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SS7 motherboard not working

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Reply 20 of 24, by rasz_pl

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again
>the only thing you should measure is drain-source junction
while in circuit, powered down, in diode multimeter mode, both directions

low resistance gate-source can mean blown LX1682, would result in same symptoms, testing will require desoldering to check

Open Source AT&T Globalyst/NCR/FIC 486-GAC-2 proprietary Cache Module reproduction

Reply 21 of 24, by PcBytes

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rasz_pl wrote:
again >the only thing you should measure is drain-source junction while in circuit, powered down, in diode multimeter mode, bot […]
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again
>the only thing you should measure is drain-source junction
while in circuit, powered down, in diode multimeter mode, both directions

low resistance gate-source can mean blown LX1682, would result in same symptoms, testing will require desoldering to check

Here's a photo of what I mean. Explanation on the bottom of the picture.

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"Enter at your own peril, past the bolted door..."
Main PC: i5 3470, GB B75M-D3H, 16GB RAM, 2x1TB
98SE : P3 650, Soyo SY-6BA+IV, 384MB RAM, 80GB

Reply 22 of 24, by rasz_pl

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your pinout is wrong, your conclusions are wrong, pin 1 is gate

again
>again
>>the only thing you should measure is drain-source junction
>while in circuit, powered down, in diode multimeter mode, both directions

>low resistance gate-source can mean blown LX1682, would result in same symptoms, testing will require desoldering to check

Open Source AT&T Globalyst/NCR/FIC 486-GAC-2 proprietary Cache Module reproduction

Reply 23 of 24, by PcBytes

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rasz_pl wrote:

the only thing you should measure is drain-source junction
while in circuit, powered down, in diode multimeter mode, both directions

I get infinite resistance on all FETs when I do that.

"Enter at your own peril, past the bolted door..."
Main PC: i5 3470, GB B75M-D3H, 16GB RAM, 2x1TB
98SE : P3 650, Soyo SY-6BA+IV, 384MB RAM, 80GB

Reply 24 of 24, by holoprox

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so? what are we doing now for our beloved boards?

K6BV3+/66 REV:B1 here with AMD K6-2/450AHX - gets hot (very hot indeed near it's limit of 65 C) daws 43-45watts from the wall socket (CPU is up to 28W)
tested the board with AMD K6-2/500AFX (must be 20watts but also draws 45w or even more)
recapped 12 1000uF/6.3V caps - same sh...

no beeps, test card shows no 3.3 in PCI (but someone wrote that is to be expected) shows no activity only ----
dumped my bios with TL866-II Plus - seems good (socket seemed veeery dusty, cleaned it using contact spray)

sometimes test card behaves strange - reset glows all the time

100+ retro computers on board!
50+ flightsticks!