Sharp Nintendo Televison Help needed

[Reubensupernerd]

Hello all, I recently acquired a sharp nintendo television in next to perfect cosmetic condition (all feet intact, minor scratches, the button doors dont stay up on their own( push in connectors are broken)). If only it worked lol. When I push the power button, the channel light comes on and all the buttons work, including those that start the nes, but I can't get a picture on the tube. I haven't been able to test for sound yet. If you guys have any advice it would be greatly appreciated.
Thanks,
Reuben
EDIT: maybe you guys who read the thread on the Sharp nintendo tv know something helpful?

[bicostp]

You can't get a picture on it from the NES or the tuner?

If you look at the tube in the dark, can you see it light up even a little bit when you turn the unit on? If not, you might have to clean some connectors inside, resolder some points, or replace capacitors.

Do NOT take this thing apart until you've done some reading on how to safely work around CRTs. Besides the usual high voltage warnings, the thin end has a fragile vacuum seal which will render the tube useless if it gets broken.

[weaponepsilon]

I think its a lost cause and you should sell it to me!

Is there any way to test the monitor separately from the NES portion?

[Oracletriplex]

Just read up on it on Wikipedia.

Can this thing play NES games or Famicom games? And it's possible that the tube is toast, it is pretty old.

[Triton]

Just read up on it on Wikipedia.

Can this thing play NES games or Famicom games? And it's possible that the tube is toast, it is pretty old.

in my experience the actual tube is RARELY the failure point in older TVs, i had a General Electric 12" tv from 1956 and it worked just fine

[Reubensupernerd]

@bicostp just tested what you said, can't get any sort of light on the tube. But I also didn't hear that noise (which I associate (most likely erroneously) with degaussing) "bdunk-cha" that you hear upon turning on most older tubes. This leads me to believe that somewhere along the line, the high voltage circuit is A. not getting power (like a busted fuse or something B. cold solder joints on a capacitor or a transformer C. fried electrolytic caps (found a similar situation in my mitsubishi diamond from '96). I am not very experienced when it comes to fixing CRTs so any and I mean ANY documentation (on this unit or CRTs in general) and any pointers you can give me would be GREATLY appreciated.
@weaponepsilon I payed a fortune to get this shipped (not too happy about that lol ). Perhaps if none of my attempts to solve the problem succeed I'll sell it to you. The only way I know of to directly test the monitor is not all that direct, you can use a coax cable to send video through the tuner (which doesn't appear to be fried). I tried this with my TV signal (no luck) and with my super nintendo + rf modulator (also no luck). I did send a message to the person I bought this from asking about how he got the audio working, I'm currently awaiting a response.
@oracletriplex I believe the NES components are based on the NES-101 (second model nes, the toploader) and as a result it should play all region games, because the NES 2 doesn't have a lockout chip.
@triton

Just read up on it on Wikipedia.

Can this thing play NES games or Famicom games? And it's possible that the tube is toast, it is pretty old.

in my experience the actual tube is RARELY the failure point in older TVs, i had a General Electric 12" tv from 1956 and it worked just fine

^ this made me very hopeful/excited. Any advice you can provide on CRT repairs would be fantastic.
EDIT: LOL megapost

[bicostp]

Sounds like an internal connection or power supply issue.

When working on a tube, be very very careful around the neck and end. They're both relatively fragile parts, and the vacuum plug on the end is extremely easy to break. (If it's broken, the tube is rendered worthless.)

Also be very careful around the flyback transformer and the anode on the side of the tube. (It's usually under a rubber cap that looks like a suction cup, and the two parts are directly connected with a heavy wire.) These are the parts that carry lethal voltage. If you have to work near them, safely discharge the CRT following one of the numerous guides online. Most modern flyback transformers have bleed resistors in them which will dissipate the power over a course of hours, but to be safe either discharge or leave the unit unplugged for a couple days.

in my experience the actual tube is RARELY the failure point in older TVs, i had a General Electric 12" tv from 1956 and it worked just fine

I've seen a couple go bad. The tube in my SE/30 is very dark, even though the rest of the computer works perfectly. (The brightness and voltage cutoff knobs are adjusted all the way open, and you still can't really see it in a well lit room.) The capacitors and solder joints on the analog board all look good, so I'm assuming the tube crapped out.

[Triton]

not to say that the CRT cant go bad, but the failure points are typically what was mentioned above (flyback transformer and HV circuit, capacitors, solder joints etc)

edited for redundancy

[bicostp]

CRTs can and do go bad. I just swapped the one from that dead Classic into the SE/30 and it works like new again! The voltage cutoff had to be lowered dramatically because we maxed it to compensate for the bad tube, but once it went back to where it should be it was fine.

It's probably not the tube itself in the OP's case though; if it doesn't have any light at all the transformer or something on the HV side is bad. (Either that or the tube is really hosed.)