is there a certain one you'd recommend?

Sanity check here since this was the Plague Era. You said you tested the PSU but have you opened it and done a visual inspection?

The board at least uses Nichicon and Sanyo. Those were generally okay back then but I have not really needed to troubleshoot a dead PIII for quite a while.

I've done the paperclip test and I've opened the PSU to blow out dust but visually it looked fine. I'm not the most technical so maybe I missed something.

 

[NeXT]

Teapos are still Teapos but you are right, there's nothing obvious in there. :/

 

[Al Kossow]

something like this should work

PC Computer BIOS Motherboard Tester Analyzer POST Code PCI ISA Diagnostic Card | eBay

Both ISA bus and PCI bus. 1 x Main diagnostic card. 1 x PC Speaker Connection Cable.

www.ebay.com

 

[NeXT]

I was going to question if that would also understand Dell POST codes but it says so in the product description that it can.
Yeah I second Al here and get one to test with.

 

[acgs]

Another physical breakdown that might be visible would be a cold solder joint on the underside of the board. I'd think it was unlikely to not have indications show up on both sides of the board, but sometimes the damage is only visible/limited to around the solder joint itself.

With the good advice @Al Kossow and @NeXT have been contributing, I didn't think to mention it before. But it's worth a look if you've already pulled the boards out anyway.

And it's unanimous, get a POST code card.

 

[GiGaBiTe]

I've done the paperclip test and I've opened the PSU to blow out dust but visually it looked fine. I'm not the most technical so maybe I missed something.

A paperclip is not a test. The only thing it will tell you is that the power supply is working enough to power on. It doesn't tell you if the power supply is actually able to output clean regulated power rails. You need an oscilloscope and multimeter to look at the outputs under a load.

I've found that power supplies from that era usually have bad capacitors, even if they don't outwardly appear bad. The ones that usually fail first are the tiny ones buried in between transformers and mosfets, because they're subject to the most heat and least amount of cooling. More rarely, the main line capacitors go bad, which cause all matter of problems.

As for the motherboard, it has SMD capacitors on it, and it's subject to the shitty 1990s SMD electrolytics that fail and leak out of their base. I would remove and replace those, because you can't really test them without destroying them, and they're cheap enough.

 

[acgs]

Alright, so I did the normal tests (test wall socket, power cable, PSU, reseat ram, reseat PCI cards, etc) and everything seems to be normal.

I've done the paperclip test and I've opened the PSU to blow out dust but visually it looked fine. I'm not the most technical so maybe I missed something.

A paperclip is not a test. The only thing it will tell you is that the power supply is working enough to power on. It doesn't tell you if the power supply is actually able to output clean regulated power rails. You need an oscilloscope and multimeter to look at the outputs under a load.

All this makes me realize that I didn't think enough about your testing of the PSU. From what's been said above, I think you probably are lacking another important piece of test equipment: a Power Supply Tester. While @GiGaBiTe's suggestion of an oscilloscope and multimeter is sound, it's probably currently beyond your "not the most technical" person standing. A proper tester will give you easily readable/understandable data for troubleshooting. Like one of these:

https://www.amazon.com/Computer-PC-Tester-Connectors-Enclosure/dp/B076CLNPPK
https://www.amazon.com/Kingwin-Computer-Supply-Tester-Digital/dp/B07VXSFXP1

As for the motherboard, it has SMD capacitors on it, and it's subject to the shitty 1990s SMD electrolytics that fail and leak out of their base. I would remove and replace those

Based on @Anonymoose's own assessment of his skills, I'd say replacing these capacitors is beyond his abilities. He'll likely need someone to change these for him if the problem is with SMDs.

 

[Anonymoose]

Based on @Anonymoose's own assessment of his skills, I'd say replacing these capacitors is beyond his abilities. He'll likely need someone to change these for him if the problem is with SMDs.

Welllll I have done the occasional capacitor replacement but SMD's I haven't done. I probably should learn eventually, as well as using an oscilloscope...

I will get the PSU tester and the bios tester though, always good to have for future diagnosing.