Sanyo PLC-SU50S multimedia Projectror problem

str-z2156a

hi all colleagues
i have this sanyo LCD projector with the following fault ...
when u press the power button the power led lights green and the cooling fans start to work but the main projector lamp didn't light on , after a few seconds ( 5-10) the green led lights red but flashing ( on-off) for about one min , during this one min the cooling fans work properly and can hear them before the unit go into stand by with a steady red led power indicator .
if u turned the projector on again it do the same trip but never have the main lamp work.
i have both 15.5V and 6V outputs from power supply , so i assume that the main switching power supply based on Ic631 = STR-Z2156A is working properly and the problem may be in one of the following :
defect Lamp
defect lamp ballast circuit wich include the inverter
defect power fail control circuit based on IC621=FA5502M
this is the first time i work with such a multimedia projector and just need any help or tips if any one has work with that before .
wanna know how to isolate the faulty stage here and if there any tips that may help in that .
i do appreciate any help or response and i do have the service manual for this unit
thanks in advance
Kind Regards

Hello!

I don't know this projector in detail so I can't help you with a specific hint, but I may help with a more general approach.

I think there is a discharge lamp in the projector. Some projectors have bulbs with a wire, but most of them use discharge lamps. These discharge lamps have an ignition voltage of several kV, could be around 5 to 10 kV, sometimes even more. When the arc is ignited, the voltage is reduced to several tens of Volt, around 60 to 200 depending on lamp type and power, with a current between about a few hundred mA to a few A, also depending on power of the lamp. The voltage applied to the lamp is typically AC, not DC.

If the inverter is damaged no ignition voltage is generated, therefore the lamp won't be lit. If you have the proper tools you can check if the ignition voltage is generated.

But be aware of the fact that several kV can be present at the lamp!! Touching the voltage can be lethal!!!

So you need the proper voltmeter to measure a voltage in the area of 20 kV at least to test if the ignition voltage is applied at all. If it is present, and the lamp won't be ignited probably the lamp is damaged or burned out. If the ignition voltage is not present then the electronics is bad, could be a deaf capacitor (mainly electrolytic cap) or a melted down transformer. In case the transformer is broken there is only little chance to get the unit working again unless you can use a transformer from a broken unit with another failure. These transformers are usually custom devices.

Again: check what you are doing, the voltage generated will be hazardous!!

Also be warned that the UHP lamps have a pressure inside up to 200 bar or even more, so when playing around with the lamp wear safety glasses. This enhances the chance of waking up in the hospital with intact eyesight.


CU

hi pit
thanks alot for that so much helpful info , i was really suspecting the discharge lamp but has no way to test the lamp or the inverter circuit as all i have is only a multimeter that can measure DC voltage up to 1000V and DC voltage up to 750V
and this is the first time for me to come across this unit for repair and even the lamp is not easy available where i'm living :lol:
this would help testing the inverter at least , we still work with tubes and still had more time to have LCD and plasma technology for repair .
well, i was thinking about building an inverter unit to test lamps like this one but u said the transformers used in that unit are custom type , so i can't make a general purpose test unit ?
if u do have any general purpose inverter unit please post or any link online that may help doing that unit .
i'm still searching a lamp to test the inverter and electronics part or an inverter to test the lamp , as i've said before the lamp is not available here , but still searching it from the major electronics suppliers on my country .
thanks for any help or hints that may given
Kind Regards

Hello!

Actually the current is controlled that is flowing through the lamp, so the inverter circuit controls a constant current through the lamp, at least when the lamp is ignited.

To have an universal inverter for lamp test purposes you can build one yourself with adjustable current control, so you can set the current according to the lamp's specs.

For high voltage transformers I have no specific source other than the usual ones, you may try HR-Diemen for example, or Coilcraft, Top Magnetics Corp. etc.


CU

hi pit
thanks alot for ur valuable information , i do really suspect the lamp and tried to get one from here but couldn't .
do u know any soruces for those lamps , the lamp i have here in this model is made by OSRAM , germany and has the following info
p-vip 200/1.0 p215
1AV 4T 30B08100
and what's the cost per one if u have any idea or any one who can help in this
thanks in advance
Regards

Hello!

The lamp is available in the USA from

http://www.audiogeneral.com/Sanyo/Accessories.html
for 425 USD.

In Germany
**broken link removed**
for 478 Euro.

I don't know in which country you are?


CU

hi pit
thank u very much for this great information , but unfortunately this unit will not be repaired because of the high price of the lamp
i live in egypt any way and the cost of the lamp is very high for such a repair , but sueful experment and will not accept such a unit for repair any more :lol:
Kind Regards

Hello!

All the projectors with UHP lamps have the problem that the lamp is very expensive, so normally if the lamp is dead the whole unit is assumed to be dead, at least economically.

Projectors which are more expensive have a cheaper lamp inside, some projectors have standard halogen metal lamps which cost only a fraction of the special UHP lamps. Of course most people don't look at the price of a replacement lamp when buying a projector, they look only at the price of the projector.

CU