I broke a pin on my mobile P4. Was it vital?

[WillDashwood]

Image of the pin in question

I bought a cheap mobile Pentium 4 off eBay and didn't check all the pins carefully enough (cpu's have shrunk a LOT since I was last tinkering) before inserting it. Yep, I bent a couple of pins and unfortunately I couldn't rescue one of them and it broke off in the process. The image above is the specific pin which broke. I just wondered if it would be safe to test the CPU anyway on the off chance it might still work. The pin is listed in the data sheet as VSS - Power/Other. Sounds dumb but are all pins used and important?

I was planning on breaking a pin or 2 to set the fsb to 200 and reduce voltage but of course I wasn't fortunate enough to break of those that I need to break :frown:

Thanks,
Will

 

[Soulkeeper]

apparently if the P4 is anything similar with it's pin naming as the tualatin then vss is ground
this could be trouble
i would recommend searching till you find out before running that chip again

btw i have a spare 1.8ghz p4m laying around that'll do a happy 2.6ghz

 

[Soulkeeper]

This might help
http://ftp://download.intel.com/design/Pentium4/datashts/24988703.pdf
datasheets list it as pin G6 that might help

 

[WillDashwood]

Thanks Soulkeeper. So perhaps not a best idea to just plug in and hope for the best! Well I'm buying loads of these things so I guess I'll just chalk this one down to experience and be more careful in future.

 

[Shimmishim]

Originally posted by: WillDashwood
Thanks Soulkeeper. So perhaps not a best idea to just plug in and hope for the best! Well I'm buying loads of these things so I guess I'll just chalk this one down to experience and be more careful in future.

i can't remember the webpage but there is someone that fixes broken pins off of cpu's for a litlte charge... ask around

 

[WillDashwood]

Well I only paid £20 for the cpu so I'm not too woried. I might try soldering something myself if I've nothing to loose. Just not sure what to solder in it's place!

 

[gwag]

may be you could stick some sort of pin in the socket that would contact the cpu when was stuck in?

 

[Soulkeeper]

check the datasheets they show exactely what the pin is made of and it's dimensions
maybe you can get some kinda really thin solder that melts and hardens fast to those kinda metals

 

[Jeff7181]

duct tape

 

[Mingon]

I have used an ide pin in a socket 370 board, socket 478 is smaller but will still work. . A pinor needle clipped to size should work.

 

[WillDashwood]

Interesting ideas. I think I would have to soldered to the cpu as this motherboard is my testing rig with cpu's going in and out all the time. I've no idea how I would manage to solder something so small. I would need a tiny soldering iron! Are there alternatives, such as some conductive sticky stuff!

 

[WillDashwood]

Sorry, missed this one...

Originally posted by: Jeff7181
duct tape

....ahem...eh?

 

[m3rb]

VSS is ground. There are a bazillion of them and they are all internally connected. I would be very surprised if missing just one would hurt anything. Try it and see.

 

[WillDashwood]

Well I think I might give it a try. Shame I don't have a cheap P4 motherboard to test it with. Can anyone see a worst case scenario involving the frying of my lovely Gigabyte 8I875?

 

[ceasar88]

Agree with m3rb. Use a meter to check if the broken pin is connected to other VSS internally. If so, your cpu will be just fine.

 

[Tiamat]

Originally posted by: WillDashwood
Well I think I might give it a try. Shame I don't have a cheap P4 motherboard to test it with. Can anyone see a worst case scenario involving the frying of my lovely Gigabyte 8I875?

Im no electrical engineer, but if you lack a Ground pin, there will be some voltage build up somewhere. Im not sure if lacking 1 ground out of several will be significant, but if it were myself, I wouldnt test it on a motherboard that costs more than the questioned processor.

 

[WillDashwood]

Well I did try it and in the process broke another pin off I'm sure I'll be getting a reputation around here!

But anyway, unbelievably it worked! It was another Vss pin I broke but the multi-meter showed it was linked to the pin right next to it so I figured I'd give it a try.

At 1.57 volts it wouldn't post past 1.7Ghz (it's a 1.6GHz cpu) which I'm guessing is how it's affected the cpu considering my 1.7Ghz cpu will do 3GHz at that same voltage. I'm just amazed it works! I lowered the voltage and got down to 1.3v but haven't tried lower yet. It wouldn't surprise me if I can go down to 1.0v which should keep the cpu nice and cool. I think this will be destined for use in a low powered server or PVR. 1.6GHz (133x12) is more than enough for this. Maybe even an old p4 motherboard that takes plain old SDRAM, making a very cheap setup. Tomorrow I'll put it through it's paces to see how low I can get the voltage before loosing stability, assuming it's stable in the first place (haven't booted into windows with it).

So there we have it, you can lob a couple of Vss pins off your P4 and all is not lost, except some serious overclocking fun. Anyone else care to try the same mods? I can see it becoming the latest craze for sure!

 

[Soulkeeper]

hahaha

 

[kyparrish]

yeah, as long as you had continuity between where the broken pin went and another grounded pin, you'd be fine

 

[WillDashwood]

Shame I can't compare before and after to see just how much it's hampered it's overclocking ability.

 

[kyparrish]

Originally posted by: WillDashwood
Shame I can't compare before and after to see just how much it's hampered it's overclocking ability.

it shouldn't hamper the overclocking ability,

as mentioned by another user, there are a gazillion ground points inside of the processor....all of those chips labeled VSS have continuity among each other, meaning in essence, it's one big interconnected component

having 2 missing ground pins should not hinder your OC'ing ability, as the chip should still produce the same amount of heat w/o those 2 pins, and should still be able to safely handle the same amount of voltage, and should still be able to handle the same temps w/ increased cooling