Intellivision graphics corruption

[IMBerzerk]

3 hours ago, kevincondrick@gmail.com said:

Yah it works that's what I used. Like a socketed ic connecter. I soldered it on the cable and it fits in the holes perfect ?

This is a great candidate for a write-up and a sticky... think maybe you could take some pics and provide part numbers?   A lot of PCB repairs would benefit from replacing that crap ribbon.

 

Edited May 12, 2020 by IMBerzerk

[kevincondrick@gmail.com]

3 hours ago, IMBerzerk said:

This is a great candidate for a write-up and a sticky... think maybe you could take some pics and provide part numbers?   A lot of PCB repairs would benefit from replacing that crap ribbon.

 

Well I'm just an amature trying to get my intv working. But if you want I can show you what I did. Idk what parts I even used lol I just found a old cable I cold rig something up to

[kevincondrick@gmail.com]

Dose anyone know if the L7812 voltage regulators the same a UA7812

[kevincondrick@gmail.com]

2 hours ago, kevincondrick@gmail.com said:

Dose anyone know if the L7812 voltage regulators the same a UA7812

I put it in circuit and it seams to work. I have yet to test for a long period of time but as or right now it seams to work fine ?

[+KylJoy]

Let's see pics of it working!

[kevincondrick@gmail.com]

1 hour ago, KylJoy said:

Let's see pics of it working!

Pictures fuzzy but I think that's just cuz of the rf

[+KylJoy]

Progress happening!

[kevincondrick@gmail.com]

Success!! 

 

Although it was a rollercoaster of emotions

I think I did find the problem. 

 

Well it's almost a successful run but I'm still happy.

 

Ok I do believe that the main problem was that UA7812 cuz I've been playing it for about an hour but it did get really hot and eventually stopped working. But it was a much longer time then last time and this time it seams the cpu was getting hot so maybe that's another problem. But idk I'm happy that it dose run for a longer period of time. I am planning on changing out the that UA 7805 to but I think it can only get better from here ? also I Don't think it's something wrong with the logic board cuz I did get another logic board and I plugged it in to and it did shut off to do it's definitely something on the power supply/ or the transformer. I have a few more test to do but we are definitely getting somewhere ??

Edited May 16, 2020 by kevincondrick@gmail.com

[ChildOfCv]

On 5/15/2020 at 1:50 PM, kevincondrick@gmail.com said:

Dose anyone know if the L7812 voltage regulators the same a UA7812

Most manufacturers will use the same basic part number (maybe a couple extra letters) for the same component.  But if it's a 12V regulator with the same pinout, that's all it needs to be.

 

When it was working, did you happen to take voltage measurements?  (Yellow is ground attach point for multimeter)

 

Edited May 16, 2020 by ChildOfCv

[kevincondrick@gmail.com]

4 hours ago, ChildOfCv said:

Most manufacturers will use the same basic part number (maybe a couple extra letters) for the same component.  But if it's a 12V regulator with the same pinout, that's all it needs to be.

 

When it was working, did you happen to take voltage measurements?  (Yellow is ground attach point for multimeter)

 

Well it was a worry at first cuz I put one in and it instently got fryed. But then I noticed that it just shorted to the ground pin. But I did put in another one and it worked fine and it might've been the whole problem. Cuz iv played games for over an hour and it all worked fine although it got real hot after awhile. But it all worked 

[+-^CrossBow^-]

The VRs in the Intelly do get really hot. Especially the 7805. it is the only classic console I've seen that has a heatsink the 7805 bolts onto, and also has another smaller heatsink that attached ontop of the 7805. I ended up replacing both VRs out with DC-DC converters. The only heat in the system now is that from the transformer and the main ICs on the main logic board.

 

[kevincondrick@gmail.com]

5 minutes ago, -^CrossBow^- said:

The VRs in the Intelly do get really hot. Especially the 7805. it is the only classic console I've seen that has a heatsink the 7805 bolts onto, and also has another smaller heatsink that attached ontop of the 7805. I ended up replacing both VRs out with DC-DC converters. The only heat in the system now is that from the transformer and the main ICs on the main logic board.

 

Well I'm still just wondering how long it'll be till they go bad again. Also I didn't know this but apparently on somegames it'll to to like a standby mode after so long. I know on astrosmash it dose.

Edited May 17, 2020 by kevincondrick@gmail.com

[+-^CrossBow^-]

Also, while not an exact match. I actually have a local source for near exact replacement ribbon power cables that were used on the Intelly model 1 units. The ones I get are a tiny bit longer and have 6 pins on them vs the 5 needed. But I just use a pair of scissors to cut up along the ribbon to remove that 6th pin and turn it into a 5pin ribbon cable or simple cut the leads off one side of the cable so that only 5 of the 6 pins can be used.

 

I've also just soldered on machine pin headers into those spots where the ribbon cable was and used standard stranded wire with solder on machine pins to the ends to insert into the machine pin socket I soldered to the board. Not specific part numbers, just get rows of them and break off 5 together as needed. But the ribbon cable replacements I purchased do the job just as well as the originals and are new and require less work to replace out.

 

[ChildOfCv]

1 hour ago, -^CrossBow^- said:

The VRs in the Intelly do get really hot. Especially the 7805. it is the only classic console I've seen that has a heatsink the 7805 bolts onto, and also has another smaller heatsink that attached ontop of the 7805. I ended up replacing both VRs out with DC-DC converters. The only heat in the system now is that from the transformer and the main ICs on the main logic board.

 

I've thought of designing a power board that uses nothing but buck converters for all voltages.  That would also help cool down those two transistors.  But the sticking point there would be that it would be my first real power supply project   On the other hand, that's what makes it fun.

[kevincondrick@gmail.com]

17 hours ago, ChildOfCv said:

I've thought of designing a power board that uses nothing but buck converters for all voltages.  That would also help cool down those two transistors.  But the sticking point there would be that it would be my first real power supply project

So yah I have it put in with the L7812 and it will work ok with the heat sink on but like if I leave it on to long it will get really hot and screw up but I don't have any thermal paste. What do you suggest the best stuff to use is?

 

The other PCB has the same L7812 and no heat sink on it and it seams to work better / cooler. Mind that one the first pcb that I replaced just about everything on it except the 7805 regulator and the diodes. So you think it's just running hot cuz of the dioeds or the other voltage regulator? So the problem is definitely from the 7812. I know that cuz I did it without a heatsink and it screwed up in like 3 mins. Wile with the heat sink it's maybe 30 mins to an hour with no thermal paste. You think the thermal paste will make it last alot longer? Or could there be some better solution.

[ChildOfCv]

10 hours ago, kevincondrick@gmail.com said:

So yah I have it put in with the L7812 and it will work ok with the heat sink on but like if I leave it on to long it will get really hot and screw up but I don't have any thermal paste. What do you suggest the best stuff to use is?

 

The other PCB has the same L7812 and no heat sink on it and it seams to work better / cooler. Mind that one the first pcb that I replaced just about everything on it except the 7805 regulator and the diodes. So you think it's just running hot cuz of the dioeds or the other voltage regulator? So the problem is definitely from the 7812. I know that cuz I did it without a heatsink and it screwed up in like 3 mins. Wile with the heat sink it's maybe 30 mins to an hour with no thermal paste. You think the thermal paste will make it last alot longer? Or could there be some better solution.

Thermal paste is made to help the chip transfer heat, so yeah it should help.  Use as little as possible but create solid contact between the chip and the heat sink.  It just needs to be a solid film, but as thin as you can make it.  Also, make sure the chip is seated firmly on the heat sink and screwed down before soldering the legs, so that the legs don't hold the chip off the heat sink.

 

As an alternative, you could get thermal pad material and cut of just enough to fit under the regulator.  https://www.amazon.com/Innovation-Cooling-Graphite-Thermal-Pad/dp/B07CKVW18G/

 

It's hard to imagine that the diodes have that much impact on the power consumption.  Well, unless one or more of the diodes on the cooler board are dead.  That would reduce the transferred power, and assuming it's still enough for the Inty, that would be one way to cool it down.  In the diagram I posted above with numbers for AC and DC readings, take those readings.  But on the DC side, also take AC readings.  The AC readings at the DC points ought to be near 0 if things are working correctly.

 

Edited May 18, 2020 by ChildOfCv

[kevincondrick@gmail.com]

Well I put the heat sinks on and put it all back together and it all worked!! Thanks everyone for your help!!! I'm happy to get this working once again.