Restore of a nice Donkey Kong - COMPLETE

[Maximus]

This seems to confirm the mysterious 2-line yet PP-7B AC-Input, mine's exactly the same...

[Maximus]

Caps are at 6 & 7 so its definitely a B

[Maximus]

OK board on its own


Then plugged into transformers

[Nephasth]

Pretty smoke ring!

[Maximus]

Pretty smoke ring!

They cost 50c a shot

[welash]

Are the transformers on a separate board with other parts (transistors, resistors, ics, ...) or are they just transformers with connectors on cables?  If it is another board, do you have a picture?  I'm guessing that they just didn't mark the connectors on the B schematic, and the schematic shows the parts on both the boards. 

Do you have a multimeter or anything to check continuity?

[Maximus]

Yes they are all on another board with ic and other stuffs. Yes I have a decent multimeter but no experience testing circuits

[Maximus]

Here's the other part of the supply

[welash]

Looks like it is kind of packed in there. I think the right side of R1 will go to one side of either C6 or C7, and then go to a pin on one of the connectors.  I think the other side of that capacitor will go to a different pin on one of the connectors.  If you can figure out which pins those are, if you use your multimeter to do a continuity check (or diode test, as it is labeled on many multimeters) between those two pins on the other board (the one with most of the transformers) you should see a short (0 ohms) if you have the probes one way and should look like an open in the other direction (the transformer coil will look like a short to DC, and the Diodes D2 and D7 will conduct in one direction and not in the other, In both cases the transistors shouldn't be conducting).  If it looks like a short with the probes either way, something is wrong with either the diodes or the transistors (TR1 or TR3).

If that looks ok, then something must be turning at least one of those transistors on more or less constantly.

[jennifer]

    You gotta pull @ least 1 leg of the cap under test or you may get a false reading from a bad component elsewhere.

[404]

Yes they are all on another board with ic and other stuffs. Yes I have a decent multimeter but no experience testing circuits

just because it pops when adding power doesn't necessarily mean that the power supply is at fault here. Be sure to test the surrounding circuits on the board.

Hopefully someone with some direct DK experience can chime in soon. In the meantime, you can check out some basic testing vids from youtube that should help you probe around the board.

[welash]

    You gotta pull @ least 1 leg of the cap under test or you may get a false reading from a bad component elsewhere.

I guess I wasn't clear, I was suggesting disconnecting the two boards, and testing continuity on the board with the transformers.  I don't think there will be any capacitors to charge in that case.  But you are right, having capacitors  in the path (especially big ones) will make it difficult to check continuity.

[Maximus]

Ok looks like I have to test tr1 and tr3, no idea how exactly, I'll search around for some kind of dummies guide. I know you guys are trying to be helpful, but even your version of 'basic' language here is confusing me, I guess I don't have the engineer gene 

As Welash mentioned earlier I now understand that if either of the two transistors are jammed open then they could be just dumping current out onto the r1, although strange that the fuse never blows no??

Found these though so this should help a bit

[Maximus]

Ok I think i have a grasp of the basics on how to test a transistor so I can start there, do I have to pull them from the board to test or can I do it in place?

[welash]

To do a full test of the transistor you would need to pull it, but if it is shorted, you may be able to just check continuity between the Collector and Emitter (looks like it is pins 2 and 3 from the data sheet).  If it is conducting (in either direction) with no input at the base, it is bad.  You might also be able to do a basic test without removing it from the board, but by lifting either the collector or emitter (the emitter would be easier, as it is pin 3).

As to why the resistor blows instead of the fuse, the resistor is trying to dissipate about 500 watts (100 volts across 20 ohms) it is rated at 2 watts, so it blows pretty fast.  It should be pulling close to 5 amps, so the fuse (4 amp) should blow, but my guess is that as the resistor heats up its resistance increases a little and the resistor blows quickly enough that the fuse doesn't blow.  It is also possible that someone put in a larger fuse.

That debugging flowchart is pretty nice.  Hopefully it is just one of the transistors.  I actually hope that when you examine the board around the transistors, you'll find a solder bridge or piece of metal shorting out one of the transistors.

[Maximus]

Yep I'll try this tonight and see if I can get any further.

I ordered another pp7B PSU off eBay just in case I find myself in a corner burning way too much time on this. At some point I have to know when to walk away and just replace the piece as I have too many projects sitting in wait for this to grind on for too long. I'm still waiting on some other parts for my DK, so I'll try with this until they arrive, after that I'll just opt for the replacement

[Nephasth]

I ordered another pp7B PSU off eBay just in case I find myself in a corner burning way too much time on this. At some point I have to know when to walk away and just replace the piece as I have too many projects sitting in wait for this to grind on for too long. I'm still waiting on some other parts for my DK, so I'll try with this until they arrive, after that I'll just opt for the replacement

 

You threw the towel in too early. Why even bother to try to fix stuff?

[Maximus]

I'm still going to try on this, just not going to let it hold everything up. I f I fix it then great I'll have a spare Nintendo pp7b tested and working.

[Maximus]

Wood repair done, unnecessary bolt holes filled and started surface prep

[Maximus]

Back door repainted

[Maximus]

Tested TR3 out of the chassis and it is conducting on every leg in every direction so I'm assuming that's bad.

Tested TR1 that only conducts on the outside legs but does it in both directions, not sure if that's OK or not.

TR3 is T C2535 .1
TR1 is T C2555 .11

None if the diodes seem to be shorted, so if I'm lucky TR3 is my problem component.

Tried looking on mouser for this but couldn't find it, can someone help me find a replacement to order?

[jennifer]

     You can swap the PS for a switcher, and see if that gets it up, and/or unplug the monitor AC and see if it still pops the fuse. At least it will isolate the problem... Caps, transistors, or rectifers are most likely suspect.

[Maximus]

     You can swap the PS for a switcher, and see if that gets it up, and/or unplug the monitor AC and see if it still pops the fuse. At least it will isolate the problem... Caps, transistors, or rectifers are most likely suspect.

The monitor AC is completely independent and the resistor blows without any boards plugged in anyway.

[Nephasth]

Tested TR3 out of the chassis and it is conducting on every leg in every direction so I'm assuming that's bad.

Stop assuming. There's plenty of information on the net about how to test transistors and other circuit board components. Take the time, do the research, and know what is failing. Stop getting in a rush. If you get hung up on this, you've got plenty of other irons in the fire to direct your attention towards. Taking the time to gain some knowledge is more than worth it. You don't gain anything by taking shortcuts.

[Maximus]

Easy Sally. Conducting in all directions on b
All legs means its guaranteed dead I was just using a figure of speech.

[mcseforsale]

Problem with that type of rust is it can come back.  Next time, convert it with this stuff:



Otherwise, that thing looks awesome? 

AJ

[welash]

Tested TR3 out of the chassis and it is conducting on every leg in every direction so I'm assuming that's bad.

Tested TR1 that only conducts on the outside legs but does it in both directions, not sure if that's OK or not.

TR3 is T C2535 .1
TR1 is T C2555 .11

None if the diodes seem to be shorted, so if I'm lucky TR3 is my problem component.

Tried looking on mouser for this but couldn't find it, can someone help me find a replacement to order?

Looking at: http://alltransistors.com/transistor.php?transistor=13342 if you click on the cross reference table, the BUL45D2  should be a drop in replacement.  On mouser, they say that the BUL45D2 has been replaced by the BUL45D2G which is available for about a buck a piece.

I don't find a good replacement for the c2555 (at least not a cheap one available from a convenient source in a TO-218 package).  From what you found, I am a little concerned about the c2555.  The Base/emitter should act as a diode, and the base/collector should also act as a diode.

[Le Chuck]

Problem with that type of rust is it can come back.  Next time, convert it with this stuff:



Otherwise, that thing looks awesome? 

AJ

Holy CRAP!  That stuff is powerful.  It converts reality without even opening the can.  Griff, tread carefully, interdimensionsal sprays are not to be trifled with. 

[Maximus]

That's probably what you see when using the stuff in an unventilated area

[Malenko]

looks like a chic fil a cup to the right, maybe a box of pop tarts to the left?

[Le Chuck]

looks like a chic fil a cup to the right, maybe a box of pop tarts to the left?

According to the list on the fridge they're out of milk and laundry soap

[Gamester]

looks like a chic fil a cup to the right, maybe a box of pop tarts to the left?

That's not just any chic fil a cup...that's a milkshake! Mmmmm....

[Maximus]

Lol you guys really need to get out more.

ONWARD WITH THE PICTURETOGRAPHS!!!!


Nasty ass 30 year old glue removed, took a lot of alcohol, some of it I used on the glue BADDA BING!!!!


New black paint all around


Close up of the refinished marquee retainers


All ready for blue vinyl from Rich, also instruction cards, stickers and of course screen printed side art from Quarter Arcade


Coin mechs all cleaned and reassembled on the slots

[Maximus]

Door reassembled and ready to go back in the cab

[Malenko]

you are easily going to have the most beautiful non working DK cab ever.

[HaRuMaN]

you are easily going to have the most beautiful non working DK cab ever.

 

[Maximus]

you are easily going to have the most beautiful non working DK cab ever.

LOL. yeah but think of the energy savings.


Control panel prepped and ready for vinyl and instruction cards/stickers


Pulled all the boards from the EZV without incident, ready for capping. Thanks to Paigeoliver who offered his services to do the work on this, I'm going to try and do it myself first with a full cap kit and b+ pot that's on the way already. Apparently these Sanyo's are not easy to work on, but I'm just going to take my time and see what I can do.

[Maximus]

Bob Roberts Cap-Map for the EZ, sticking it here for reference.

[dandro]

apparently, "daddy needs sleep" lol

looking real good, man those coin mechs look mint.

[Maximus]

Looking at: http://alltransistors.com/transistor.php?transistor=13342 if you click on the cross reference table, the BUL45D2  should be a drop in replacement.  On mouser, they say that the BUL45D2 has been replaced by the BUL45D2G which is available for about a buck a piece.
I don't find a good replacement for the c2555 (at least not a cheap one available from a convenient source in a TO-218 package).  From what you found, I am a little concerned about the c2555.  The Base/emitter should act as a diode, and the base/collector should also act as a diode.

Thanks Welash, I'll take a look at that link for the BUL45D2G.

The c2555 seemed to be working properly from what I could work out, although of course my knowledge is minimal at this point.

Thanks Dandro, yeah the coins came out well, the overall condition of the cab is making this a pretty easy resto, it must have been sitting for a long time as it just doesn't have that 'worn' feel about it. Wooden corners are sharp and clean, no extra screw holes here and there, no chopped wires or snapped wire clips. I'm pretty excited for all the vinyl and stickers to arrive today as that will pretty much complete the whole cab itself, and then it will indeed be the prettiest Donkey Kong shaped paper weight.