Chaintech 486SPM M104 problem \ VOGONS

Chaintech 486SPM M104 problem

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First post, by i2lgames

Posted on 2024-08-10, 20:02

i2lgames Offline

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Joined: 2003-11-14, 17:20

Hey guys! Got a Chaintech 486SPM M104 with a strange problem, the keyboard wont work.
I checked every connection and all seem fine. The fuses are fine. I double checked all the connections, even from the ps/2 mouse header. There is continuity to the keyboard controller and the controller was tested to be good on another system. I replaced the din connector and still the same problem. The motherboard post, counts all memory. I don't get a keyboard not found error, just press F1 to enter bios. If i remove the keyboard then i get a keyboard not present error. Can you please direct me to something else?

Thank you.

Reply 1 of 5, by majestyk

Posted on 2024-08-10, 20:12

majestyk Offline

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Make sure the oscillator X1 doesn´t short any of the traces underneath.
And triple-check the 6-7 thin traces and vias under the battery plus the connections between the keyboard data and clock pins and the inverters (U30) and from there to the KBC.

Reply 2 of 5, by MikeSG

Posted on 2024-08-11, 05:39

MikeSG Offline

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Corrosion under keyboard controller, or bad socket connection

Reply 3 of 5, by i2lgames

Posted on 2024-08-11, 10:56

i2lgames Offline

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Posts: 77
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majestyk wrote on 2024-08-10, 20:12:

Make sure the oscillator X1 doesn´t short any of the traces underneath.
And triple-check the 6-7 thin traces and vias under the battery plus the connections between the keyboard data and clock pins and the inverters (U30) and from there to the KBC.

That was it! I reconnected and works fine! Now there is another "issue". The motherboard has 8x32 cache chips + one tag. A total of 9 chips for 256kb L2 cache. The cache is reported in boot but won't be recognized in cachechk, it tells me i have only one cache! I use 2x4mb fpm for the test. The jumpers are set correct! Any advice?

Reply 4 of 5, by majestyk

Posted on 2024-08-11, 12:25

majestyk Offline

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Try setting jumper JP25 to 2-3.

Reply 5 of 5, by i2lgames

Posted on 2024-08-11, 13:36

i2lgames Offline

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Posts: 77
Joined: 2003-11-14, 17:20

majestyk wrote on 2024-08-11, 12:25:

Try setting jumper JP25 to 2-3.

That did it!
Works like a charm now!
Thank all of you guys for the help!

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