IBM R31 type 2656-rj8 LCD flickering showing lines

[fabianusv]

hello thinkpad folks,

need advices from you all folks.

my ibm thinkpad r31 2656-rj8 got problem on the lcd screen.
at start-up lcd is good, but after several minutes, the lcd screen is showing random lines (something like there is loosen connector inside the lcd) and it is very difficult to read the lcd.
the lcd can only be read from certain angle from the side of lcd. the lcd still emits light (i guess the lcd lamp is ok).

please help ...... what components / parts to replace?

this symptoms indicates there is broken parts probably a capacitor, because if i shutdown and let it cool down. then turn-on it again. the lcd is ok.
but if not waiting for cool down, then turn-on it again, the lcd is still difficult to read.

when the problem comes (lcd screen difficult to read), i tried to connect an external monitor to the vga 15-pin port and the external monitor shows perfect picture but the internal lcd still difficult to read.

any others also have the same symptons with this ibm r31.

what solution. thanks in advance.

video in mp4 format can be found here.... http://www.sendspace.com/file/2fsswk

others pictures can be found here.....







<a href='http://www.sendspace.com/file/nt79sc'>h ... /nt79sc</a>

[BillMorrow]

i don't think sendspace is a good host for pix..

from the description your problem sounds like the display is the cause and not the system board or gpu..

[SMA]

Welcome to the forum.

I cannot say that I have seen similar symptoms.
But I have seen an error in the dc/dc conversion circuitry. I have had that error on 3 different r31 boards lately.

Assuming that the screen flickering is caused by an unstable dc power then your problem might very well be the same.
It is a capacitor getting loose. Unfortunately, it is located on the bottom side of the mother board, but looking at
your pictures, it seems that you have the machine opened already.
I would recommend you to check it. Read my story here. There is a link to a picture in the fifth post.

[fabianusv]

i don't think sendspace is a good host for pix..

from the description your problem sounds like the display is the cause and not the system board or gpu..

thanks bill for the info.
unfortunately i don't have another lcd unit for testing.


most of the time i use sendspace, any other alternatives for hosting pix? which is easy for uploading and downloading pix?

[fabianusv]

Welcome to the forum.

I cannot say that I have seen similar symptoms.
But I have seen an error in the dc/dc conversion circuitry. I have had that error on 3 different r31 boards lately.

Assuming that the screen flickering is caused by an unstable dc power then your problem might very well be the same.
It is a capacitor getting loose. Unfortunately, it is located on the bottom side of the mother board, but looking at
your pictures, it seems that you have the machine opened already.
I would recommend you to check it. Read my story here. There is a link to a picture in the fifth post.

hello sma,

thanks for the post. i am really new in this forum, and i found the response from members are instant!!!

have looked into your story and also your pix.
this make me inpatient to dismantle further to the bottom board (which is the mainboard) to find the capacitor you pointed to.
but i don't have skill to do soldering like you did which is pretty neat and perfect. beside that difficult for me to find such as SMD cap over here. unless i take it from other damage boards.
others said, moving caps from board to other board is not recommended since this cap suffer from too much heat when moving (what is your opinion and experience regarding smd cap?).

another additional info regarding my case is.....
this flickering symptom occurs just recently after i adding up one memory module. my memory was 256 and now 512. after adding up memory to 512, this symptom comes.
could this be related one to another?

from what you explained about unstable dc supply, i try to assume that this could be caused by additional memory drawing more electricity current and since the caps you mentioned is already old in my r31, then make it unable to do its job.
i take out the additional memory and try again. but this does not help. the lcd still flickering after couple of minutes.

another find out when i try to clean the fan cooling unit, i found that heat sink module having dry contact to the cpu and also another chip next to the cpu (under an aluminium sheet). could this be the caused? do i need to add heat-transfer-paste since there is no problem with the cpu?

is the chip next to cpu is the r31 gpu?

[SMA]

In your case, the SMD capacitor I am talking about cannot be completely gone. It will have to be there. Otherwise, your r31 would not start at all.
So you will have the choice of trying to re-use the old one. It might still be good.

About finding replacement components I would say, that the correct thing to do is to use new parts. Second best - reuse components from
another piece of electronics. Last resort - reuse the old, possibly failing component.

Even if you cannot do the soldering, I will still recommend you to take a look. Just to know might help you.
And - do not get disappointed if this is not it - I am guessing here. But, as already mentioned, this has been the case for me 3 times in a row.
On the latest one, the capacitor was still sitting there, but it fell of when I gave it a very light touched.

R31's does not have any dedicated VGA memory. They are using a part of memory on the memory module(s) as VGA memory. Therefore, changing the amount of
ram can be what has triggered the screen flickering.
In BIOS Setup, there is a parameter for changing the amount of ram to set aside for VGA usage.
You could try lowering this value, just to see if it makes any difference.
It is possible that bios will adjust this value automatically when it detects that more memory has been added to the system. The bios default value may also
vary with the amount of ram. Therefore you may have reverted to 256 MB ram without having this parameter set back.

I have seen it my selves, and there are also others on the forum, who has reported about finding a CPU with no thermal paste in an r31.
These machines have been working for years, so thermal paste cannot really be that much needed. But sure, it will be a good idea to add some.

There is no dedicated GPU chip.
Here is what I found on the Lenovo support site.

Intel 830 MG chipset Integrated Direct AGP 3D Graphics dynamically allocates system main memory for video memory usage
up to 32MB based on application, demand, and available memory resource

[fabianusv]

In your case, the SMD capacitor I am talking about cannot be completely gone. It will have to be there. Otherwise, your r31 would not start at all.
So you will have the choice of trying to re-use the old one. It might still be good.

About finding replacement components I would say, that the correct thing to do is to use new parts. Second best - reuse components from
another piece of electronics. Last resort - reuse the old, possibly failing component.

Even if you cannot do the soldering, I will still recommend you to take a look. Just to know might help you.
And - do not get disappointed if this is not it - I am guessing here. But, as already mentioned, this has been the case for me 3 times in a row.
On the latest one, the capacitor was still sitting there, but it fell of when I gave it a very light touched.

R31's does not have any dedicated VGA memory. They are using a part of memory on the memory module(s) as VGA memory. Therefore, changing the amount of
ram can be what has triggered the screen flickering.
In BIOS Setup, there is a parameter for changing the amount of ram to set aside for VGA usage.
You could try lowering this value, just to see if it makes any difference.
It is possible that bios will adjust this value automatically when it detects that more memory has been added to the system. The bios default value may also
vary with the amount of ram. Therefore you may have reverted to 256 MB ram without having this parameter set back.

I have seen it my selves, and there are also others on the forum, who has reported about finding a CPU with no thermal paste in an r31.
These machines have been working for years, so thermal paste cannot really be that much needed. But sure, it will be a good idea to add some.

There is no dedicated GPU chip.
Here is what I found on the Lenovo support site.

Intel 830 MG chipset Integrated Direct AGP 3D Graphics dynamically allocates system main memory for video memory usage
up to 32MB based on application, demand, and available memory resource

hello sma,

your explanation completely very clear.

i have dismantle the unit until i can find the capacitor.

here is the picture.....


http://www.sendspace.com/file/zu3sxm

the capacitor still sitting there and the soldering connection is in excellent condition (see the picture).

regarding the additional memory, i have also tried to remove newly added memory and the result still the same. i even move the memory from one slot to another memory slot.
still no result.

still waiting for more ideas and opinion. while waiting i assume now the controller board behing the lcd having problem. but need more opinion before continuing with the "surgery"