The power, volume, channel, and menu buttons doent work on my 1998 proscan ps50700

No, and it is not real easy to get into the advanced convergence menu to do it. A a question: on rear of set aside from model number is there a chassis number like PTK195?

I could be anything but mostly it will be its age, and if its never been cleaned out it could be the bulb failed, power board. dust build up can cause over heating of the parts. even damage them if the dust becomes damp. is there any lights flashing or any leds lite up ?

I'm having the same issue with our proscan 61 inch rear projection. It was made in 1997

Well, that's the front panel button.Try pushing each button until you know which one is the cause.Actually,you need to find someone to replace this button, because to replace this button,you need to open the TV case, that's why you need an expert to do this.

Hope it works!!!!

I found this solution on another review, hope it works
Model Number: Proscan 26" LCD HDTV w/ Built-in DVD Player26LB30QD "pro: good price, TV picture is clear and DVD player is compatible well.
con: sound noise
There was hum when I first turned the TV on, then I followed these instructions (found it from other review) to fix the hum issue:
1. Turn tv on
2. Input mode should be tv
3. Turn volume to zero
4. With remote enter 9 8 7 6
5. A menu will appear on left side
6. Arrow down to backlight and with right arrow key move number from 81 to 83, press menu button twice,
7. Turn up volume and listen if hum is gone."
It works,no hum."

the channel up button broke

Projection TV sets need to have all three colors - RED - BLUE - GREEN - lined up correctly on the screen in order for the video to look normal. When its out of alignment the video will look 3D, wavy, distorted, etc. Most of the time you just need to adjust your convergence in the TV menu. If you cannot adjust it in the menu - then your convergence is broken and needs to be repaired.

This is a very common failure on these projection sets and a fairly simple DIY fix. All projeciton sets including Samsung, RCA, Sony, Philip Magnavox, Panasonic, Pioneer, Akai, GE, JVC, Toshiba, and others at some point will have the same problem.

Common Symptoms include....

• Screen looks 3D
• Colors don't line up
• One or more colors can't be adjusted when using the convergence menu.
• Screen is bowed or warped.
• TV shuts off after powering on. Power light will blink. TV may also make a chirping noise.

Here are some photos of convergence problems.






Here is a quick test....

Using your original remote go-to the settings menu then goto the convergence section.

Try to adjust the red and then the blue convergence.

You should be able to move RED and BLUE in all directions - up, down, left, and right. And you should be able to get the grid straight.

If you can't move them in all directions or cant move them far enough your convergence chips are bad and should be replaced. This is a common problem.

Note: If you TV has as flash focus or magic focus button only try pressing the button. If it fails to fix the convergence your need to fix it. See below for a fix

CONVERGENCE SOLUTION

You will need to replace the convergence chips and possibly some convergence resistors and pico fuses.
This is a a fairly easy DIY job if you are handy and can follow directions. You can get complete repair kits from TvRepairKits.com or click here. They have put together DIY repair kits that include the OEM parts and step by step photo instructions for each repair. If you are not handy or can't follow directions we would suggest calling a shop.

on the schem i would take a guess and say location would be something like T4400 or T4401

The PS50700 uses the PTK195 series chassis. You can switch the TV to the video mode by pressing MENU, press channel down 3 times to highlight "4 Channel", press MENU, press channel down twice to highlight "3 List and Labels", and then press MENU. The current channel will be highlighted, and you will press channel down until you go below channel 1, which is where the video inputs are (VID1, VID2, FRNT). To exit, press MENU, choose "Exit", press MENU and choose "Exit" again, or just wait until the menu times out. An easier way is to get a universal remote that has an "INPUT" button.

what chassis is in your set,look at the rear panel for model and chasis type to help to diagnose fault