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386DX-33 Motherboard Issues - Dead Board?

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Smack2k

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I picked up a Biostar mb-1333/40pme-ch rev E 2 motherboard about 7-10 days ago

Finally got to trying the board and it wont post. Nothing comes up on the monitor....I think it may be dead, but I wanted to see if I am missing anything. Here's everything I tried:

Removed all RAM and tried just 1 stick of 1MB RAM in the first slot of Bank 0
Tried other known good 1 MB sticks of RAM in same slot
Reseated the DX-33 processor
Removed the 387 Math-Co I put in
Replaced the Oscillator with an 80 MHZ (Oscillator has a socket for the input, so just had to pull out the 66 MHZ one and put in the 80 MHZ chip)
Tried a DX-40 Processor that I know works.
Tried a DX-25 Processor that I know works.
Verified all Jumpers were right for cache (256K cache in it now that I put in)
Tried Multiple Power Supplies
Tried Multiple Video Cards
Verified Jumpers were set for Color Monitor (Closed Jumper)
Took Motherboard off the Chasis and Risers and placed it on a non-metal surface (to make sure it just wasnt shorting out with the case)

Am I missing anything or does it appear this thing doesnt work? The only thing I havent done is to remove the cache I put in it....but the cache chips are good and facing the same direction as the 64K that came with the board. But if that was messed up, wouldnt it just not find any cache but still post?
 
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Smack2k said:
Removed all RAM and tried just 1 stick of 1MB RAM in the first slot of Bank 0
Tried other known good 1 MB sticks of RAM in same slot
Click to expand...
One stick of RAM won't get you anywhere. You need to fully populate bank 0 with four good sticks before you can get it going.
 
Yep, on most early systems, at least two (possibly 4) sticks are required to boot. But did you get any error-code beeps with just one?
 
T-R-A said:
Yep, on most early systems, at least two (possibly 4) sticks are required to boot. But did you get any error-code beeps with just one?
Click to expand...

No beeps, nothing, power supply turns on.....then nothing....

Tried with 4 sticks just in bank 0 as well, but that did nothing as well...that was when I went down to 1....
 
Really sucks as it was said to be working.....oh well, you live and you learn....onto find another 386DX-33 board with cache.

EDIT - I have a board that works that I could put a 40 MHZ Proc in (I just need to replace / solder in an 80 MHZ oscillator that I have)....but it has no L2 Cache...

Would it run like a 33 MHZ 386DX due to no cache? 386DX-33 is what I am aiming for.
 
It all depends on your skills as a troubleshooter.

For example, is the BIOS good, or has it been trashed? What do the bus signals look like? I suspect BIOS issues because most PCs will at least beep if no memory is installed (I'm assuming that you have a speaker connected).

386s aren't nearly as bad to get working as the (much) later stuff.
 
I did have a speaker connected and there was nothing...

I have a question:

I have a board that works that I could put a 40 MHZ Proc in (I just need to replace / solder in an 80 MHZ oscillator that I have)....but it has no L2 Cache...

Would it run like a 33 MHZ 386DX due to no cache? I was told no cache can cut performance by 20 - 25% 386DX-33 is what I am aiming for.
 
You're not going to like the results without any L2 cache, even if the CPU is somewhat faster. The difference depends on the speed and amount of the cache, as well as the application.
 
Ok. That's out!

I let the bord sit turned on for about 15-20 min and the proc as well as the on board chips get warm to the touch. Not sure if that does anything to help...

Also backed the bord down to 64Kcache it came with with the same results
 
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I haven't tries the legs cleaning but I did reseat the BIOS chip
 
I'm the previous owner of that board. All I can say is I tested it to post before removing the RAM and mailing it and it posted just fine. I guess it is possible that it randomly died in transit. I do recall the board was pretty picky with RAM. I had 8 MB installed as 4 2mb SIMMS.
 
I don't know of any other PC boards that use 2MB SIMMs. Maybe it only like the oddballs? You're sure it was 2MB SIMMs?
 
Looking at this -

http://stason.org/TULARC/pc/motherb...TECH-INTERNATIONAL-CORPORATION-386-MB-38.html

http://www.elhvb.com/mobokive/archive/Biostar - Bioteq/manuals/pmb-ch.htm


the RAM configs don't mention 2 MB SIMMs, maybe it's the revision of the board taking the 2MB?

Should the BIOS chip get warm? It doesn't seem to when I boot it up and let it sit. someone mentioned cleaning the legs of the BIOS chip and the socket...isoprop for those? Or should I take some swipes with sandpaper on the legs of the chip? The socket I'd guess just isoprop. Should I try the keyboard BIOS chip to? Clean and reseat?
 
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