New BP6 and issues

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drasnor
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New BP6 and issues

Post by drasnor »

Through some strange and fortunate circumstances I now have a free BP6. Well, not completely free. My sister's fiancee's computer developed instability problems and we traded him our family's spare Dell P4 1.4GHz (Williamette = ewwww) system for his. Imagine my surprise when I opened it up to find an Abit BP6! Some things just shouldn't be owned by computer newbies.

Naturally, it is suffering from the full gambit of BP6 problems in addition to the traditional neglected computer stuff: two capacitors have ruptured but fortunately haven't spilled electrolyte all over the motherboard. It's a rev1.0 so it's going to need some work. What differences exist between the 1.0, 1.1, and 1.2 revisions?

I've taken davd_bob's advice and fired off an e-mail to Jackson, so maybe they'll send me some replacement capacitors. I also looked over the Q6 regulator fix, and I have some questions with regard to that.

What exactly is Q6 responsible for? Does it produce the processor core voltage, or is it supplying power for something else on the motherboard?

I looked up the datasheets for the LM317 on the National Semiconductor webpage, and found that they had several recommended alternatives. Has anyone looked at the National LMS8117A as a possible replacement? The TO-252 version of it uses the same package as the original Q6 on the BP6, while offering much lower dropout voltage (1A at 1.2 deltaV). National will send you up to 5 free samples a week, so availability isn't a problem.

-drasnor
drasnor
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Post by drasnor »

I got an e-mail from Jackson this morning: capacitors are on the way!

I took another look at the LMS8117A datasheet and it looks like it requires a bypass capacitor between the output and ground to stabilize the output voltage. Most regulators require a similar capacitor to function, so it's likely that one of the surface mount capacitors in the Q6 area serves this function. However, the datasheet recommends a 22uF solid tantalum with 10uF as a minimum, while the LM317 recommends a .1uF tantaluim with a maximum value of 10uF on the diminishing returns curve. I doubt Abit put a 22uF capacitor there, so I'll need to figure out which capacitor belongs to Q6 with my multimeter sometime.

-drasnor
Last edited by drasnor on Wed Apr 07, 2004 12:12 pm, edited 1 time in total.
davd_bob
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Post by davd_bob »

When my caps arrived there were 15 of the 1000uf and 15 of the 1500uf. That means there were some spares.

I was going to make a thread or an article on HOW TO but after the job i did i kind of lost confidence. I will still probabay do it. I was ashamed of the job i did on my own board...but it works now.

Some of the caps on my revisionn 1.0 were jackson and some were another manufacture. I only replaced the 8 caps that look like 4-pack. 7 of those were bulging/leaking. anyway, my cpus were working ok and temps/voltages ok. the chipset howerver was 20 degrees hotter anytime there was a load. it hit 80 at least once. after the cap change it is now 2-5 degrees hotter then then the cpus. thats running at 66fsb.

pm or email me when you do the soldering work.
There are *almost* no bad BP6s. There are mostly bad caps.

No BP6s remaining
Athlon 2800
Sempron 2000
ViaCPU laptop with Vista.(Works great after bumping ram to 2Gig)
P-III 850@100
drasnor
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Post by drasnor »

How bizarre. Northbridge should be cooler than the CPU's. Have you put any thermal grease under your greenie? I'm going to replace mine with a Vantec copper Iceberq because I have some that I got on sale a while back. Active cooling + copper heatsinks generally solve most thermal issues ;). To me, 70C is flirting with danger, 80C is just unacceptable.

On a side note, my other 440BX boards have fairly cool chipsets. That includes my Asus P2B-DS, another dual processor BX board. It's running dual 1100/100 coppermines, but it's going to be running dual 1.4GHz Tualatins as soon as I get a pair of those from Newegg refurbs. I don't have the temps on its Northbridge, but I can touch it with my hand and it only feels a little warm.

I'm fairly handy with my soldering iron, so mine should come out nice and pretty. I'll try to take some photos to go with. The capacitors that failed on my board are also the ones in the quad packs, though I'm planning on replacing all the electrolytics. I haven't tried booting it since I got it, but I bet the instability problem stems from those.

-drasnor
davd_bob
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Post by davd_bob »

im scared to repalce any more caps. if i change the rest of the jacksons it may correct the chipset temps. voltages on MBM show ok now...but they did before the surgery so that may not mean anything. Yes on the greese. also put hsf for a video card on the chipset so it gets active cooling now.
I tried to remove solder with 15watt then a 25watt iron and a solder sucker(SS)..bulb also tried the spring loaded tube type also tried a radio shack 45 watt SS. I recomend atleast 30-50watt for removing solder from the holes that have a large ground on the bottom side. the other holes cleaned pretty well with all the SS combos.
There are *almost* no bad BP6s. There are mostly bad caps.

No BP6s remaining
Athlon 2800
Sempron 2000
ViaCPU laptop with Vista.(Works great after bumping ram to 2Gig)
P-III 850@100
drasnor
Posts: 7
Joined: Sun Apr 04, 2004 11:05 pm
Location: Coffee Station, TX
Contact:

Post by drasnor »

I've got a 50W temperature-controlled Weller soldering station, and I find that 550 F works well on most electronic circuits. I use the spring-loaded RadioShack solder sucker for my suckin' needs. I find that I don't need to get ALL the solder off when I'm desoldering components I'm going to replace. I just need to get enough solder out of the way of the hole so that the replacement component can fit through, then re-use the existing solder with maybe a dab from my spool to secure it down.

I understand how you might feel apprehensive about doing board work. I don't feel so bad, since mine's already broken and I got it for free ;). Just make sure you solder the capacitors in the right orientation. If you install it backwards, the capacitor will explode (ask me how I know ;) ).

-drasnor
davd_bob
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Post by davd_bob »

haha
i know how you know...

I have done solder work before but iwas still dissapointed in my work on those 8 caps.
There are *almost* no bad BP6s. There are mostly bad caps.

No BP6s remaining
Athlon 2800
Sempron 2000
ViaCPU laptop with Vista.(Works great after bumping ram to 2Gig)
P-III 850@100
drasnor
Posts: 7
Joined: Sun Apr 04, 2004 11:05 pm
Location: Coffee Station, TX
Contact:

Post by drasnor »

Well, I was home this weekend and looked at the original Q6 part on my BP6 and made a troubling discovery. They are Niko L1084D 5A low-dropout regulators, which should be sufficient for this application, meaning either these Niko regulators are crap or this isn't the problem. Also, these regulators are rated for 5A, which is ~1.5 A higher than the maximum rated current for the LM317 (recommended for use in the Q6 mod) and 4A higher than the regulator I was previously considering. Now I'm not saying that everyone who has done the Q6 mod is putting their board and processor at risk, but it's something you should be aware of.

Also, as I suspected there are two L1084D's on the BP6, one in the Q6 position and one at Q11, south of Q6. This makes sense, since the BP6 offers independent voltage control for each processor and if these regulators are responsible for processor voltage, there should be two of them. The National Semiconductor direct replacement for the L1084D is the LM1084, but they also offer a pin-compatible model with fast response to current changes, the LMS1585A. I sampled a couple of these in the TO-263 package, so they should be here in a week or so. The TO-263 is a little bit larger, but I think it'll fit.

-drasnor
davd_bob
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Post by davd_bob »

Try the caps first then test the board.
Keep evberyone up on the results.
There are *almost* no bad BP6s. There are mostly bad caps.

No BP6s remaining
Athlon 2800
Sempron 2000
ViaCPU laptop with Vista.(Works great after bumping ram to 2Gig)
P-III 850@100
drasnor
Posts: 7
Joined: Sun Apr 04, 2004 11:05 pm
Location: Coffee Station, TX
Contact:

Post by drasnor »

Yeah, capacitors haven't come yet. I'll let you know ;).

I just re-read the original VTT Q6 mod article, and it mentions that the crap VRM's are manufactured by Unisem, so the Niko models should be ok. Something to play with after I get the caps installed, I suppose.

-drasnor
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