Archived from groups: comp.sys.laptops (
More info?)
Thanks again for the explanation Barry.
Barry Watzman <WatzmanNOSPAM@neo.rr.com> wrote:
>No, In this case I am suggesting that the inverter has a failure mode
>that causes it to fail a few seconds after starting almost every time.
>My point was that, in general, inverters do not get gradually "weaker"
>(read: dimmer backlight) over time. They work until they fail. But
>some failure modes are intermittent or are involved with "starting" (in
>particular because this type of lamp takes a higher voltage to "start"
>than to continue running). In this case, I think that's the failure mode.
>
>But the problem could be in the lamps themselves, although I think that
>is less likely.
>
>
>
>Don wrote:
>> So are you suggesting it is not the inverter that cause the problem??
>>
>> Barry Watzman <WatzmanNOSPAM@neo.rr.com> wrote:
>>
>>
>>>Inverters are solid state devices and usually do not deteriorate until
>>>or unless they fail completely.
>>>
>>>
>>>Quaoar wrote:
>>>
>>>
>>>>Don wrote:
>>>>
>>>>
>>>>>I can actually see the complete display every time I point a a bright
>>>>>led flash light against the screen. I guess it is not the problem with
>>>>>the LCD panel then ( which is good news for me as the panel is much
>>>>>more expansive ). I can find a used inverter on ebay for less than $10
>>>>>so I will give it a try then. When you say the inverter can give out
>>>>>over 1000 volts how should I replace the inverter? Is unplugging the
>>>>>AC power and remove the battery good enough then??
>>>>>
>>>>>Btw, thanks for the quick response.
>>>>>
>>>>>
>>>>>Barry Watzman <WatzmanNOSPAM@neo.rr.com> wrote:
>>>>>
>>>>>
>>>>>
>>>>>>It's probably the inverter, but if not the inverter, then most likely
>>>>>>the lamp(s). Although these are inside the LCD panel itself, they
>>>>>>can usually be replaced without replacing the whole panel, and at a
>>>>>>resonable cost (the lamps themselves are usually $10 to $30 each,
>>>>>>some panels use two of them, others only one). Replacement ranges
>>>>>
>>>>>>from very easy to very difficult and in a few cases impossible.
>>>>>
>>>>>>(Digikey has a reasonable selection of generic replacment lamps if
>>>>>>you know the diameter and length). However, the problem is far more
>>>>>>likely to be the inverter, which is a bit more expensive, equally
>>>>>>difficult to get (althogh maybe not for a Thinkpad), and much, much
>>>>>>easier to replace.
>>>>>>
>>>>>>For a Thinkpad and many Toshiba models, you can find used but
>>>>>>perfectly fine working inverters on E-Bay from $5 to $25 (new ones
>>>>>>would often be $30 to $80). The more common the laptop, the easier
>>>>>>it is to find an inverter for it.
>>>>>>
>>>>>>You can tell that the panel itself is ok if you can see a VERY FAINT
>>>>>>image of the screen. This can be very difficult to see, and you may
>>>>>>want to get a bright flashlight and shine it at the screen, or even
>>>>>>hold it right up against the screen (in either case, try both
>>>>>>straight and at an angle). However, even lacking that, from your
>>>>>>description, it's a problem with the backlight and not the actual
>>>>>>panel proper.
>>>>>>
>>>>>>Be careful working in this area, the inverter puts out very high
>>>>>>voltages (sometimes over 1,000 volts) that can be lethal.
>>>>>>
>>>>>>Don wrote:
>>>>>>
>>>>>>
>>>>>>
>>>>>>>Hi,
>>>>>>>
>>>>>>>I have a TP600X and when I first turn on the laptop, the screen
>>>>>>>turned on for maybe few seconds, then flickers for couple seconds,
>>>>>>>then it is off. I can use external monitor to use the laptop, and
>>>>>>>when I swap between LCD and external monitor, the LCD sometimes
>>>>>>>will come on for couple seconds, then it's off again. Is this a
>>>>>>>typical inverter problem? or should I just look for a LCD assembly.
>>>>>>>As the laptop is getting old I'm trying to save money and get only
>>>>>>>what I needed. Would really appreciate someone have similar problem
>>>>>>>shares their experiences with me.
>>>>>>>
>>>>>>>Thanks.
>>>>
>>>>
>>>>If there is a replacement inverter from the manufacturer, that will be
>>>>the replacement of choice. I've purchased several inverters on eBay and
>>>>with the exception on one, the balance were near the end of their useful
>>>>lives since they were parted from failed laptops. Inverters deteriorate
>>>>not only from the degrading effects of producing high voltage, but also
>>>>(perhaps mainly) from heat generation and placement in the bezel where
>>>>there virtually no cooling.
>>>>
>>>>Q
>>>>
>>>>
>>
>>