Dell 1526 noise at PS board not fan?

Lately after installing Windows7x86 Ult Sp1 and updates I hear the fan start up and shutdown. But along this I hear a high pitch whine like a PS going bad or something. Not anything along the fan itself because I switched with another working fan and the same high pitch whine comes back after being on. Is the PS board connector going bad on it? I have another spare used one and if the sounds continues I might just switch those two parts to see if that is the problem. I eliminated motherboard as that is A19 and PS as I used two different one and running on battery it has the same high pitch whine as well near the fan location. It sounds like a overheating alarm whine but the computer still runs and doesn't shutdown or get overheated to any substantial extent. Anyone with a Dell 1526 AMD and bios updated run into this problem?

 

it sounds (no pun intended) like it could be the LCD inverter board.

 

hmm...so I should switch the inverter board then to test if that is the case? Have you heard similar problems like this before? But the sound if you listen for it sounds near the fan and PS board side not near the middle of the LCD where the inverter would be though? This is the first time I had this and it doesn't identify itself and making diagnosis not so easy.

 

it is possible it is coming from the power supply power board, but I have found most noises like a buzzing sound tend to be from a failing inverter in these CCFL generation of laptops.

The Inverter would be a easier and cheaper fix. so hope that what it is.

 

It just started recently as well...and that whine or noise is pretty loud in a quiet room. When first hearing I was like what is that....??? But how come it sounds like is coming from the PS board side or near there? I thought the inverter was near the center of the display under the LCD?? But one of me 1525 Intel hasn't made this noise that I can hear.

 

well as I said it is possible it could be from the power supply, all I would do to start is remove the front bezel and try to rule out the inverter which is the cheapest fix.

you can also try a different ac adaptor if you have a spare and see if anything changes.

if its the power circuit on the main board it could be a bit more involved repair.

 

I try that with different PS and see but I think I have a two extra inverter that might work that I might try as well but I got it back and will give it a burn in test to see again. But I also do have 3 new fans to replace should it be the fan as well...

 

Ok, reporting back I did switch the inverter and the high pitch whine has disappeared but you can still hear a small but audible whine sound still. The PS board is a separate unit which if needed to replace wouldn't be to hard to do. But switching the inverter for another used spare has stopped the whine but you can hear it is still there if you did a reboot or cold start and or restart. So does this mean I should try for a "New" inverter and see if the problem isn't inverter isolated?