How to check bridges on a motherboard?

Question

Iron

Save urgently!))
One person told me that bridges burned down on the motherboard (or on the way to another world).
How can you check this with only straight arms), desire and a multimeter? From hardware, there are only 2 power supplies, this same motherboard, 3 video cards (one of them is 100% working, this system was once launched on it) and a processor and operative to it.
By the way, the board is old, it has all sorts of LPT and COM connectors, in addition to USB, so you can (maybe) observe some diagnostic signals on them

Answer 1

hmm .. well, the north bridge is slots for ddr. memory does not see - the north bridge is out. the northbridge also drives the video card slot. the southbridge rules everything else - pci slots, connectors on the motherboard such as ide, sata, usb, lan, audio

Answer 2

What kind of mother? Disconnect all peripherals, video and memory from the motherboard with the exception of the processor, connect the speaker. Check: resistance between RESET and common, USB D+, D- and common. Try to put an eraser under the bridge from the bottom of the motherboard and press the radiator to the board CAREFULLY WITHOUT WARPING and try to turn it on. Does the speaker make sounds? What are the voltages on the processor, memory, etc.?

Answer 3

buy a POST-diagnostician or pour water on it and run it. if it does not start, the bridges are definitely dead

Answer 4

POST карта нужна, да и то не факт что покажет "проблема в мосте".