VOGONS


First post, by behshad

User metadata
Rank Newbie
Rank
Newbie

Hey there,

my first time posting here! 😄 So, I've been hearing a lot of good stuff about Asus P3B motherboards, but I'm not having the best of luck with couple of mines. I had one which was plugged in (but switched off) and it started smelling like it was burning caps and then has refused to turn on afterward (PSU's fine).

Now, I've got this P3B-f (attached pic) that's rather temperamental,. It only powers up now and then. When I hit the power switch, the green light on the motherboard comes on, and that's it. But I have figured out that if I connect hard drive(s) and plug and unplug the molex/ATA cables a few times, the motherboard eventually starts up just fine. Turn it off, and I gotta do the whole molex thing again to get it going.

Unlike my first one, this motherboard's capacitors seem to look okay, at least to my eye. no bulging or leakage. i have tried different PSUs, graphic cards and CPU/RAMs are fine. although very difficult to push in the memory sticks. i even tried a new CMOS battery in it

I am into socket 7 and older models, but I really want 1-2 P2/3 Windows 98-era PCs for my collection. Any ideas on what might be up with this motherboard or how I can figure it out?

Thanks a bunch! 😅🙌

Reply 2 of 7, by dominusprog

User metadata
Rank Oldbie
Rank
Oldbie

Since these caps probably didn't connect to any power source for a long time, power cycling the board might bring them back to life. Also check for solder joints.

Duke_2600.png
A-Trend ATC-1020 V1.1 ❇ Cyrix 6x86 150+ @ 120MHz ❇ 32MiB EDO RAM (8MiBx4) ❇ A-Trend S3 Trio64V2 2MiB
Aztech Pro16 II-3D PnP ❇ 8.4GiB Quantum Fireball ❇ Win95 OSR2 Plus!

Reply 3 of 7, by behshad

User metadata
Rank Newbie
Rank
Newbie
rasz_pl wrote on 2023-08-27, 10:16:

replugging ATA cables bends the board and might reconnect cracked joint temporarily

I mostly unplugged/plugged the cables from the peripheral end though and not the board itself so the board shouldn't flex during this.

Reply 4 of 7, by behshad

User metadata
Rank Newbie
Rank
Newbie
dominusprog wrote on 2023-08-27, 11:49:

Since these caps probably didn't connect to any power source for a long time, power cycling the board might bring them back to life. Also check for solder joints.

I could be very wrong here but I can't help to think the power drawn by the peripherals might got something to do with this. it just feels as soon as the hard drive starts spinning up it brings the board to life. just a guess though.

Reply 5 of 7, by behshad

User metadata
Rank Newbie
Rank
Newbie

is there any way that I can test the capacitors i.e. using a multi-metre? with these types of intermittent issues wouldn't you always suspect the capacitors and go ahead and replace them?!

Reply 6 of 7, by CoffeeOne

User metadata
Rank Oldbie
Rank
Oldbie

For searching errors, I would try with a minimized system.
So I would remove the harddisk also keep only a single DIMM. Of course the graphics card must stay in. The post card is nice to have, too.
And then check if it powers up ALWAYS.

Reply 7 of 7, by behshad

User metadata
Rank Newbie
Rank
Newbie

thanks for all the input. it looks like that cache on the Pentium 3 CPU board could have been the culprit. I had to pay attention to my pc analyzer card, error 3E is cache controller error and as far as i know the cache is on the CPU card on these socket 1 CPU's. I tried a Pentium 2 which I had and now motherboard turns on all the time. i did put the PIII into another computer and it works there so i am a bit puzzled. glad that i now have a working P2/3 P3B system. planning to build this as an out of case bench-top naked sort of pc