TG16 Blank Screen

[fwonkas]

Hi — I'm hoping someone can help me with a problem I'm having with my TG16.

A few months ago it suddenly stopped working. When I try to turn it on, it gives me a blank screen. Usually white, but sometimes pinkish or yellow. Occasionally it will show some odd dotted patterns.

I've tried it with numerous games with the same result. I've tried fiddling with the hucards to see if maybe there's a bad connection and nothing seems to help

So earlier today I recapped it, but I'm still seeing the exact same problem.

Is there anything else I can try? Does anyone have any idea what might be causing this?

Thanks!

[bozo55]

Try cleaning the Hucard slot.  Take a coffee filter and cut it with scissors to match the width of a Hucard.  Douse the coffee filter with rubbing alcohol and wrap it around a Hucard.  Remove and reinsert the card repeatedly.  See if any dirt or goop is coming out.  Repeat until clean. Retest.

[NecroPhile]

It's possibly still a cap problem (bad cap, bad connection, etc.) or a trace damaged by leaking cap juice that needs repair.

[MNKyDeth]

It is a good idea on that coffee filter.

But since the contacts are metal and the corrosion that naturally forms on them is carbon I would think buying a huge eraser and cutting it down thin enough but long enough to stick out of the end of the slot and push/pull it in and out a couple of times would clean the contacts. I mean... erasers are made to get rid of carbon... it's what pencils are made out of.

I guess I should also mention I have always used erasers to clean the contacts on the HuCards themselves when there gets to be a lot of buildup. You can also use the eraser for the little slot cars to clean the metal contact pads. Erasers are awesome.

[fwonkas]

Question... are you using the RF out or do you have a means to use A/V?

I am using composite, yes. I got the same results when trying RF.

[fwonkas]

It's possibly still a cap problem (bad cap, bad connection, etc.) or a trace damaged by leaking cap juice that needs repair.

FWIW, while recapping I checked each cap as I removed them with a capacitance meter. They all appeared to be correct.

I did not replace the cap near the power plug or the cap in the RF unit.

[fwonkas]

Try cleaning the Hucard slot.  Take a coffee filter and cut it with scissors to match the width of a Hucard.  Douse the coffee filter with rubbing alcohol and wrap it around a Hucard.  Remove and reinsert the card repeatedly.  See if any dirt or goop is coming out.  Repeat until clean. Retest. 

Thanks! I will give this a shot tonight.

[bozo55]

I don't think I've heard of a confirmed case of TG16 cap fubars before, but a bad contact in the hu slot has been known to produce many nice full-screen color effects.  I'd never thought to try a coffee filter like that. Good idear, bozo.

I can't take credit for that one. I got that idea from a Turbo repair video on YouTube.  I'm having trouble finding it again but if I do I'll post the link.

Edit: Found the video

https://www.youtube.com/embed/qS-Iydy7TMU

The reason why the hu card slots can mess up is because the plastic sleeves can leave nasty, sticky goop on the card contacts when stored improperly.  I bought an arcade card duo off eBay and it had this problem. It took a lot of q tips and rubbing alcohol to get it clean. Make sure none of your hucards have sticky contacts before using them.

[fwonkas]

I tried the coffee filter trick. The console slot appears to be clean — no gunk came off at all after repeated tries. I even tried three filters at once.

I'm still just getting that blank (almost always white) screen with no sound.

I tried looking at the slot head-on with a bright light. As far as I can tell the contacts all looked fine.

[bozo55]

That's too bad.  I'm outta ideas.  How about testing your power supply with a multimeter to see if you're getting the proper voltage and amperage from it.

[fwonkas]

That's too bad.  I'm outta ideas.  How about testing your power supply with a multimeter to see if you're getting the proper voltage and amperage from it.

I did check the voltage coming out of the power supply last night. I believe it's supposed to do 10.5v, right? When testing just the power supply (not plugged into the console) it was showing about 14v.

This didn't surprise me too much, since I know that some power supplies will show a higher voltage until they are under load. Maybe that's not the case with the TG16 power supply?

The other day I checked the 7805 voltage regulator and it appeared to be outputting about 5v.

I didn't check the amperage. I'll try that tonight.

[Keith Courage]

double check that the chip card slot pins do not have any cracked connections. If they turn out to be good then unfortunately it sounds to me like you either have a bad chip on your motherboard somewhere or broken traces in between one-chip or another. get a hold of thesteve to repair it for you. he is best at figuring out these issues when dealing with bad chips or traces.

[thesteve]

good bet on traces
the results are the same for all cards its likely an issue with the CPU connections(or chip)
color encoder and grafix chip failures generally wont generally change color or give dots

[fwonkas]

good bet on traces
the results are the same for all cards its likely an issue with the CPU connections(or chip)
color encoder and grafix chip failures generally wont generally change color or give dots

So should I just go nuts with my multimeter to try to find broken continuity? I'm not sure where to start.

Good to hear that it's likely not a bad chip. The last few times I tinkered with it I was only getting a white screen, if that's an indication of anything.

[LostFlunky]

This is from a few years ago - I still haven't fully resolved this issue - it works flawlessly with the games in the first image, and not at all with the games in the second image.  I just assume it needs a new cart slot, or a slot refurb...  The odd thing about it is the games themselves - all the titles that wouldn't work (save for Bonk III) are earlier titles and all the ones that do work are TTI releases... 

I have a non-working TG16 that has been sitting in a box for years...

When I bought it, it would seem to work for a little while and then stop, and nothing I could do would get it to work again... It was always the same thing on boot - a solid coloured screen, usually light blue or dark green.

I decided to pull it out of hibernation and do some troubleshooting. I grabbed 2 HuCards off the shelf (Bomberman 93 and Bloody Wolf).

Bomberman 93 loads up and plays with no issues.
Bloody Wolf will boot up to a garbled startup screen and become unresponsive after that.

Looking at the contacts, it seems that Bloody Wolf must be thinner, as the contacts hardly move when the card is inserted, but the Bomberman 93 card causes the contacts to bend all the way as it is inserted and then stop about half way in their positions.

So, I gave it a good cleaning.  No difference.

So I grabbed a big mitt full of games to test.  With interesting results.

The first picture is of the games that boot up without issue.  The 2nd is of the games that either will not boot at all or may boot to a garbled title screen.

[thesteve]

so its working perfect on some cards?
could be an upper address line or bad work ram

[fwonkas]

I've only got 3 cards and a Turbo Everdrive. None of them work.

[nico868]

Hi,

I am bumping this thread for advise because I have a very similar problem on a Duo-R. Most of the HuCard will load with no problem but one will always fails (Yokai Dochuki) and show a white screen sometimes with a backgroup sound (kind of beeeeeeeeeeeeeeeeeeeeeeeeeep).

I know the HuCard is not the problem because I have 2 copies of Yokai and they load perfectly on my CoreGrafx. I have tested about 10 HuCard and Yokai is the only one to exhibit this problem so far, but I did not have time to test more.

I tought it could be a bad solder on the HuCard connector so I used a rework station and the hot air gun on the solders. Strangely the HuCard will load just after but when everything cools down, I get again the white screen.

I have no idea were to look at. How is it possible that some components work when hot ?

thesteve: what (where) are "upper address line"? And which are the RAM chips on the motherboard?

[thesteve]

its actually common to have chips that only work hot/cold