5200 No Power With Cartridge Inserted

[TissueLint]

Hey guys,

 

So I was working on replacing the crystal oscillator along with a recap kit into my semi-functional 5200. Once I got done I got busy with something else in the other room and when I came back without thinking I flipped the power on but I hadn’t trimmed the leads on the components. Needless to say it shorted out and now my 5200 displays a black screen with no cartridge inserted and when i insert a cartridge the power light will flicker one time but won’t actually turn on. I found that C116 was literally burnt in two so I replaced that but still no dice. I checked incoming power and its good. Upon checking the voltage regulators up top im getting 0.5 volts into the regulators. I’ve worked around the board checking various components and haven’t found any others that are bad. Only thing I found was that on the small transistors on the right side near the rf modulator one of them is outputting the 0.5 volts im seeing at the regulator. I have ordered two of those to replace the ones I currently have in the console. I’m assuming it’s something in the power circuit but everywhere I check I seem to be getting around 8-9 volts. Anyone else ever had this problem? Troubleshooting flowchart says it’s either a defective cartridge connector or an open somewhere in the console. I’m assuming my problem is somewhere in the power circuit since at the beginning of the circuit I have good voltage but after you go from the power circuit to the main 5v section there is nothing. I realize this is probably going to be a long deep rabbit hole but I would like to see if I can get this thing fully working. 

[+x=usr(1536)]

Is this a 2-port or 4-port model?  They're pretty close hardware-wise, but better to know for certain.

 

Also, is there any visible damage (e.g., scorch marks) from any of the components where uncut legs may have touched?  Have you checked for dry / cracked solder joints?

 

One thing to keep in mind about the 5200 is that it has two separate-ish power circuits, hence two voltage regulators.  If one VR is bad, you won't have power to the side of the board it covers.

 

A couple of years ago, I went down a power troubleshooting rabbit hole with my daily-driver 2-port.  As a general statement: a blown 4013 will prevent power from turning on. However, it's possible to have dead transistors that can give the appearance of a dead 4013 when the IC is actually OK.  I've also seen voltages above 5V on the board in conjunction with this problem and others.

 

Take a look at the thread linked below; it details what I went through including bridging legs on various transistors and getting power to come up.  It's not very long, about two-and-a-half pages.

 

 

[TissueLint]

6 minutes ago, x=usr(1536) said:

Is this a 2-port or 4-port model?  They're pretty close hardware-wise, but better to know for certain.

It is a 4-port model, no scorch marks are visible and I have not checked for any cracked solder joints but i have been going around and checking every component on the back side of the board and so far haven’t found anything much that stands out. Before this happened i was just getting a green screen and was never getting any games to load. But basically immediately when the legs shorted it went to the black screen issue without a cartridge inserted and a single flicker of light when one is inserted. 

[+x=usr(1536)]

49 minutes ago, TissueLint said:

It is a 4-port model, no scorch marks are visible and I have not checked for any cracked solder joints but i have been going around and checking every component on the back side of the board and so far haven’t found anything much that stands out. Before this happened i was just getting a green screen and was never getting any games to load. But basically immediately when the legs shorted it went to the black screen issue without a cartridge inserted and a single flicker of light when one is inserted. 

OK, the single LED flicker mirrors my experience.

 

Check that thread I linked to - it describes the transistors that may be responsible as well as a method for checking them.

[TissueLint]

On 4/29/2023 at 10:13 PM, x=usr(1536) said:

OK, the single LED flicker mirrors my experience.

 

Check that thread I linked to - it describes the transistors that may be responsible as well as a method for checking them.

Okay so small update, took me a minute to get around to doing some testing since I had to go to the hospital for my second daughter being born. But since we’ve been back home yesterday and today I finally got around to testing it and I found that one of the voltage regulators is working fine but the other one isn’t even getting any voltage. I’ve tracked the problem down to the lower green capacitor that is near the 7805 regulators. i’ve ordered both capacitors and both regulators figured since I was gonna replace that one might as well replace the other one as well as both regulators to give the console a little refresh. I also replaced the two transistors near the RF modulator and that cleared the problem up at that point. I’ll give another update when the new components come in and get installed. Thanks again for everyones help. 

Edited May 4, 2023 by TissueLint

[TissueLint]

@x=usr(1536) Another update:

 

Removed VR1 from the board and while it is removed the console will power up as normal with a cartridge inserted. Obviously it doesn’t function but at least the light stays on solid instead of no power. When I reinstall the original regulator it brings me back to the original problem of the dim flick of light no power issue. Two regulators were supposed to be delivered today but they were missent to another post office. I’ll post another update once I get the new regulator installed. A few of the capacitors I mentioned before were pretty out of spec so I went ahead and replaced those. Hopefully the new regulator will sort the issue out. Fingers crossed. 

[+-^CrossBow^-]

14 hours ago, TissueLint said:

@x=usr(1536) Another update:

 

Removed VR1 from the board and while it is removed the console will power up as normal with a cartridge inserted. Obviously it doesn’t function but at least the light stays on solid instead of no power. When I reinstall the original regulator it brings me back to the original problem of the dim flick of light no power issue. Two regulators were supposed to be delivered today but they were missent to another post office. I’ll post another update once I get the new regulator installed. A few of the capacitors I mentioned before were pretty out of spec so I went ahead and replaced those. Hopefully the new regulator will sort the issue out. Fingers crossed. 

Which caps? Because aside from the main filter cap and the audio poly caps, the rest is ceramic based and not likely to go bad?

 

[TissueLint]

7 hours ago, -^CrossBow^- said:

Which caps? Because aside from the main filter cap and the audio poly caps, the rest is ceramic based and not likely to go bad?

 

Yeah I thought from my measurements that they might have went bad when I shorted out those points on the bottom with the legs of the other capacitors but it’s been a wild goose chase. I suppose that’s what comes along with shorting out multiple spots on a board. C116 was the first thing I knew was bad since it was literally burnt in half. Other than that i’ve made some small progress but not much. 

[TissueLint]

@-^CrossBow^- @x=usr(1536)

 

Another thing I have noticed about this 5200 compared to my other ones that actually fully work is when i plug the rf cable into the switch box on my other 5200s i get the little relay click sound. When I plug this one in there is no click. Still get voltage to the console but no click like my other 5200s. Switchbox works fine with my other consoles as well. 

[TissueLint]

Major update! So I ordered some 3904 transistors from mouser and after I changed out Q8 and Q9 we now have a display! Now onto the next issue… The image is only displaying in black and white, i’m assuming that issue would have something to do with the RF modulator. I have tried swapping the chips back and forth between another fully functional unit with no change. I’m just relieved that it’s finally showing something other than a black screen. Still have the issue of the switchbox not making the click sound when its plugged in so that may also be related to the black and white image. I’ll keep this updated as I troubleshoot further. 

[+-^CrossBow^-]

Did you try to see if any color comes onto the screen or anything changes when trying the color adjustment trimmer? It is the larger of the two trimmers in the lower right corner of the console and the one closet to the right PCB edge.

 

 

[TissueLint]

On 5/15/2023 at 1:08 PM, -^CrossBow^- said:

Did you try to see if any color comes onto the screen or anything changes when trying the color adjustment trimmer? It is the larger of the two trimmers in the lower right corner of the console and the one closet to the right PCB edge.

 

 

Yes I tried adjusting the trimmer, you can tell it’s doing something but there is no color, it just subtly changes the shades of gray. I found that R115 is also broken, reason why i didn’t see it before is that it was broken off right at where the lead attaches to the resistor. Ordered some replacements for that and i’ll see if that makes any difference. I also noticed if i run the port test and use my loop back board it throws a fault for every single POT line but the controller works fine when im selecting a game or even playing missile command keypad also works fine. 

[+-^CrossBow^-]

26 minutes ago, TissueLint said:

Yes I tried adjusting the trimmer, you can tell it’s doing something but there is no color, it just subtly changes the shades of gray. I found that R115 is also broken, reason why i didn’t see it before is that it was broken off right at where the lead attaches to the resistor. Ordered some replacements for that and i’ll see if that makes any difference. I also noticed if i run the port test and use my loop back board it throws a fault for every single POT line but the controller works fine when im selecting a game or even playing missile command keypad also works fine. 

Don't know if you have mentioned it, but is this a 2 port or 4 port console? And which loopback are you using?

[TissueLint]

2 hours ago, -^CrossBow^- said:

Don't know if you have mentioned it, but is this a 2 port or 4 port console? And which loopback are you using?

4 port and the loopback I got from best electronics

[+-^CrossBow^-]

2 hours ago, TissueLint said:

4 port and the loopback I got from best electronics

Okay, which version of the diagnostics are you using?

[TissueLint]

10 hours ago, -^CrossBow^- said:

Okay, which version of the diagnostics are you using?

1.1, i believe its the same version you used in that video i watched when i was trying to fix my issue with my controller which ended up being the 4052s

[+-^CrossBow^-]

1 hour ago, TissueLint said:

1.1, i believe its the same version you used in that video i watched when i was trying to fix my issue with my controller which ended up being the 4052s

Then you shouldn't be getting any errors. What are the error codes that come up and have you compared them with the service manual?

[+x=usr(1536)]

18 hours ago, TissueLint said:

the loopback I got from best electronics

Do they still have these in stock?  Last I heard they were sold out.

[+-^CrossBow^-]

8 minutes ago, x=usr(1536) said:

Do they still have these in stock?  Last I heard they were sold out.

Someone advised me recently that apparently some more had been 'found'. I've not reached out but I do need to get one of the 2 port loopbacks for service work since the 4 port, while I can use it for pokey adjustments, will cause port failures in testing with 2 port units.

 

 

 

[+x=usr(1536)]

11 minutes ago, -^CrossBow^- said:

Someone advised me recently that apparently some more had been 'found'. I've not reached out but I do need to get one of the 2 port loopbacks for service work since the 4 port, while I can use it for pokey adjustments, will cause port failures in testing with 2 port units.

Interesting.  I'll have to look into that.  Thanks for the heads-up.

 

Out of curiosity, do you happen to know the differences between the 2-port and 4-port boards, or have hi-res pictures that could be used to compare traces and components?  This is something that should really be remade in a modern design if at all possible, and having them be 2-/4-port switchable would be a plus.

 

(FWIW, I am aware of this project on PCBway, but would like to keep closer to the original design.)

[+-^CrossBow^-]

I made scans of my 4 port board sometime back for others here. Search the forums they can be found and I was able to figure out the traces pretty well and I think I might have even labeled the components? There aren't many there. I've never seen the 2 port model so I don't know exactly what it looks like but I'd image it to look like the 4 port but with only have the components?

 

[+x=usr(1536)]

20 minutes ago, -^CrossBow^- said:

I made scans of my 4 port board sometime back for others here. Search the forums they can be found and I was able to figure out the traces pretty well and I think I might have even labeled the components? There aren't many there.

Now that you mention it, I did get a copy of the 4-port scans from you a while back.  Not at home right now (travelling), so don't have access to them, but do recall getting them from you.

21 minutes ago, -^CrossBow^- said:

I've never seen the 2 port model so I don't know exactly what it looks like but I'd image it to look like the 4 port but with only have the components?

Something tells me that there were changed values on some of the components and that some type of termination or similar was added in.  I'll have to do some digging.

[RB5200]

3 hours ago, -^CrossBow^- said:

Someone advised me recently that apparently some more had been 'found'. I've not reached out but I do need to get one of the 2 port loopbacks for service work since the 4 port, while I can use it for pokey adjustments, will cause port failures in testing with 2 port units.

 

 

 

The 2 port board will also give you the errors. These are the errors you get, but ignore since it is a 2 port machine. 8,9,10,11,13,14,15,26,27,28,29. Everything will be the same as using the 4 port board.

Edited May 18, 2023 by RB5200

[TissueLint]

18 hours ago, x=usr(1536) said:

Do they still have these in stock?  Last I heard they were sold out.

I got mine not too long ago maybe a month or so. They were in stock then he didn’t mention being low on stock or anything

[TissueLint]

23 hours ago, -^CrossBow^- said:

Then you shouldn't be getting any errors. What are the error codes that come up and have you compared them with the service manual?

I’m getting error codes 22,23,24,25,26,27,28,29 on two of my 5200s (one of them is the one i shorted out) and then error code 22 on my main 5200 i play games on. They all seem to work perfectly though with the controllers so thats what i find odd. I did look in the service manual and seen that these are all POT Line error codes

Edited May 18, 2023 by TissueLint