How to measure resistance between L1-bridges?

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--- How to measure resistance between L1-bridges?
https://www.forum-inside.de/topic.cgi?forum=14&topic=46

-- Veröffentlicht durch Lupson am 21:43 am 24. Feb. 2003

It's running 100% stably at 1701 Mhz (103*16.5) at 40 deg. Good enough for me. I'm from Sweden BTW.

/Lupson

-- Veröffentlicht durch zelan am 21:31 am 24. Feb. 2003

Happy tweaking! By the way, where are you from?

-- Veröffentlicht durch Lupson am 14:14 am 24. Feb. 2003

Wheeeehoooohooo!!! I fixed the broken bridge with a carbide(?) pen. (Normal writing pen, not an inkl pen). And it posted right away at 16.5*100 Mhz. Now let's tweak it some :)

Thanks!
/Lupson

-- Veröffentlicht durch Lupson am 12:54 am 24. Feb. 2003

It's an old Abit KT7-RAID, based on the VIA KT133 Chipset. Despite its name, it only supports 100 Mhz FSB, though one can OC it to about 105 Mhz without stability issues. Later there were the KT133A chipset and the Abit KT7A MB which had full 133 Mhz FSB support.

/Lupson

-- Veröffentlicht durch zelan am 10:33 am 24. Feb. 2003

Good to here that. But why only 100MHz FSB?

-- Veröffentlicht durch Lupson am 21:10 am 23. Feb. 2003

Okey, here goes: All L1-bridges were cut, but the middle L3-bridge -  which was supposed to be connected, wasn't connected. That is certainly due to the fact that I slipped with the razor once and cut a little bit on it by mistake. With all L3 bridges cut the multiplier is 18.5x. With my 100 Mhz FSB speed it would be 1850 Mhz on an 1800+, which may be above what it can post on. It worked fine (but hot) on 1733 mhz, but hopefully this is why it isn't posting. I'll get some silver paint and repair the bridge and then I'll tell you how it went!

Zelan - Your method worked perfectly - beep - contact. no beep - no contact!

/Lupson

-- Veröffentlicht durch Lupson am 17:02 am 20. Feb. 2003

Thank you for your answer! I'll try this approach and I'll post the results here.

/Lupson

-- Veröffentlicht durch zelan am 0:08 am 20. Feb. 2003

You can try to measure the resistance between the bridges. But I'm not sure how big the resistance may be. I would try to use the "continuity test" (don't know if that's the right word). This is a symbol in the resistance field. It looks like a cross with triangle over it. Just like the sign for a diode in a circuit diagram (I think). If there is a pass in the bridge the multimeter makes a noise. If there 's no pass, nothing happens. So you can make sure if the bridge is closed or not (Sound -> Bridge isn't cut; No sound -> Bridge is cut).

(I hope you know what I want to say...)

-- Veröffentlicht durch Lupson am 18:49 am 19. Feb. 2003

Hi everyone,

about a month ago I bought a AMD T-bred A 1800+ for my old Abit KT7-RAID Mb. After cutting all L1 bridges and two L3 bridges (to get 16.5x multi) it worked flawlessy for 4 days @ 105*16.5 Mhz. Then one morning it just refused to post. The evening before, it froze when I shut it down with the "Windows XP is shutting down" screen. I just pressed the power button for four seconds to shut the system off.

The system works just fine with my old 750 Mhz T-bird so the rest of the system isn't faulty. My theory is that one of my L1-bridges somehow has shorted again due to heatsink pressure or heat. (It didn't post at all until I had cut all L1-brides). I've tried various stuff the last few weeks, like resetting CMOS, pressing the reset button xx-times a.s.o.

Now that I've explained the background story - my plan is to use a multimeter this weekend and measure the resistance between the L1-bridges. My theory is that if any of the (presumably) cut bridges show low or nonexistant resistence, it isn't cut and I can cut a bit more with my scalpel until the resistance gets really high (i.e. - cut). Then try booting up again.

Do you processor surgeons think this is a plausible method to "repair" my poor T-bred? If anyone feel like explaining thorughly - where to place the measuring points, what values can be expected a.s.o. it would be really appreciated.

Regards,
Lupson