xabin

If there is on Ebay, my search for them hasn't come up with anything under $50 that isn't untested. https://www.ebay.com/itm/ONE-Genuine-Texas-Instruments-TI-UM1381-Video-Modulator-Switch-TI-99-4A-TESTED/143039629142?hash=item214dd38756:g:TZUAAOSw4IVcBtTd These are tested RF modules, so if it is the RF we have that's the problem, we might look into getting one of them.

https://www.ebay.com/itm/Vintage-Texas-Instruments-TI-99-4A-Home-Computer-with-power-adapter/163636035030?ssPageName=STRK%3AMEBIDX%3AIT&_trksid=p2060353.m1438.l2649 Someone directed me to this auction. It seems interesting, and if we can't get our TI working regardless of what we do, we'll look into getting it as a last resort. We do like that it's within an hour or so away from us, so we can just go down to get it, if we buy it.

My boyfriend's dad is a Ham Radio expert, gives classes on it, so that's how we know about our local Hamfest. Dunno if he'd know anyone who could help us out, though; he tried himself, since he knows something about electronic repairs, but he didn't get far with it, sadly.

It's fine. We're in the Mshiana part of Indiana, and we do have a Hamfest in the area (about an hour away), so...

Okay, make sure it is the RF that's the problem first; before you mess around with the other stuff. Don't be like my boyfriend and me, please : /

We have that kind of problem, too. No one told us that the RF modulator were flaky. We'll feel really dumb if it turns out it is the RF modulator, this time... To the OP: Are you having the same visuals we're getting, ie. snowy/black screen with an audio buzz?

If we can't get this thing to work, my boyfriend is insisting we return everything we were given by you guys back, since it wouldn't be right in his mind to keep it without a working system. I kinda have to agree, but it's up to you guys what you'd like us to do.

The guys at the place we took it down still can't get it to work, so we're going to try one more thing, and have them try the composite cable we have. If that works, then we will need to get a working RF terminal, since we can't seem to get the composite to work on either of our TVs.

I wouldn't mind seeing someone port certain games to the TI, like the original LaMulana.

So, they still haven't figured out what's causing the issue, but they have cleaned the boards and will inspect each connection, to make sure they work. They said that diagnosis would be $20, so I hope it doesn't go much over that...

We made sure to put it in the clamshell first before putting it in. And we are using an RF Modulator box with a balun to connect to the TV.

I'm not sure. How would we find out? We would use the composite cable I got for it, but the TV we have to test with it we can't find the remote for, so we can't switch it to AV mode.

Yeah, it is.

We dunno if what we did caused it or not, but we DO know that it was working fine, after we put RickyDean's parts in, until we tried playing Jawbreaker 2. We did notice, though, that when we took out Donkey Kong to put Jawbreaker in, we had to manually reset the console instead of plugging the cartridge in resetting it automatically, and the version of Donkey Kong we got has a rattling in it, which we can't open it up to check out, so...

After the issues started up again? No, we just get white snow and a buzzing sound.

When we first put the new parts in, it worked, and we got the Demonstration and Donkey Kong cartridges working. But when we put in Jawbreaker, it started up, then froze, and we had to restart it, but when we did, and from then on, it comes up white snow with a buzzing sound (not black screen, sorry, white snow, for the most part). We've taken it down to the local retro game store to see if they can diagnose and repair it. We know it has to be something we did that screwed it up, because until we tried playing Jawbreaker, it was working fine.

Nothing seems to be fried, this time. We plugged it into a multi-tap wall socket with a surge protector. As I said, it worked fine, until we tried putting in Jawbreaker 2, then it froze upon startup of the game, and now it's giving us a buzz with black screen.

One step forward, two steps back: we got the stuff from RickyDean, and after putting it together it worked for a while, but then it locked up when we put in Jawbreaker 2, and now we're getting black screen with buzz. Also, the I key on the new keyboard we got wasn't registering when we tried it while it was working, so...

He mentioned that we needed thermal paste for the reassembly, so I'm assuming it won't come with one, or if it does, it won't have thermal paste on it.

Managed to get a thing of thermal paste at BestBuy, yesterday, so we should be ready to go for when RickyDean's package gets here.

Great. Well, we didn't fry the keyboard, since it wasn't plugged in when we made the tests, so that should be good. RickyDean is offering to throw in a power board with the deal, so that SHOULD take care of everything. We really hate to do this kind of stuff to you guys, but at least this time we can contribute something to repay the generosity.

What does the SN74LS194AN chip do? That's the one that sparked on us, during the test.

It's been an adventure, I'll say that. We never expected this kind of help from the TI community, at all; we thought we'd get a little bit of advice, if that, and a whole lot of pointing to Ebay auctions for parts. The fact that we got so much more is why we're dedicated to getting this thing up and running; to make sure all of your help doesn't go to waste.

Perhaps. Damnit, this is turning out to be a nightmare for us..

We're already getting so many parts to refurbish this, so it's not really "our" TI, anymore, but the community's. We don't want to just ask for another handout like that, though; as we said, after all of this trouble, we feel like we should at least pay for the shipping for any future parts we get from others. Also, I did find a parts TI online on Ebay, but got outbid at the last second, and the next lowest priced one isn't going to be done for at least 3 days, so we're going to have to do some looking around. It'll take some convincing, but I think I can talk my boyfriend into having us take the TI down to the local vintage game store to at least try and diagnose exactly what the problem is (we mentioned it when we last went there, and they suggested we bring it over, since one of the owners' dad had one); dunno how much it'll cost, but if we can get a solid idea of what is going wrong and what needs to be fixed/replaced, we should be able to do more to tackle this problem.