Gateway 2100

[davg]

Gateway 2100 powers up shows video than goes black I have replaced all caps but still no go. On the back of the board are 4 transistors 2 # BH 4214 (D405) and 2 # BE5G43 (D408) can someone tell me where I can find suitable replacements for these? and the spect. sheet

[davg]

Re: Gateway 2100

Ok I did find the Data sheet for these mosfet They are Alpha & Omega transistors. The AOD408 is a 30v 18A N-Channel and the AOD405 is -30v -18A P-Channel The AOD408 is now AOD484 and is available from Digi-key but I cannot find the P-Channel AOD405 Is it necessary to match the data exactly What would be a suitable replacement and can someone suggest a Canadian supplier.

[PCBONEZ]

Re: Gateway 2100

You may have bad lamps in that one.

[davg]

Re: Gateway 2100

You may have bad lamps in that one.

I never tested the lamps because it had the same symptoms as several other monitors I repaired by replacing either the caps or the transistors or both. I assume to much. Is this a common fault with this model?

[EGuevarae]

Re: Gateway 2100

I never tested the lamps because it had the same symptoms as several other monitors I repaired by replacing either the caps or the transistors or both. I assume to much. Is this a common fault with this model?

Not specific to the model, but it can be. I fixed 2 today with that symptoms . There were 4. One lamp was bad in all of them, and I just pulled the two working ones from two units to fix the other two. I ended with a happy friend and two free working monitors that just need some lamps.

My main question here is why you are changing them, did you test them and found them to be bad, or is just a standard procedure?

[PCBONEZ]

Re: Gateway 2100

I don't know that screen.
I'm just saying symptoms sound like lamps could be the problem.
Looks like you jumped from caps to IC's without checking the lamps.

According to this AOD405 crosses to a STU2030PL.


This crosses it to AOU405, CED3301, and CEU3301.

[EGuevarae]

Re: Gateway 2100

[QUOTE=PCBONEZ]I don't know that screen.
I'm just saying symptoms sound like lamps could be the problem.
Looks like you jumped from caps to IC's without checking the lamps.
QUOTE]

Exactly the same here. You didn't tell how you came to the conclusion that the ICs were shot.

[davg]

Re: Gateway 2100

[QUOTE=eguevarae]

I don't know that screen.
I'm just saying symptoms sound like lamps could be the problem.
Looks like you jumped from caps to IC's without checking the lamps.
QUOTE]

Exactly the same here. You didn't tell how you came to the conclusion that the ICs were shot.

Thanks Pcbonez and Equevarae since I am not a tech person and really don't know these circuits I assume failed caps or failed transistors and now failed lamps. I depend largely on this forum but learning as I go. Now I have to learn how to test, remove and replace lamps. great something new.

[EGuevarae]

Re: Gateway 2100

Now I have to learn how to test, remove and replace lamps. great something new.

Well, I found myself in the same situation a while ago. Lucky (?) me, I had a pair of CCFLs from an LCD panel with a burned (melted, in fact) Power supply.
What I did? I took an inverter from a neon light kit for a PC (dual output), soldered the output connectors of the dead PSU/Inverter on it, and installed banana connectors in the input side of it. It has a switch so I can connect the lamps and then turn it on. Here are some pics. The last thing I did was put back the inverter circuit in its little plastic case and install the banana connectors (not shown) to use with my test supply. Before the test supply, I used a power adapter for external hard drives that had an output just like the molex connectors from an ATX PSU. That's how I test the lamps most of the time.
The removal of the lamps, is another story. It varies with the LCD Panel model, and sometimes it is easy, sometimes is not. Just be careful if you remove them, as they are fragile (very fragile)

[davg]

Re: Gateway 2100

Well, I found myself in the same situation a while ago. Lucky (?) me, I had a pair of CCFLs from an LCD panel with a burned (melted, in fact) Power supply.
What I did? I took an inverter from a neon light kit for a PC (dual output), soldered the output connectors of the dead PSU/Inverter on it, and installed banana connectors in the input side of it. It has a switch so I can connect the lamps and then turn it on. Here are some pics. The last thing I did was put back the inverter circuit in its little plastic case and install the banana connectors (not shown) to use with my test supply. Before the test supply, I used a power adapter for external hard drives that had an output just like the molex connectors from an ATX PSU. That's how I test the lamps most of the time.
The removal of the lamps, is another story. It varies with the LCD Panel model, and sometimes it is easy, sometimes is not. Just be careful if you remove them, as they are fragile (very fragile)

Very creative my friend good job. What kind of voltage and amperage do these ccfl require? There must be some way to test them without removing them? Connectors is another issue of course these are different than the ones in a known good screen just my luck.

[EGuevarae]

Re: Gateway 2100

Very creative my friend good job. What kind of voltage and amperage do these ccfl require? There must be some way to test them without removing them? Connectors is another issue of course these are different than the ones in a known good screen just my luck.

Well. These pictures are from the project progress. Now I use it without removing the lamps. Almost all the panels I've seen have that narrow connector, but for those that don't, I have "adapters" built , again, from parts of dead panels. It might not be the best way to test lamps, but so far it has helped me a lot.
As for V and A ratings for the lamps, that is a really good question. I don't know.

[PCBONEZ]

Re: Gateway 2100

oops

[PCBONEZ]

Re: Gateway 2100

Voltage is like 800-1800 VAC, usually in the 30-60 kHz range.
Amps though is only like 5 mA.

.

[davg]

Re: Gateway 2100

Voltage is like 800-1800 VAC, usually in the 30-60 kHz range.
Amps though is only like 5 mA.

.

So the inverter board determines the voltage. I guess I will have to find a working board and make some adapters for these lamps.
Just to confirm that these symptoms reflect failed lamps. The unit turns on and shows video but than goes black (on light stays green) Shine a bright light into the screen shows video. This could be among other things Failed caps, Failed Transistors. Failed lamps or all of the above???

[EGuevarae]

Re: Gateway 2100

It could be all, or a combination of some, or just one..... that's why you first check visually for bad caps, then for shorts, open fuses, then the lamps with a good inverter or the inverter with good lamps, and so on ....

[davg]

Re: Gateway 2100

It could be all, or a combination of some, or just one..... that's why you first check visually for bad caps, then for shorts, open fuses, then the lamps with a good inverter or the inverter with good lamps, and so on ....

Gotya thanks for butting it in perspective. I have revived a dozen or so of these and to date all have been to replace the caps. I have several more showing much the same symptoms that I know caps is not the problem so now I have to extend my arising and maybe my equipment. Lots of good help here if one can ask the right questions. Thanks to all.

[davg]

Re: Gateway 2100

You may have bad lamps in that one.

Thanks again PCBONEZ and equevarae for your great advice that gave me reason to take a second look. While trying to find an adapter for these ccfl I discovered that one of the pins was bent. I straightened it put back together and all is well. Goes to show never be to hasty in your decisions but check all possibilities. Many many thanks

[EGuevarae]

Re: Gateway 2100

Thanks again PCBONEZ and equevarae for your great advice that gave me reason to take a second look. While trying to find an adapter for these ccfl I discovered that one of the pins was bent. I straightened it put back together and all is well. Goes to show never be to hasty in your decisions but check all possibilities. Many many thanks

Good for you. Now another one saved from the landfill.
And you learned something along the process, so double benefit.

[PCBONEZ]

Re: Gateway 2100

Congrats!

[davg]

Re: Gateway 2100

Ya and again thanks to you both and all the good people on this forum