Toshiba Satellite - Locks up when plugged in

[branko]

Question

hey guys,,

i finally got around to replacing the NEC TOKIN 0128 with 4 KEMET T520 SMT polymer caps(2.5V 330uF).

After finishing the job, i used a digital volt meter to check for continuity between the + and - sides(short circuit test) and noticed that the digital volt meter beeps for about 1 second and then stops. Is this normal or does it indicate that i did a crappy job soldering and caused some sort of short circuit?

Is there any good test i could do prior to assembling the laptop, that would ensure that i dont fry the processor/motherboard?

i could post a video if necessary....

any suggestions would be appreciated

[Notsosure]

Re: Question

After finishing the job, i used a digital volt meter to check for continuity between the + and - sides(short circuit test) and noticed that the digital volt meter beeps for about 1 second and then stops. Is this normal or does it indicate that i did a crappy job soldering and caused some sort of short circuit?

I hope you have chosen the correct range of resistance to check continuity. In my motherboard (A200) the resistance between the positive and negative pads on the motherboard reads around 5Ω. Therefore, choose the lowest range that covers this resistance. Also make sure that when you touch the two leads of the multimeter it shows almost zero resistance. I hope you have not melted the plastic cover of the caps while soldering?

Check and report back for further advice. Posting a photo of your work might also be helpful.

PS: Are you checking + and - sides of the pads or terminals of the cap?

[Notsosure]

Re: Question

Is there any good test i could do prior to assembling the laptop

Doing the following is advisable:

1. Check the continuity between the metal terminals of the caps and the pads to which they are attached, which should read almost 0Ω (Exact 0Ω, if you have adjusted zero of the multimeter properly). This will ensure that all the cap terminals have been soldered properly.

2. Check the continuity between the positive and negative pads, which should read around 5Ω or whatever your motherboard shows when nothing is connected between them. This will ensure that your soldering has not shorted the two pads.

3. Visually check that plastic covering of the caps is free of solder and/or it has not been damaged during soldering in any other way.

[Notsosure]

Re: Question

After finishing the job, i used a digital volt meter to check for continuity

I hope you understand at least this much that you need to use a multimeter in the appropriate range of resistance to check continuity and that is what you did? I am presuming all along that you mistakenly called it "volt meter"? Obviously there is no voltage to check when the laptop is not powered on.

[branko]

Re: Question

I hope you understand at least this much that you need to use a multimeter in the appropriate range of resistance to check continuity and that is what you did? I am presuming all along that you mistakenly called it "volt meter"? Obviously there is no voltage to check when the laptop is not powered on.

Semantics... i call them DVM's (digital volt meters) you call them Multimeters. From now on i will use the term Multimeter. sorry my mistake

[branko]

Re: Question

Doing the following is advisable:

1. Check the continuity between the metal terminals of the caps and the pads to which they are attached, which should read almost 0Ω (Exact 0Ω, if you have adjusted zero of the multimeter properly). This will ensure that all the cap terminals have been soldered properly.

2. Check the continuity between the positive and negative pads, which should read around 5Ω or whatever your motherboard shows when nothing is connected between them. This will ensure that your soldering has not shorted the two pads.

3. Visually check that plastic covering of the caps is free of solder and/or it has not been damaged during soldering in any other way.

1) i have checked the connections between the cap terminals and motherboard pads, and have obtained a reading of 0 ohms between each cap terminal and the pad that it happens to be on. My multimeter has a continuity test, which emits an audible beep when a circuit has continuity, i have used this setting and it beeps when probing between MBO pads and the cap terminals on that particular pad.


2) i used the lowest scale available on my multimeter which is the 200 OHM scale. Unfortunately , i did not take any ohm readings after removing the NEC TOKEN (when there were no caps on the motherboard), so i do not know the OHM values between the pads.
SHould i remove the 4 caps in order to obtain this reading/ohm value?

3) will take a better look


4) QUESTION: when i take my multimeter and select the 200 OHM scale and probe between the + and - side of one set of caps i get a constant reading of 82ohms, the same applies for probing between the + / - pads on which the caps are soldered.

However, when i probe the other/opposite side, my multimeter shows about 120ohms for about one second and then i get a constant reading of "1" on the display of the multimeter . i believe that "1" indicates an open circuit or no continuity. when i use the audible beep continuity tester on each set of caps between the + and - pads i get and audible beep for about one second(maybe even less than a second long) and then the audible beep stops, is this ok ?or bad news?

any ideas?

[Notsosure]

Re: Question

1)any ideas?

The resistance between +/- of the caps, when they are not soldered (or soldered improperly), could be extremely high (may be kΩ, MΩ or even open) but once they are soldered properly they should show same resistance as between the open +/- pads. So where you are getting 1, you should select higher ranges and try. Sometimes oxide films, etc on metal surfaces also make it difficult to obtain good contact just by touching so a bit of scratching might be necessary. In any case if all the cap terminals have been soldered properly (as it appears) and there is no shorting between the +/- pads (check again) you should be good to go ahead. Try and let us know.

[Notsosure]

Re: Toshiba Satellite - Locks up when plugged in

branko,

To add further, the two metallic terminals of the cap are separated by a dielectric medium inside the cap. Therefore, in an open cap (i.e., a cap that has not been soldered), you are essentially measuring the inherent insulation resistance of the dielectric, which is often in MΩ. If the resistance is so high that it is beyond the capability of your multimeter then it may just show 1 (i.e., open).

I presume you are getting 80Ω in one set of +/- pads and 1 in the other set of +/- pads? It appears to me that your other set of pads has a resistance higher than 200Ω for reasons unknown to me (I am not an expert anyway). Just go to higher ranges and see if you get a stable resistance value. As long as you have not shorted the +/- pads I see no risk in powering up your laptop. Just go ahead and you will most likely be well rewarded for your efforts.

PS: In our experience, the resistance between the two positive pads as well as between the two negative pads is 0Ω. Don't you get this value?

[branko]

Re: Toshiba Satellite - Locks up when plugged in

I presume you are getting 80Ω in one set of +/- pads and 1 in the other set of +/- pads? It appears to me that your other set of pads has a resistance higher than 200Ω for reasons unknown to me (I am not an expert anyway). Just go to higher ranges and see if you get a stable resistance value. As long as you have not shorted the +/- pads I see no risk in powering up your laptop. Just go ahead and you will most likely be well rewarded for your efforts.

PS: In our experience, the resistance between the two positive pads as well as between the two negative pads is 0Ω. Don't you get this value?

> yep, i am getting 0 ohms when measuring between the two + pads as well as between the two - pads.

unfortunately, i do not repair electronics on a regular basis, so my multimeter skills are horrible.
once again you were right. i forgot to try measuring oHMs with the next higher up scale( on my multimeter its 2000ohms). when i measured resistance using the 2000 ohm scale, here's what happened:
the reading gradually increased from 500ohms to 1862 ohms, where it stopped after exactly 60 seconds. In other words, after probing the other set of caps for more than 60 seconds the reading on my multimeter was a constant 1862ohms. this is what confused me, i was expecting similar ohm values
between the two sets of caps, whereas i got 80 ohms with one set of caps and 1860 ohms with the other set, is this normal?

one more question:
in my last post, under 4) i mentioned the multimeter continuity test using the audible beep , is the short beep normal?


thanks for taking the time to help me out, and thanks for sharing your knowledge with all of us. am extremely grateful

[Notsosure]

Re: Toshiba Satellite - Locks up when plugged in

[QUOTE=branko;263663 whereas i got 80 ohms with one set of caps and 1860 ohms with the other set, is this normal?

one more question:
in my last post, under 4) i mentioned the multimeter continuity test using the audible beep , is the short beep normal?
:[/QUOTE]

Since both your negative and positive pads show continuity, getting 80Ω in one set of pads and 1860Ω in another is not normal. They both should show same resistance. However, there is a possibility that the pads have some flux left on them and hence show higher resistance than expected. Just don't bother about the exact values.

I would not bother much about short beep as well. My guess is it initially finds continuity and beeps but when it finds that the actual resistance is higher than the range you have selected it stops beeping.

Since you have not shorted the +/- pads and hopefully taken care of the cap polarity it is time you power it up.

[Notsosure]

Re: Toshiba Satellite - Locks up when plugged in

i got 80 ohms with one set of caps and 1860 ohms with the other set

I have been writing “set of pads” but you seem to be checking between “set of caps”. You have earlier mentioned that each cap terminal showed continuity (0Ω) with the respective pads to which they have been soldered. Therefore, you have to get the caps out of the picture. Simply check the resistance between the two sets of +/- pads. They will surely be accessible somewhere along their length. They will probably show 5Ω or higher, which is fine. You have to worry only if they show almost 0Ω.

I expect your next post to say your laptop is working now.

[branko]

Re: Toshiba Satellite - Locks up when plugged in

hello again ,

i just figured out why i was getting two different multimeter measurements for the different sets of pads. it turns out that when probing the pads, the multimeter readings are polarity sensitive. so when i used the red probe on the positive pad and black probe on the negative pad , for some reason the ohm reading shot up to 1800ohms, however when i used the red probe on the negative pad and black probe on the positive pad, i got a reading of about 80ohms, the same applies for both sets of pads.
does this mean all is well?

just to verify, i have a toshiba satellite A205 series , and from the research i have done, i believe that the outside pads are + whereas the inner two/middle pads are negative, is this correct?

According to the Kemet online documentation, their caps are marked with a horizontal black bar which indicates the + side of the cap. i soldered the positive cap sides to the two outer pads.

i plan on closely inspecting the board tonight, then hopefully give it a try by the end of the week

once again , thanks for your help

[Notsosure]

Re: Toshiba Satellite - Locks up when plugged in

does this mean all is well?

Yes, that is the best one can do and hope for the best. Ultimately the proof of the pudding is in the eating. Therefore, you will know the result when you power it up. One can never be 100% sure. In the unlikely event of laptop not working one will have to diagnose the problem again. Best of luck anyway.

[Notsosure]

Re: Toshiba Satellite - Locks up when plugged in

I have soldered 4 of RS Stock No. 737-2832 in my A200 (a bit shabby work) and it is working fine now. Please see my photobucket for photos: http://gs138.photobucket.com/groups/q251/S1BXDWUERU/

It might surprise people here to know that my A200 had started the restart problem again around 12 days ago. For few days it kept restarting almost once a day and within a week the problem became so severe that it kept restarting repeatedly within a couple of minutes of powering on the laptop. I would have possibly thrown my laptop in frustration if I had not posted the photos to help others, which provided me the clue and reminded me of the saying "God helps those who help others".

If you look at the top right side cap (in Photo No. 11 of my photobucket) you will notice that the plastic covering of the cap has melted while soldering. The top left side cap has also got affected but not that much. I just removed the top right side cap and the laptop has been working perfectly on 3 caps for about 5 days now. The 3 caps are enough to provide the required capacitance and ESR to last the lifetime of the laptop if everything goes well. I was just waiting to make sure that the problem is solved before letting others know.

[Philby]

Re: Toshiba Satellite - Locks up when plugged in

Morning All, my notebook, A200 PSAF6A-02C01N, has showed the same symptoms as above. I replaced the nec tokin oe128 with 4x tant cap 2.5v 470uf, RS p/n 737-2832, crossed my fingers and powered up. The message I have now is, Resource Conflict-PCI on Motherboard, Bus 08, Device :06, Function 01,02,03. Bottom line reads, <F1> to load defaults, <F2> to setup.
As I'm nowhere as computer literate as other members here keep it simple i.e fixable or a bin job.

[Notsosure]

Re: Toshiba Satellite - Locks up when plugged in

fixable or a bin job.

The error suggests that multiple devices are trying to use the same resources on your motherboard. You may have to enter BIOS and reset it back to its default settings. Pressing F1 probably does the same. Did you try it? This is not an uncomon problem and you may find lot of useful info on the Internet. In my view this error has nothing to do with the replaced caps. However, there is a possibility that you may not have conected back all the hardware components properly. Therefore, if resetting the BIOS does not work then you may have to do some research and look at threads such as: http://www.computing.net/answers/har...s00/70996.html

[Notsosure]

Re: Toshiba Satellite - Locks up when plugged in

...you may not have conected back all the hardware components properly...

...especially the Wi-Fi card shown at Step 9 here: http://www.irisvista.com/tech/laptop...assembly-2.htm
The three wires need to be connected back properly in the same order as they were earlier. Some people even suggest the card to be disconnected: http://www.techsupportforum.com/foru...rd-622931.html

[Philby]

Re: Toshiba Satellite - Locks up when plugged in

Tks notsosure for your reply. You seem to be a pioneer in this area. I went back and checked all devices were connected, nothing new found. Went into bios and return settings to default, no change. Tried to remove the CMOS battery but it is soldered so left it in its place. I've removed the hdd, optical drive and wireless card, no change but bios does show that these devices are removed. So my next step is?

[Notsosure]

Re: Toshiba Satellite - Locks up when plugged in

You seem to be a pioneer in this area.

Not really. Although I have a Ph.D. in engineering, it has hardly anything to do with computers or electronics. A little bit that I have learnt is through Internet in the past couple of years so I consider myself as just having a slight edge over a complete novice.

First and foremost, I am assuming that you have done a good job of capacitor replacement and checked things to make sure of it.

I suggest you put back everything except the wifi card and try, try booting from the dvd drive, and try any other simpler options you have read on the internet. People sometimes have found some strange solutions: http://pcshare.com/index.php?option=...id=75&Itemid=0
http://www.thinkpads.com/forum/viewt...hp?f=2&t=88095

If the simpler options have not worked then try the following after weighing the risks involved, if any (of course, if you wish, you can go straight away for this option as I am inclined to believe this might work): http://www.errorsupport.org/blog/res...therboard.html

If nothing works then you need to attract the attention of many more experts by starting a new thread on some relevant popular forums in the hope of finding someone who has come across a workable solution to this problem.

[Philby]

Re: Toshiba Satellite - Locks up when plugged in

Hi again, I have a diploma in marine engineering so I can fix boats but I think this notebook is about to sink.

Again, thanks for your support. Will follow up on links and see what happens.