Inverter module thanks to ilikesteel

[budm]

ilikesteel found this great unit on the web, it will good for testing the lamps (4), can't beat the price. Cost less than one replacement transformer.

[momaka]

Re: Inverter module thanks to ilikesteel

I was actually thinking of buying an inverter like that for a Philips 190S5 19" LCD monitor that I found recently. Except I was thinking of buying one off of ebay (the Chinese ones on ebay are similarly priced and don't look that bad either). What you posted is probably better, though.

[budm]

Re: Inverter module thanks to ilikesteel

They have more on EBAY:
http://www.ebay.com/sch/i.html?_nkw=...RTER&_osacat=0

[tom66]

Re: Inverter module thanks to ilikesteel

Do these inverters work with just one bulb, or do all four need to be plugged in?

[budm]

Re: Inverter module thanks to ilikesteel

All four lamps have to be good, it uses the same detection to know if the lamps will fire up and stay lit or not. This will just help you narrow down the problem to find out if you have bad lamps or bad inverter board. When I have bad lamps, I will inspect all the lamps any way.

[momaka]

Re: Inverter module thanks to ilikesteel

Do these inverters work with just one bulb, or do all four need to be plugged in?

As budm said, all 4 lamps need to be good and plugged in. That said, they do also sell 2-lamp and single-lamp inverters if you need to drive just a single CCFL.

Looking at close-up pictures at most of these inverters, they seem to be using a push-pull design rather than the old Royer oscillator - and that's good in a way. At least from my observation, push-pull designs are a lot more robust. However, one potential problem they have is that multi-lamp inverters usually drive all CCFLs at once and if one CCFL is bad, the whole inverter shuts down and you cannot disable parts of the inverter to let the other CCFLs run. With Royer oscillator, the most common config is 2 CCFLs/inverter transformer. In a 4-lamp inverter, you can sometimes disable half of the inverter and just use the other half. That's what I did with my Dell E193FPc after it blew the new replacement transistors for the lower inverter despite the transformer joints being good.

[budm]

Re: Inverter module thanks to ilikesteel

No body that I know of uses the Royer Oscillator setup any more in their design due to the newer PWM IC, the Oscillator is done inside the IC instead of depending on the Tuned circuits of the output stage with big high voltage tuning caps.
It is also corrrect that you cannot disable one set of the lamp with this new design as momaka indicated, I did the same on those BenQ designed used in HP and Dell to run just two lamps.
Funny thing is that I see some of these 22" wide screen Dell and HP are using only TWO lamps! to keep the price down.

[jetadm123]

Re: Inverter module thanks to ilikesteel

Can't believe the price of these inverters on eBay. And it includes free shipping! Man, if I had a bad ccfl controller chip or inverter transformer I couldn't source, I'd probably try and fit one of these boards into the circuit.

[budm]

Re: Inverter module thanks to ilikesteel

I know, it's cheaper than a replacement transformer! and free shipping!

[retiredcaps]

Re: Inverter module thanks to ilikesteel

Can't believe the price of these inverters on eBay.

The inverter transformers, in bulk (50 or 100), go for about $1 each. I have seen them on Chinese websites.

[momaka]

Re: Inverter module thanks to ilikesteel

Man, if I had a bad ccfl controller chip or inverter transformer I couldn't source, I'd probably try and fit one of these boards into the circuit.

I'm actually very tempted to do that right now with my Philips 190S5 19". There's lots of discoloration near the inverter traffo and everything else checks out fine. All it would take is to buy one of these new inverters, dremel away the old inverter off of the power supply PCB and just hook up the new inverter.

I think we are slowly falling into slavery to the cheap Chinese electronics. The point where it's cheaper to replace the whole thing than it is to fix it on the component level is nearing.