Hi all.
I am having a problem with my pj.
Since yesterday the lamp doesnt switch on anymore but when measuring the voltage over the lamp i get an voltage of approx 340V DC.
It looks like the high voltage to light the lamp is gone and so the lamp doesnt start up.
Is there anyone who knows what could be wrong?
PS: When i connect the bottom two terminals on the lamp connector in the pj then it starts up and i get a picture when i shine a bright light into the space where normally the lamp sits.
This means that the pj is still working.
Could it be that only some component on the powersupply board is broken?
Please reply , i want to see the soccer on the big screen again.
I am having a problem with my pj.
Since yesterday the lamp doesnt switch on anymore but when measuring the voltage over the lamp i get an voltage of approx 340V DC.
It looks like the high voltage to light the lamp is gone and so the lamp doesnt start up.
Is there anyone who knows what could be wrong?
PS: When i connect the bottom two terminals on the lamp connector in the pj then it starts up and i get a picture when i shine a bright light into the space where normally the lamp sits.
This means that the pj is still working.
Could it be that only some component on the powersupply board is broken?
Please reply , i want to see the soccer on the big screen again.
hi mill
sounds like you will need to find a spares pj and swap out the ballast/lamp psu
if you can find a spares pj on ebay or somewhere, having all those bits available could be quite useful to you for some time
good luck
matt
sounds like you will need to find a spares pj and swap out the ballast/lamp psu
if you can find a spares pj on ebay or somewhere, having all those bits available could be quite useful to you for some time
good luck
matt
Hi
With the lamp in place, on start-up have a close look down the lens,
you should see the spark trying to ignite the lamp, as this sparks, the main fan will speed up, enough to notice. If this happens the PSU is faulty, If it does not speed up the problem lies in the Mainboard.
The most common fault with these pj`s is the electrode wear inside the Gas Discharge Tube, It`s this small component that builds up the voltage (2000-2500 V) required to kick start the lamp.
The GDT is 8mm in Dia and has a lead coming out both ends, that are soldered to the PCB, the GDT sits under the long Red Coil on the upright PCB. They only cost around US $2.50
Could i ask you to explain what you meant by
" When i connect the bottom two terminals on the lamp connector in the pj "
Do you mean you just bridged the bottom two connectors together ?
With the lamp in place, on start-up have a close look down the lens,
you should see the spark trying to ignite the lamp, as this sparks, the main fan will speed up, enough to notice. If this happens the PSU is faulty, If it does not speed up the problem lies in the Mainboard.
The most common fault with these pj`s is the electrode wear inside the Gas Discharge Tube, It`s this small component that builds up the voltage (2000-2500 V) required to kick start the lamp.
The GDT is 8mm in Dia and has a lead coming out both ends, that are soldered to the PCB, the GDT sits under the long Red Coil on the upright PCB. They only cost around US $2.50
Could i ask you to explain what you meant by
" When i connect the bottom two terminals on the lamp connector in the pj "
Do you mean you just bridged the bottom two connectors together ?
Hi codepuncher
Yes i measured the bottom two terminals on the lamp and it is 0 OHM so i just put a wire in the bottom two terminals in the pj and started it up and it does all the startup sequences then i used a halogen light and got a picture on the screen.
This was the infocus settings menu.
With a video signal i get a picture too.
The only weird thing is that i have DC voltages over the lamp and it is supposed to be AC.
That is why i thought is would be the mosfet that is broken.
I will have a look at the component you mentioned to see it it is faulty.
PS: i just had a look in the lens an couldn't see a spark when it started up.
Yes i measured the bottom two terminals on the lamp and it is 0 OHM so i just put a wire in the bottom two terminals in the pj and started it up and it does all the startup sequences then i used a halogen light and got a picture on the screen.
This was the infocus settings menu.
With a video signal i get a picture too.
The only weird thing is that i have DC voltages over the lamp and it is supposed to be AC.
That is why i thought is would be the mosfet that is broken.
I will have a look at the component you mentioned to see it it is faulty.
PS: i just had a look in the lens an couldn't see a spark when it started up.
From what i`ve heard..(sorry dont know where this is measured)
There is a sustaining voltage generated which starts at 120 volts DC then steps down to around 40 volts DC after current draw is detected.
There is a sustaining voltage generated which starts at 120 volts DC then steps down to around 40 volts DC after current draw is detected.
What about the fan speed ?
Again i`ve heard ... but not tried it.
To prove it`s a faulty GDT - under controlled conditions !!
You can fashion an air gap replacement that will work for a while, with two stiff wires separated by about a paper thickness.
Again i`ve heard ... but not tried it.
To prove it`s a faulty GDT - under controlled conditions !!
You can fashion an air gap replacement that will work for a while, with two stiff wires separated by about a paper thickness.
Hi codepuncher.
The voltage on the terminals when the lamp isn't in is 340V DC and after about 20 seconds it falls to 80V DC.
So it might be the GDT.
Have to open up the pj agan.
Could you please tell me where i can buy them?
Cheers mill.
The fan goes to full speed and i will try the wire airgap method you described.
The voltage on the terminals when the lamp isn't in is 340V DC and after about 20 seconds it falls to 80V DC.
So it might be the GDT.
Have to open up the pj agan.
Could you please tell me where i can buy them?
Cheers mill.
The fan goes to full speed and i will try the wire airgap method you described.
I found the invoice from Digikey.com
They have an online sales `chat window` where you can order through, the component was only £2.22 but it cost me £22 for shipping
so if you can, ask a friend in the US to buy it and post it to ya.
The part is
B88069X2190S102
Surge Arrester 2500V GasTube 2P
They have an online sales `chat window` where you can order through, the component was only £2.22 but it cost me £22 for shipping
so if you can, ask a friend in the US to buy it and post it to ya.The part is
B88069X2190S102
Surge Arrester 2500V GasTube 2P
Thank you very much for that info and your help codepuncher.
Will try the wire gap first and see from there.
Cheers, mill.
🙂
Will try the wire gap first and see from there.
Cheers, mill.
🙂
Hi codepuncher.
I did the wire trick and presto the lamp worked!!
Thanks very much for your advice.
Now i have to get an Gas Discharge Tube.
Thanks again.
I did the wire trick and presto the lamp worked!!
Thanks very much for your advice.
Now i have to get an Gas Discharge Tube.
Thanks again.
yes that is how i did it but there must be a light sensing device in the light path.
When the pj doesnt detect light then the colourwheel will stop.
Just try a 12V 50W halogen spotlight and you will see that the colourwheel will start again
I had an 100 inch picture just by using the halogen light.
Not very bright but still good.
When the pj doesnt detect light then the colourwheel will stop.
Just try a 12V 50W halogen spotlight and you will see that the colourwheel will start again
I had an 100 inch picture just by using the halogen light.
Not very bright but still good.
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