VOGONS


Have I killed a motherboard - no power up

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Reply 60 of 71, by rasz_pl

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strange_loop wrote on 2023-09-13, 17:21:

For PS_ON I'm getting ~5v

does it drop when connecting power_switch pins on the motherboard?

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

Reply 61 of 71, by appiah4

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strange_loop wrote on 2023-09-13, 17:21:
rasz_pl wrote on 2023-09-13, 08:07:
Seen worse still working :) certainly wont prevent Vcore supply from functioning in some capacity. Still its irrelevant because […]
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shevalier wrote on 2023-09-13, 04:00:

There is one zero missing. 😀

Seen worse still working 😀 certainly wont prevent Vcore supply from functioning in some capacity. Still its irrelevant because from what I understand power supply is not turning on at all. Its like suggesting to replace tires on a car with seized engine.

strange_loop wrote on 2023-09-13, 08:03:

failed caps can cause a total failure to power-on

no
have you tried another power supply?
diagram of the board: msi_ms-6380e_rev_0b_sch.pdf I would start on page 43 with measuring voltage on PS_ON inside ATX connector with power supply connected and while pressing power button/shorting power_button pins, also measure PW_OK voltage

Thanks for the link to the PDF. For PS_ON I'm getting ~5v, for PW_OK it's 0v.

0V on PW_OK is not ok, that should be 5V and points towards the PSU refusing to tell the motherboard to turn on because one or more of the 3.3/5/12V lines are in trouble. That could be because the 5V rail that feeds the CPU has busted caps with too high ESR. Recap the board, for the 12th time 😀

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Reply 62 of 71, by rasz_pl

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power ok is only active when psu starts

strange_loop flip that clear cmos jumper back off and hope Abit is not as stupid as they claim in the manual:
https://www.manualslib.com/manual/360295/Msi- … ?page=49#manual
"Avoid WARNING! clearing the CMOS while the system is on; it will damage the mainboard"

I never encountered a system that would self destruct with clear cmos jumper, but I did see some that would block turning on ATX PSU with clear cmos jumper set to clear.

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

Reply 63 of 71, by strange_loop

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appiah4 wrote on 2023-09-13, 20:33:
strange_loop wrote on 2023-09-13, 17:21:
rasz_pl wrote on 2023-09-13, 08:07:
Seen worse still working :) certainly wont prevent Vcore supply from functioning in some capacity. Still its irrelevant because […]
Show full quote

Seen worse still working 😀 certainly wont prevent Vcore supply from functioning in some capacity. Still its irrelevant because from what I understand power supply is not turning on at all. Its like suggesting to replace tires on a car with seized engine.

no
have you tried another power supply?
diagram of the board: msi_ms-6380e_rev_0b_sch.pdf I would start on page 43 with measuring voltage on PS_ON inside ATX connector with power supply connected and while pressing power button/shorting power_button pins, also measure PW_OK voltage

Thanks for the link to the PDF. For PS_ON I'm getting ~5v, for PW_OK it's 0v.

0V on PW_OK is not ok, that should be 5V and points towards the PSU refusing to tell the motherboard to turn on because one or more of the 3.3/5/12V lines are in trouble. That could be because the 5V rail that feeds the CPU has busted caps with too high ESR. Recap the board, for the 12th time 😀

😂 noted, caps on the way shortly.

As a general rule, I thought I'd go with one step up in terms of uF and V ratings on the replacements

Reply 64 of 71, by strange_loop

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rasz_pl wrote on 2023-09-13, 20:29:
strange_loop wrote on 2023-09-13, 17:21:

For PS_ON I'm getting ~5v

does it drop when connecting power_switch pins on the motherboard?

No, both results unaffected by switch pins, whether with a jumper or holding a switch down.

Thanks for the note re reset pins - not been like that the whole time, had been something I tried, but I never saw that warning. Good to know incase the dire warning is true

*Edit; also, amazing eagle-eyed spot!

Reply 68 of 71, by strange_loop

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rasz_pl wrote on 2023-09-13, 22:25:

voltage on motherboard power button pins?

Re-capped what seemed like the most likely culprits, not done the whole board - nil effect so far
0.13v at the power switch pins - there's some power going through the board. . .

Also, this is now testing with a brand new PSU - same results as previous

Reply 69 of 71, by rasz_pl

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strange_loop wrote on 2023-09-18, 15:55:
rasz_pl wrote on 2023-09-13, 22:25:

voltage on motherboard power button pins?

0.13v at the power switch pins

should be more like ~4V. Open the schematic and trace it back to the source. Its possible you damaged one of components on board while mounting expansion cards.

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Reply 71 of 71, by shevalier

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In this post, rasz_pl posted a schematic for a very similar board.
It has either custom silicone on it or something re-labeled from Winbond, with the name MSI-5, only with software control (page 41).
Very similar in structure to w83304d
The beauty of such controllers is that they work perfectly, unlike the discrete solutions born from the clouded minds of motherboard developers. The disadvantage is that they are difficult to troubleshooting because there is a lot of logic inside.

If the motherboard has MSI-5, then you need to check whether +5V sb is coming to it, whether the chargepump (+9V) is starting and whether the controller has turned on the +3.3Vdual source and +5Vdual

PS. Check out the Q74 and Q23 (NDS351AN-S) in the SOT-23 package. It doesn't look like it's suitable for the wattage and can easily burn out.

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