HP W1907V Squealing

[spleenharvester]

Hello!

I bought a HP W1907V for 30 quid. Got it today. Absolutely beautiful monitor and "works" fine but there's a horrible squeal.

There's seriously loud rattling/buzzing sound from one area and a really high pitch whine from another.

Does this sound like a badcapped case? Its brother, the W2207, seems to be a known badcapped monitor. So I can't help but wonder.

I've been trying to get the thing open for half hour.

[spleenharvester]

Re: HP W1907V Squealing

Okay, some update on this. I've got the thing open. The power board is a PTB-1773, the same type as used in the HP W2007.

All caps look fine visually. I'm pretty sure the squeal is coming from the big rectangular component near the inverter connections :/ where does it look most likely to be coming from?

This one:

http://www.lcdparts.net/Images/LIPS/PTB-1773.jpg

[Rtech]

Re: HP W1907V Squealing

Okay, some update on this. I've got the thing open. The power board is a PTB-1773, the same type as used in the HP W2007.

All caps look fine visually. I'm pretty sure the squeal is coming from the big rectangular component near the inverter connections :/ where does it look most likely to be coming from?

This one:

http://www.lcdparts.net/Images/LIPS/PTB-1773.jpg

Disconnect the lamps from the 4 sockets on the board, and then switch it on ????/

[spleenharvester]

Re: HP W1907V Squealing

Just did, it's completely silent without them.

[Rtech]

Re: HP W1907V Squealing

The Power supply on these models are excellent, and 95% of faults are caused by problems with the backlights and or the wiring to them,normally the top backlight being the culprit.Have you got a test lamp ??//to find if the problem is top or Bottom.Try putting in the Top pair only and see what happens ?? and then the bottom pair only ??, the lamps will only go on for a short time,but may give you an indication where to go next.

[spleenharvester]

Re: HP W1907V Squealing

No test lamp unfortunately. But I tried the top pair and the bottom pair separately and the hiss comes from the transformer in both tests.

[Rtech]

Re: HP W1907V Squealing

Then measure the Resistance of the secondaries on the transformer,if I remember correctly they should both measure about 630Ω, but both must be very close to each other.

[spleenharvester]

Re: HP W1907V Squealing

They are both very close to that indeed :p

[selldoor]

Re: HP W1907V Squealing

If the leads are long enough try swapping the top light leads and bottom light leads where they plug into the power board

[spleenharvester]

Re: HP W1907V Squealing

They don't seem to be unfortunately! Cheers

[spleenharvester]

Re: HP W1907V Squealing

Found something interesting, if the PCB is flexed slightly (by wiggling AC plug or CCFL plugs) the frequency of the hiss changes. Dry joint somewhere?

[Rtech]

Re: HP W1907V Squealing

Up the Creek without a paddle then.....You need a set of test CCfl's,as the fault is either both lamps/wiring,OR the Inverter part of the Board,only a good pair of Backlights or a Good board, can eliminate which is the problem,suggest a visit to a 'tip' maybe and try for a broken Monitor, 15",17",or 19", as long as one set works.maybe even a wanted Ad on Freecycle or Freegle,if you have one of them, as i don't know what part of the World you are in ??

[Rtech]

Re: HP W1907V Squealing

If its a 'Hiss' then Backlights would be my preferred option.

[Rtech]

Re: HP W1907V Squealing

You could try re-soldering the Transformer and around that area.

[selldoor]

Re: HP W1907V Squealing

Found something interesting, if the PCB is flexed slightly (by wiggling AC plug or CCFL plugs) the frequency of the hiss changes. Dry joint somewhere?

Unlikely - does the screen look pink at all? it sound as though one or more
bulb or its wiring is wearing out putting the transformer under pressure by moving the board you just change slightly the physical pressure on the transformer.

One thing you might try is to resolder the all the transformer pins.

The ccfl leads may be long enough to swap if you turn the board over?

[Rtech]

Re: HP W1907V Squealing

You can try swapping the leads over, but from the tests you have already done,I would not think it will make any difference.

[spleenharvester]

Re: HP W1907V Squealing

Screen is literally perfect, as is rest of the monitor, aside from this hissing issue. Such a shame, it's an amazing monitor.

Would it be worth just buying a replacement inverter board for ~£15 and seeing where it goes from there?

Also, would a faulty backlight make a transformer hiss? The hiss is definitely coming from the transformer and nowhere else.

[selldoor]

Re: HP W1907V Squealing

Post good clear pictures of the back and front of the power supply - we may be able to spot something you have missed.

[spleenharvester]

Re: HP W1907V Squealing

Yessir. Lemme know if they're not clear enough. http://imgur.com/a/xeZMO

[Rtech]

Re: HP W1907V Squealing

As I stated at the beginning 95% of faults are not the Board.I usually have one on Ebay, and then get people to test the backlights, and that is where the fault is.