VOGONS


First post, by Miphee

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I got this computer with the TCM-200A socket 7 motherboard that is incompatible with the standard socket 7 Pentium CPUs.
The seller didn't know this and put a standard socket 7 CPU in it so now it smells worse than my wife's cooking: burnt smell everywhere. It looks flawless though. I need the Cyrix MediaGX CPU pinout to compare it with the Pentium pinout and start looking for the possible culprit.
I don't have a MediaGX or compatible CPU right now to test it but it's on the way. The seller claims that nothing was burning/smoking when he tested it, but let's just say that I don't really trust him.
I bought it anyway as a toy to practice my fault detecting and SMD soldering skills.
There could be nothing wrong with it but the smell is a dead giveaway... or it was rescued from a burning house. The smell is so strong that I can smell it across the room.
I gave it to the wife and she says the smell is the strongest in the CPU socket area.
Maybe you can spot something I couldn't but the pinout would be important to start.
Thanks.
(Or maybe it's the little PSU, impossible to tell. I'll test that tomorrow.)

Reply 1 of 9, by Miphee

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More pictures.

Reply 2 of 9, by red-ray

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See the attached

Reply 3 of 9, by Miphee

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Thank you so much!

Reply 4 of 9, by cyclone3d

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Could be that it just fried the CPU that was installed in it.. and maybe/probably in the process made some of the cpu socket pins so hot that it melted the socket plastic a bit.

Yamaha modified setupds and drivers
Yamaha XG repository
YMF7x4 Guide
Aopen AW744L II SB-LINK

Reply 5 of 9, by Miphee

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Could be. I checked it thoroughly under magnifying glass but found no burns or discolorations. It looks fine so moving onto the PSU.
I already see discolorations, burns on the negative supply transformer and signs of soldering/solder overheating. I'm 90% sure that the source of the smell is the transformer. Needs load testing and temp check on the parts under full load. It's a very small case with no ventillation, the PSU has no fan and heat transfer between the power switch transistor and the small heatsink is poor. A generally flawed design bound to fail.

https://www.parkytowers.me.uk/thin/esesix/wlgx01/

Reply 6 of 9, by Miphee

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Is the green wire the PS_ON? It is called CTL on the power supply's PCB.

Reply 7 of 9, by Miphee

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"ONCTL Output
On/Off Control for the RTC’s Advanced Power Control (APC) –
This signal indicates to the main power supply to turn on power.
ONCTL is an open-drain output signal that is powered by VCCH."

Is it the same as the green wire PS_ON output on ATX power supplies?

Reply 9 of 9, by Miphee

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Tiido wrote:

Grounding the signal will turn the power supply on so on that regard it is functioning like ATX PSUs.

Thank you, worked like a charm.
Here is the BIOS dump if anyone needs it.