701CS power supply question

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trgrhappy · #1 Post by **trgrhappy** » Fri Jan 11, 2008 8:35 pm

I have an old 701CS I'm trying to resurrect. About 3 years ago I bought one of the p133 mainboard upgrades, about a week after that my power supply took a dump on me and it hasn't worked since. I finally got around to tinkering with the machine again. I replaced the top board. I have a PS that I bought off eBay.
The specs for the original supply is 16V 4.5a, but the replacement I have is a 3.2a.Would the differance in amps keep it from going theu post? The power light lights up, but it doesn't go thru post. The display is blank with no signs of life. What are the chances I fried the main system board along with the PS and top board?
Any help is appreciated.
Thanks

ajkula66 · #2 Post by **ajkula66** » Fri Jan 11, 2008 9:22 pm

Welcome to the forum!

A weaker AC adapter wouldn't prevent the unit from posting.

Without seeing the machine one can only speculate, but there is a zillion ways to fry the board...

Good luck.

sb102 · #3 Post by **sb102** » Sat Jan 12, 2008 3:44 am

Hello trgrhappy,

I use a power supply that came with my 390X to power my 701C and 701CS. At 16 volts it has 3.36 amps (this is printed on the label). Both of the machines are running perfectly and nothing bad has happened to them. But I had the same problem during power-up on the 701C. Took me some time to figure out that the responsible part was the battery pack. When I took it out, the laptop powered up nicely and booted into Windows. After clensing the pins on the battery and the battery suply connector in my ThinkPad with 96% alcohol and a cotton swab the problem vannished (but be carefull if you want to clean it- avoid placing the swab on more than one pin - there is a risk of short-circuting the battery). Another idea is to check the wether the connectors of the LCD matrix are properly mounted on the systemboards and the upper system board connector is pluged in the lower systemboard slot.

I hope that I was able to help you with the problem,
sb102

CornFlakes · #4 Post by **CornFlakes** » Thu Jan 17, 2008 2:23 am

Thank you sb102

Tonight, after running on AC for a while, I shut down my 760cd. Short time later, it wouldn't boot, just two beeps and a black screen. The PS was quite hot. I removed the battery and it fired right up. Seems to be running okay without the battery which wouldn't hold a charge well anyway.

sb102 · #5 Post by **sb102** » Thu Jan 17, 2008 10:58 am

Thank you sb102

Tonight, after running on AC for a while, I shut down my 760cd. Short time later, it wouldn't boot, just two beeps and a black screen. The PS was quite hot. I removed the battery and it fired right up. Seems to be running okay without the battery which wouldn't hold a charge well anyway.

Don't mention it. Im glad that i could help you.

trgrhappy · #6 Post by **trgrhappy** » Mon Jan 21, 2008 11:28 pm

OK, I THINK i have this figured out, but am not sure if I can save the board or not. Thinking back on what happened, the PS died during POST. I'm thinking the BOIS is corrupt. is there any way for me to reflash the bios when the computer will not POST? or am I going to need a new board for it.
I have tried re-seating the LCD matrix cable with no response. The only battery I have is more than dead and will not take a charge at all.

Thoughts and suggestions?

Thanks

whizkid · #7 Post by **whizkid** » Tue Jan 22, 2008 11:15 am

You can't do it without extra hardware. You'd have to find an in-circuit programmer, or unsolder the BIOS chip and reprogram it. It would certainly be cheaper to buy another board than to pay someone to do it. But it's possible.

You also have to program the security chip with a checksum of the BIOS or the POST will fail on that, but you can buy those chips pre-programmed for most machines for around $15.

701CS power supply question

701CS power supply question

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