Old Packard Bell Motherboard Problems

[astutehorse]

Good evening,
I've dug out this old machine that has been in the attic for a long time and tried to see if it still works. Upon turning the machine on the PSU will start up and the fan attached will start spinning, but nothing is output to the display and the lights on the front of the machine do not light up. When the machine is turned off using the button on the front of the machine the HDD light will flash once before the PSU goes silent.

So far I've changed out the RAM, plugged in a fan to see if the PSU was defective, it powers the fan so I'd assume it is supplying power to the the motherboard. I've attached 3 photos and I'm hoping that someone would be able to identify the motherboard . In the 3rd photo I have taken a close up of what I believe to be the problem, it looks like something is missing, I'm also hoping someone can identify which board it is and hope it's fixable.

I have tried to work out which motherboard was in the machine but currently have no idea,

This is the part I believe is causing the issue, it looks like something is missing within the circles and there is some bent metal there as if something has been pulled off. (I hope I'm wrong in this assumption or that it can be rectified)

Any help would be greatly appreciated

 

[R_1]

Picture 2: you need another stick of RAM. those are SIMMs EDO or FPRAM, you need two to make a bank of memory, system will only boot with two sticks. you may want to change the BIOS battery as well. they do not last forever.


ah memories...

 

[ko888]

Picture 3 shows two missing electrolytic capacitors that were ripped off the motherboard.

 

[astutehorse]

Picture 3 shows two missing electrolytic capacitors that were ripped off the motherboard.

This sounds reassuring, I'm hoping that these are possible to replace and that they need to match the same as what has been ripped out?

 

[astutehorse]

Picture 2: you need another stick of RAM. those are SIMMs EDO or FPRAM, you need two to make a bank of memory, system will only boot with two sticks. you may want to change the BIOS battery as well. they do not last forever.


ah memories...

I do have quite a few of them, I'll add a few more. I'll definitely grab a new battery for it surprisingly I'd completely forgotten to check that , I do remember using the machine when I was young and would love to get it running again.

 

[ko888]

Picture 3 shows two missing electrolytic capacitors that were ripped off the motherboard.

This sounds reassuring, I'm hoping that these are possible to replace and that they need to match the same as what has been ripped out?

If you know what the capcitance and voltage values are, of the missing capacitors, they can be easily replaced.

 

[BFG-9000]

That motherboard was made by Intel and called the Advanced/MN-A. The "A" variant was very similar to the more common MN with the notable difference of having a slot for a COAST module instead of cache chips soldered to the board.

Without L2 cache, once the 16kB of L1 on the processor is exhausted (your board only has a single phase VRM and the socket for an external VRM module isn't even soldered on so we know it's probably not the 32kB MMX, although a 233MMX chip will actually run in this board if you don't mind blasting it with 3.3v instead of 2.8v), programs will execute directly from the asynchronous EDO RAM which @ 70ns operates at an effective speed of 14MHz. That provides a main memory speed no faster than USB 2.0 today! But then if you don't have L2 cache anyway, you won't mind exceeding the 64MB cacheable limit hardwired into the 430FX chipset.

Back then, Intel were noted for making excellent motherboards that had remarkably few electrolytic caps on them, which should be good for durability. Yours managed to get its only two large ones torn off.

 

[astutehorse]

That motherboard was made by Intel and called the Advanced/MN-A. The "A" variant was very similar to the more common MN with the notable difference of having a slot for a COAST module instead of cache chips soldered to the board.

Without L2 cache, once the 16kB of L1 on the processor is exhausted (your board only has a single phase VRM and the socket for an external VRM module isn't even soldered on so we know it's probably not the 32kB MMX, although a 233MMX chip will actually run in this board if you don't mind blasting it with 3.3v instead of 2.8v), programs will execute directly from the asynchronous EDO RAM which @ 70ns operates at an effective speed of 14MHz. That provides a main memory speed no faster than USB 2.0 today! But then if you don't have L2 cache anyway, you won't mind exceeding the 64MB cacheable limit hardwired into the 430FX chipset.

Back then, Intel were noted for making excellent motherboards that had remarkably few electrolytic caps on them, which should be good for durability. Yours managed to get its only two large ones torn off.

Thanks for the information, I'm pretty dedicated to try and get this working again, but can't for love nor money find an image or information online what the capacitors might be. I'm working today but the hunt will begin again tonight, I reckon I'm going to have to find someone that still owns a machine with this board in to confirm the capacitors for me.

 

[BFG-9000]

I have 3 of them in storage and looked at them. All have Nichicon 12x25mm caps there. The one closer to the CPU is 2200mF 10v, and the other one is 1500mF 16v. Note that your board labels the (+) terminal--instead of having the usual white stripe on the (-) side to match the white stripe on the cap.

They are smoothing caps so low ESR matters more than the actual value, and if you want to stick with Nichicon then HZ. HC, HM, or HN series would be fine. The 10v one will see a maximum of 3.45v and the 16v one 5.25v, but the original values were derated to improve ESR and lifespan.

Looks like you could also use a pair of 512kB SOJ chips (256Kx16) to upgrade the onboard graphics to 2MB. That way you could run 800x600 in true color, or 1024x768 in 65k colors. Or use a 4MB+ PCI card to run higher than that. Your "Multi-media" system should've come with a sound card and CD-ROM drive.

A 256kB synchronous pipeline-burst COAST module would let your Pentium-1 run faster than a speedy 486.

And the largest HDD these could accept (without dreaded drive-overlay software) was 8.4GB. Nowadays you'd just use a cheap CompactFlash-to-IDE adapter to make a tiny SSD, instead of trying to hunt down little HDDs.

 

[astutehorse]

Thank you all for the help it's really appreciated, this evening I'll be looking to Amazon/EBay for a suitable replacement

 

[BFG-9000]

If you want to see what the caps look like installed, the Packard Bell version of that motherboard is called the "PB640." It differs in some minor ways, most notably the ATI graphics chip is replaced with a Cirrus Logic one that unfortunately cannot do 24-bit color, only 32-bit which takes more memory.

 

[astutehorse]

If you want to see what the caps look like installed, the Packard Bell version of that motherboard is called the "PB640." It differs in some minor ways, most notably the ATI graphics chip is replaced with a Cirrus Logic one that unfortunately cannot do 24-bit color, only 32-bit which takes more memory.

Cheers the capacitors have been replaced and the computer successfully booted to BIOS, now just need a working keyboard and mouse