ThinkPad T500 stops working with replacable battery after 1

[masterxagent]

Hello,

I'm new on this forum and I have a problem with my thinkpad T500.
I replaced battery a week ago with non-original. Today my laptop stopped working and I'm despite in searching solution. I have electronic basics.
How problem manifests..

When I plug power cord (battery is out), laptop starts. Fan starts, DVD-RW starts to spin, temperature starts to rise up. LCD shows nothing, no light, no image.
Green LED indicators shows only that power is plugged in. When I press power button laptop reboots and all stays the same. It shuts down only when I plug out power cable.

What I have found out after I disassembly the laptop, I could smell burned wire on position where keyboard attaches to motherboard.
It could be that one inductor coil R56W is burned. It is not broken, does not luck burned and so on, it just smells bad (not sure is it from inductor). I'm not sure what is a problem.

Could someone help me to find and solve this problem, please.

Sorry for my bad english.

Kind regards,

Marko.

[emeraldgirl08]

Any luck getting your T500 started? If not what happens when you replace the non-original with the original? Do the symptoms persist?

[masterxagent]

Hello,

I did not find solution for this. When I put original battery nothing happens. Only when I plug in charger it starts, fan starts to spin, DVD RW also.
Cap lock and num lock blink ones. Only power cord indicator LED stays "On". There is no any sound, any beep, nothing. CPU starts to heat.
That is all.

I got it from my cousin and first day it did not even react on power cable. Than I did BIOS reset procedure (60 / 60 / 60), battery out and AC plug in while holding Power button.
There are many things I have tried. After that, it starts to respond, it powers on. (as it is now).

Is it possible that BIOS is corrupted?

I have voltmeter. What can I check and which readings should I get from power IC's etc. ?

Kind regards,

Marko.

[emeraldgirl08]

I am not sure what symptoms of a corrupted BIOS would be

Have you tried disconnecting the CMOS battery, reconnecting, and powering it up again?

[masterxagent]

Yes I did. That was a part of my investigation . I had one Acer laptop and I replaced BIOS chip and that fix a problem.

Problem with this thinkpad could be power regulator or what ever, burned CPU, or corrupted BIOS.
I do not have CPU to replace it and test it.

[ajkula66]

Your CPU is fine, otherwise the fan wouldn't spin.

BIOS corruption is unlikely as well, unless you've recently attempted an update and it failed.

A fuse blown on the board from the non-genuine battery comes to mind.

Remove all the RAM and power the laptop on. Does it beep?

[masterxagent]

Hello,

It does not beep when I take out memory. I would like to read/write BIOS chip with programmer, to check is it ok.
Do you have any other idea what could be wrong and what should I check first?

[ajkula66]

No one here will guide you through BIOS chip re-programming, that's against the forum rules.

With that said, the board that doesn't beep with RAM removed is as good as dead 99.9% of the time.

Good luck.

[masterxagent]

I had one Acer laptop which did not beep when RAM was removed. I replaced BIOS chip with new one I bought on eBay and laptop is working now.
It was BIOS failure. No sound, no beeps, no screen image, no led flashes.

This thinkpad did not even respond on AC power, now it does. What I did is only BIOS reset. I think that bios is corrupted.

[ajkula66]

Since you obviously have little regard for anyone else's experience apart from your own, all I can do is wish you good luck. Seriously.

[masterxagent]

I learned not to give up too easily, at the end I find solution for something. I had one laptop to service which was previously in five main service centers before it came to my hands.
At the end, I found solution and make it work.
If someone can give me a tip that will speed up a process. A tips helps in this situations, as more I try, closer I will be.

At the end, I will write down all what I did to make it work . Now I'm removing BIOS and security chip.
I measured voltage on mosfet's and it is constant 20V. After 4'th reboot voltage goes to 0 V.
Laptop sometimes reboots only once, sometimes 4-5 times and than shuts down. Sometimes fan starts to spin and stay spinning for 10-15 sec.
It is changing time to time, on every AC power plug in.

[ajkula66]

I learned not to give up too easily, at the end I find solution for something.

No one said that you should give up easily.

However, you most definitely are on the completely wrong track.

I don't know anything about ASUS, Acer or Toshiba, but have forgotten more about ThinkPads than most people will ever know.

A ThinkPad with a corrupt BIOS *will* beep. No ifs, and or buts.

Yours doesn't.

If you end up being lucky and end up fixing the problem that you're unaware of while troubleshooting healthy components, good for you. I just wouldn't bet on it.

[masterxagent]

Well.. I fixed motherboards which other service companies would throw away. Also they said "it's impossible to fix".

Well let's get back to T500. I removed BIOS and EEPROM security chip. This did not change anything. I was hoping that something will change, but nothing.
I measured voltage on inductors W56 and I get value 95 V DC. I guess it is from signal generator.