PC Engine Backlight Tube

[Drumjay]

Firstly I would like to congratulate you all on this superb forum!

My first post! So please excuse any errors. I have read all the search topics but can't find my answer as yet.

So, here goes!

It's silly really because i do repair PC Engines for a bit of extra cash, but as yet I haven't found where I can actually source the PC Engine GT/ Turbo Express actual backlight tube. Capacitors no problem, all the mods under the sun! But the tiny tube that gives light is a mystery. I now have 4 units
all fully working, but with blown tubes. I can find a LED mod fix to elevate the problem. So I thought I would ask the experts!

And yes I have spent hours searching on Google for anyone who manufactures these, no luck.

Any help would be greatly appreciated!

[Drumjay]

Must be as rare as the console. Someone think of a LED Mod quick!

[papa_november]

Your only real solutions here:

    -Track down a model or three of ancient handheld TV that uses the same screen or backlight unit.
    -Figure out the model or formal size/voltage of the tube and work with tube suppliers to find an equivalent.
    -adapt an existing LED backlighting mod for some other console. The basic technique is pretty much the same.

[Duo_R]

How hard is it remove one of the tubes? I recall that something behind the screen holds a pretty big charge and can shock pretty good.

[grahf]

An LED mod is simple as pie. It's just a matter of hooking up some white LEDs to the right voltage. The biggest problem is arranging them in such a way that doesn't give you bright spots on the screen. This can be done with a diffusion panel, or by placing the LEDs "off screen", so that they shine in from the sides. You can probably find all the information you need over at the benheck.com forums.

[Duo_R]

Good advice grahf. Would the "tube" be the part that holds a good electrical charge? Has anyone removed one?

[Drumjay]

Yes I have removed them before, unlike the Sega Game Gear which are soldered into position they are are plate mounted and stuck by double sided tape to the mirror. Once you have cut the tape they just pop out. i have thought you could maybe re energise them using the existing parts, but still need to find a place. I Mod the Game Gear with Led's this is quite simple, no spots if you use a defused tube. The Pc Engine seems to use a plus/ negative tube, and a different way of using the power usage to the back light. I have tried various ways without success. I'm hoping someone here with expert knowledge of the Engine could find a way.

[Charlie]

The TE uses a standard cold-light inverter circuit; it's a bit kludgy considering today's technology but was probably fairly state-of-the-art at the time.  It generates a low-current voltage at about 200V.  That's why it has such a big transformer.

If you intend to use LED's, you'll have to bypass the inverter (or rip it out entirely) and add the appropriate circuitry, and of course come up with some kind of mechanical assemby to hold the LED's as well as diffuse the light.

If you do choose to rip out the inverter, at least you will have convenient installation locations for the LED circuitry.  You could even convert the existing contrast control into a brightness control.

Charlie

[Drumjay]

Thanks Charlie, that's shed some light on it it for me  :oops:

I'll have another go as I've 4 still sitting here in good condition but no tube, same not to get them going again.

[JohnnyPhantom]

Was there ever a solution for this? I have a Express with a dead bulb/tube as well. thinking of going LED but would love some advice or some pictures on how it should look from another modded system

[thesteve]

i have never had a bad tube in a GT/express
i do have screens (removed working for screen swaps)
LED mods are stupid simple, and can easily be adapted from one system to another.
EL and OLED backlights can also be done, but are harder to source.
i used a string of LED's pointing at the reflector on a DUO monitor
mounted LED's in a gamegear reflector, but wasnt happy with it (replaced it with the backlight from a back up cam monitor(edge lit LED))

[JohnnyPhantom]

I wonder if a Game Gear tube would work, I have several of those just hanging around my house... hmmm..
In the end (for me at least) this doesn't matter since this system is heading over to thesteve soon for a LCD upgrade but would be good to know incase my stock Express ever dies as well.

[thesteve]

the GG tube is too long
however there are more good tubes than good screens for now

[JohnnyPhantom]

the GG tube is too long
however there are more good tubes than good screens for now

Just the matter of getting my hands on a good tube

Since the screen in my to be modded/lcd upgraded express is going to be useless soon, I'll play with it and LEDs and see what I can do

[thesteve]

http://www.ebay.com/itm/281032612013?item=281032612013&viewitem=&vxp=mtr
EL backlight anyone