VOGONS


First post, by Mut

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Found this TK 8498F on a flea market some time ago, it was pretty cheap (4 us dollars).

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At first the board was not posting.
The board had some big scratchs on the backside and a trace near the cpu socket was broken, sadly I didn't took a picture before the repair.

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Still not booting, a pin on the memory slot was bent and causing a short circuit, fixed and finally posted!!!

Ops! Keyboard not detecting and a weird siren beep during memory count, replaced the bios and no change (I had a opti socket 3 board in the past that a corrupted bios caused a siren like beep on post)

Checked with multi meter and found the keyboard data pin (the center pin) shorted to ground. Thankfully I have the same board on my pile of working boards, so I could use it to trace the data pin.

Discovered that the keyboard data pin went straight to the pin 30 of the south bridge and pin 167 of north bridge only passing through a cap, a resistor and a bridge.
The cap and the resistor checked good, so the problem was on the south bridge or in the north bridge, in both cases it was a "game over".

So I desoldered the pin 30 of the the south bridge and kb data pin was still shorted.

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With Nothing to loose, I broke the path to the 167 pin of the north bridge (desoldering in this case wasn't a easy job).

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But the kb data path was still shorted to ground , BUT HOOOOW!!!!!

Without new ideas I checked the inoffensive bridge and just bellow found two little eyelets to the other side of the board. The bridge was shorted with those eyelets!!!!!!
Bellow is photo of the "repaired bridge".

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Resoldered the south bridge pin and repaired trace that I broke to the north bridge.

Now the board works perfectly.

Reply 3 of 3, by Mut

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Yes, it is fake cache. I have replaced with some chips from a dead motherboard and now the cache is working.

Attached the dumped bios.

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