DFI P5VB3+ dead with bad caps and more...

[canal]

Hi!

I'm here because my old (but usefull was) motherboard DFI P5VB3+ stop functionning ! Days before, things goes wrong and I've done one more backup of my disk. That was a good idea !!!!

By things goes wrong I mean : sometimes Windows blue screen errors - seems to be memory errors ? Full fill colored display - seems to be videocard errors ? Or perhaps PSU errors ? In fact, I didn't know what exactly goes wrong.

Finally, everything died (surely PSU + Mobo + Hard Drive + perhaps CPU?). 5 caps near CPU seems to go wrong (not flat/doomed ones). I also tried with a brand new PSU with no success.

2-3 caps near that area seems to be okay... Then, finally, I unsolder the doomed ones... but after that I noticed a transistor just near has burnt (yes burnt !)...

So my question is simple : do you think it's worth changing all that ? Of course, 5 capacitors + 1 transistor (is CEB6030L) must be cheap and I've already done all the hard job but... have I chances to get my mobo back again ?

Alex.

[Dan81]

Re: DFI P5VB3+ dead with bad caps and more...

Well,at this point you could try and see. If it doesn't work,you could replace the motherboard with another MVP3 based motherboard. (DFI P5VB3+ uses the MVP3 chipset FYI)

[stj]

Re: DFI P5VB3+ dead with bad caps and more...

check the psu caps - just incase it caused all this to begin with.
it must be old - mvp3 afaik is used with cyrix 686 and amd k6-2 cpu's

[canal]

Re: DFI P5VB3+ dead with bad caps and more...

[was bad placed]

[canal]

Re: DFI P5VB3+ dead with bad caps and more...

[Right place]

@stj : OK. I've unscrewed the PSU and happilly found no bad caps inside. Nothing burnt also... All seems okay (except for excess of dusts I've cleaned !). I've test +5volt and +12volt then get +5 and +12 (but PSU alone - nothing plugged) ! Can't test further as the AT (not ATX) plug isn't easy for that !

Yes, old: 16 years old ! But use it since that time everyday until 2 month ago... It seems the mobo could accept K6-III ... (Super 7 socket) but didn't exist at that time and so was not mentioned in the documentation...

@Dan81 : Everything is unsoldered now... And yes, I've already have a look at others mobo ... and found that after that P5BV3+ was a K6BV3+ ... Why not buying the best I couldn't afford in 1999

Thanks for your answers ... I'll give it a try ... and tell you what happened ... Hoping all that works ...

Alex.

[stj]

Re: DFI P5VB3+ dead with bad caps and more...

those old AT psu's are well built, i'm not surprised it's still good.

i have one i use for testing 5v and 12v stuff, i recapped it a couple of months back even though it didnt need it simply because i had it in bits to add an external ajuster pot.

they really dont build stuff that well anymore!

[Dan81]

Re: DFI P5VB3+ dead with bad caps and more...

those old AT psu's are well built, i'm not surprised it's still good.

i have one i use for testing 5v and 12v stuff, i recapped it a couple of months back even though it didnt need it simply because i had it in bits to add an external ajuster pot.

they really dont build stuff that well anymore!

Back then even Capxon was good .

I have a PCB from a old Seventeam PSU (of which the cover is now used on my Delux 400W PSU) and it had CapXon caps,but it worked like a charm.

[stj]

Re: DFI P5VB3+ dead with bad caps and more...

i have a 7team 350w tower psu from a 386 server that i still use to power a tower with a k6-2 and 7 harddrives in it - the airflow from the psu is hardly warm and it has been running almost 24/7 since it was new!!!!

[Majestyk]

Re: DFI P5VB3+ dead with bad caps and more...

You can even run an AMD K6III+ (up to 550 MHz and more) on the DFI P5BV3+ after a BIOS update and still use it for office applications today. There was a ATA66 version of this board also.

I hope you can get it fixed again.

[stj]

Re: DFI P5VB3+ dead with bad caps and more...

canal
have you got a beeper or speaker hooked up to the board to hear any beep-codes?
and did you try a different cpu?

[canal]

Re: DFI P5VB3+ dead with bad caps and more...

Ho ! Sorry, for long answer !

I've recapped the mother-board (for a total of 5 caps 1000uF) and changed the burnt/died CET CEB6030L by a 75N08 (MOSFET replacement as someone told me). Was TO-263 and get TO-220 instead... so a bit harder to solder but I've done it !

In the meanwhile, I discovered the CPU (a K6-2 366MHz) has died also: burnt in its center. So, I'm stuck for the moment ... Of course, nothing works.

@Majestyk: By ATA66 I suppose you speak of DFI K6BV3+ mother-board ? But can't find this board on eBay for now. / Also, I've read P5BV3+ is limited -but not documented- for K6-III (or K6-2+ I expected) to 400MHz ... because of 3.3v AT (and perhaps ATX) PSU issue. The issue is not for K6-2 ... so a K6-2 533MHz or 550MHz AFX for example would be great. K6-III at same MHz would be a little faster of course.

It seems K6 CPU for Mobile or Embedded with 1.6v or 1.8v will not fit on this board... which start with 2.0v unless overclocked ?

@stj: Yes, a speaker was/is plugged. Sadly, no bip. In fact, it's seems normal as the CPU has died also. I'll try with a new CPU and get back soon with news !

Alex.

[lti]

Re: DFI P5VB3+ dead with bad caps and more...

Check the CPU core voltage before putting in a new CPU. There might be other components that failed. The voltage across the caps you replaced should be either 5V (VRM input) or 2.2V (VRM output - CPU core voltage).

[canal]

Re: DFI P5VB3+ dead with bad caps and more...

@iti: okay ... but where to test these voltages ?

Do you mean testing board plugged (PSU voltage on) without CPU and test Vcc2 and Vcc3 socket pins directly on the board ..??

There is no indication of voltage test points marked anywhere on the board... and I've found no reparation manual about this DFI P5BV3+ ...

In case other(s) component(s) should be dead also (despite they look good) ... Which one can be ? Another CEB CET6030L (there is two - I changed only one) ? Another caps just near ? Any SMD -CMS in French!- chip (hard job!) ?

Alex.

[stj]

Re: DFI P5VB3+ dead with bad caps and more...

test-points are the capacitor wires on the bottom of the board.

[lti]

Re: DFI P5VB3+ dead with bad caps and more...

Yes, measure voltage on the cap leads. I don't think there is anything else you can do. There is a small chance that there might need to be a load on the regulator output, but I haven't seen that yet.

The second MOSFET, the controller IC (SMD chip near the two FETs, based on the tiny picture of that board I saw), or some related passive component (resistors, inductors, or caps) could have failed at the same time. That doesn't happen very often, but it's a good idea to make sure you aren't going to instantly kill the replacement CPU.

[canal]

Re: DFI P5VB3+ dead with bad caps and more...

The best picture I found is this one : http://www.amoretro.de/wp-content/up...otherboard.jpg
Everything is located on the lower right end of this picture between the BIOS, Socket, DIP switch and border of the board. But you already found that.
I've changed the 4 same caps and only one CET CEB6030L -the right one- (left one seems good - no conduction between its 3 pins), and last: the bigger caps -but all seems on the same size on this picture-. It's the one just upper the right yellow reel. 2 others caps left -unchanged- are, I think, 470uF ...

And now, I will do the tests you asked... get back soon.

[canal]

Re: DFI P5VB3+ dead with bad caps and more...

"test-points are the capacitor wires on the bottom of the board." !!!

OK... As each "-" go to ground and all 4 caps are put together "-" to "-" and "+" to "+" ... there's only on solution :-D So I've test between one "+" of one new caps I've changed and between ground and got ......... 2,22volt ... seems to be stable ! It's exactly what I expected to have as the board is configured by DIP-switch to deliver 2,2 volt !!!

Good news isn't it !?

Is there a way or need to test for 3.3volt (I/O) -3.6v max- as it's another crucial voltage for the CPU ... ? But, certainly 3.3volt is directly delivered by the new ATX power I use and it's a brand new one.

Alex.

[stj]

Re: DFI P5VB3+ dead with bad caps and more...

3.3v should be on a cap near the pci slots.
there is also a voltage regulator next to the ram slots, but i dont know what voltage it should be.

btw, if you play wih the switches/jumpers you canoften get unlisted voltages & frequency's for unlisted cpu's on old motherboards.

[canal]

Re: DFI P5VB3+ dead with bad caps and more...

Here's some news ...

... as I've just received a cheap new AMD K6-2 (bought from eBay) by post few hours ago. It's sold as NEW (neved used before) for only $9.95 + S&H ...

@stj: I've located the cap for 3.3v between AGP and one PCI slot ... check and found 3.3v okay !

Then, I've changed from 2.2v to 2.0v as my new K6-2 ask for that by DIP-switch and check again the caps I changed ... and now found 2.0v (instead of 2.2v)... seems good !

As Iti said, I think there's no much I can do before testing for real ...

In any case, the new K6-2 I bought is very cheap and no matter if it doesn't work ...

So, let's go ...

... test new ATX PSU + Mobo + RAM + CPU + Fan + VideoCard (SiS6326) - only that. No much.

[canal]

Re: DFI P5VB3+ dead with bad caps and more...

So, ... it POST !!!!!! (yes really - good news !)

But I have to immediately stop it because the CPU fan was asleep / not running. Don't know if it is normal or not. So, by security stop everything.

Then, I tested the CPU fan separately with 12v on red & black (nothing on yellow).

The fan start then stop ... There was little dust I remove. Then start then stop again ... seems to malfunction and after 4-5 minutes of tests: smoke !

Now, the CPU fan is dead. So no news before I get a new one !

But by now, I would like to thanks everybody for your help and advices ... It's seems it's pretty possible to repair such a mother-board (and perhaps others cards and PSU ...).
For the moment, don't know if it is stable ... will see !

Alex....