So I recently replaced the lamp in my Akai PT46DL10 46" DLP set. What happens is I turn on the TV, after about 25 sec. of the power light flashing green the lamp turns on and I get a picture, the power light is then a steady green. The set operates fine for about another 25 sec, and then the lamp turns off, but I still get audio. The audio continues for another 25 sec or so and then it turns off, and the red lamp light and the green power light are both lit up solid. Also sometimes I will turn it on and the power light will just flash and then the audio will come on but still no lamp. I know the bulb is fine because occasionally it turns on. I am leaning towards the ballast being bad. Any one else have any ideas? I am going to check that the ballast is getting the ~300v supply and ~5v control tomorrow. Note the TV is out of warranty, and I'd like to try to fix it myself before I call a service center.

Don't assume any bulb is good just because it turns on. A few models of LG/Zenith DLP's were infamous for their lamps to just shutdown.

Because you're lamp is turning on, you're obviously getting the 300v and the lamp control voltage. While it's still possible for the ballast to be bad I'd definitely begin any attempts at fixing this set by replacing the lamp.

Don't assume any bulb is good just because it turns on. A few models of LG/Zenith DLP's were infamous for their lamps to just shutdown.

Because you're lamp is turning on, you're obviously getting the 300v and the lamp control voltage. While it's still possible for the ballast to be bad I'd definitely begin any attempts at fixing this set by replacing the lamp.


Really, I figured that by turning on, it ment the bulb was ok. Interesting. I replaced my original bulb that said "UHO 120W Made In Taiwan" with a "UHP 100w/120w" that was made by Phillips. Is it possible that the new bulb is incompatible with the ballast?

Really, I figured that by turning on, it ment the bulb was ok. Interesting. I replaced my original bulb that said "UHO 120W Made In Taiwan" with a "UHP 100w/120w" that was made by Phillips. Is it possible that the new bulb is incompatible with the ballast?

It's certainly possible. Where did you get the new lamp from? Do you know for sure it's a correct sub for the original lamp? Since that's an Akai it's probably made by samsung (not for certain though).

It's certainly possible. Where did you get the new lamp from? Do you know for sure it's a correct sub for the original lamp? Since that's an Akai it's probably made by samsung (not for certain though).

A guy posted the equivalent samsung part number on a thread here on avs. I bought it from discount-merchant.xom Does 100W/120W mean that it is capable of running at either 100W or 120W? Also I was thinking that it might be thermal related. But I checked all the fans and they are all running and the vents all seemed clear. There is a temp sensor right above the lamp also, I tried removing it and moving it to a cooler spot, but that didn't really change anything.

I'm still not certain I'm understanding you. Was this a previous lamp replacement or was the lamp replaced now, when this shutdown problem started?

BTW, a fan failure won't allow the set to fire up at all. As for the temp sensors, I'd have to check the error codes at work but I'm not certain that the two lights lit indicate a temp problem.

Basically I bought the tv from a guy knowing the lamp was shot. The broken lamp that I pulled out said "UHO 120W Made In Taiwan". I couldn't find an orginal replacement for it. So I was told that samsung lamp# BP96-00224C was a direct replacement for the original. So thats what I have in there now.

Update: When I unplug the 5v control wires to the ballast and then plug it back in, the lamp immediately turns on, but then turns back off after 25 sec. or so. If unplug and then replug again I get the same thing. This kind of sounds like the ballast is bad. Anyone have any insight?

Lets say that my lamp requires 15kV to light up, but my ballast can only supply 5kV. Would the lamp start up at all, or would it start up and then shut off like mine does?

At 5KV the lamp would fail to fire properly. There are a couple LV control lines going to and from a ballast board. One is the lamp enable which tells the ballast to fire the lamp and the other is the lamp on line which tells the micro the lamp has succesfully fired. There are some dynamics with mercury halogen lamps that can cause them to misfire or incorrectly strike. Some of it is due to the timing of the lamp strike pulse. Some ballasts, while electronically wired the same as another ballast won't fire a particular lamp because the timing of the enable and pulse is off for the dynamics of that particular lamp. Some lamp manufacturers aren't that picky and their lamps will fire with just about any ballast, others require the exact ballast. Again I suggest to verify the lamps integrity by installing a known good lamp for that model. It's possible the timing of the lamp firing is not triggering the lamp on line at the right time causing the micro to not detect lamp on at the right time and then shutting the set down.

At 5KV the lamp would fail to fire properly. There are a couple LV control lines going to and from a ballast board. One is the lamp enable which tells the ballast to fire the lamp and the other is the lamp on line which tells the micro the lamp has succesfully fired. There are some dynamics with mercury halogen lamps that can cause them to misfire or incorrectly strike. Some of it is due to the timing of the lamp strike pulse. Some ballasts, while electronically wired the same as another ballast won't fire a particular lamp because the timing of the enable and pulse is off for the dynamics of that particular lamp. Some lamp manufacturers aren't that picky and their lamps will fire with just about any ballast, others require the exact ballast. Again I suggest to verify the lamps integrity by installing a known good lamp for that model. It's possible the timing of the lamp firing is not triggering the lamp on line at the right time causing the micro to not detect lamp on at the right time and then shutting the set down.

Alright, I'll give that a try. I know the specs of the bulb are the same as the original, but you never know. Also I found out that a new ballast is back ordered until the end of july :mad: I can see why people stick with name brands.

BTW, I checked a few Samsung DLP manuals today at work the the error code your AKAI is throwing is a bad lamp code.

BTW, I checked a few Samsung DLP manuals today at work the the error code your AKAI is throwing is a bad lamp code.

The is an Akai, built by DVLX technology. I am pretty sure samsung had no hand in this particular model. I finally got an exact replacement bulb for this set. Same problem as before. I may try the $75 for a new ballast, but I have a feeling that ballast is fine, and that the main processing board is telling the ballast to shut off. Either a sensor is telling it it needs to turn off or there is a problem at the board level.

It's a shame it's not a Sammie based unit. The fact that this is some Chinese manufactured knockoff is not a good thing, at least for trying to get parts for. Akai is distributed by ESI. I can tell you after dealing with them for awhile you'll be lucky to find anything available for it.

The technology is basically this dependant on who built that thing. If the unit strikes the lamp and it fires and the unit detects a problem somewhere else in the set it may shut the lamp down. Most name brands won't even bother to attempt to strike the lamp but cheaper ones will actually turn the lamp on before going into shutdown. Not an easy fix and it could quite possibly be the signal board with the micro on it or the Engine.

You might want to try Primus electronics, they tend to specialize in parts for off the wall LCD's or rear projectors.

I wouldn't waste too much time or money on it.

The lamp ballast is actually one of the few parts that is readily available for this set. I am going to have another look at the signal wires before I commit to the new ballast.